Traffic and highway engineering (fourth edition) part 2

P A R T Transportation Planning T he process of transportation planning involves the elements of situation and problem definition, search for solutions and performance analysis, as well as evaluation and choice of project The process is useful for describing the effects of a proposed transportation alternative and for explaining the benefits to the traveler of a new transportation system and its impacts on the community The highway and traffic engineer is responsible for developing forecasts of travel demand, conducting evaluations based on economic and noneconomic factors, and identifying alternatives for short-, medium-, and long-range purposes C H A P T E R 11 CHAPTER 12 The Transportation Planning Process Basic Elements of Transportation Planning Transportation Planning Institutions Urban Transportation Planning Forecasting Travel Summary Problems References Forecasting Travel Demand Demand Forecasting Approaches Trip Generation Trip Distribution Mode Choice Traffic Assignment Other Methods for Forecasting Demand Estimating Freight Demand Traffic Impact Studies Summary Problems References 549 www.EngineeringEBooksPdf.com 550 Part Transportation Planning CHAPTER 13 Evaluating Transportation Alternatives Basic Issues in Evaluation Evaluation Based on Economic Criteria Evaluation Based on Multiple Criteria Summary Problems References NEL www.EngineeringEBooksPdf.com C H A P T E R 11 The Transportation Planning Process T his chapter explains how decisions to build transportation facilities are made and highlights the major elements of the process Transportation planning has become institutionalized; federal guidelines, regulations, and requirements for local planning are often driving forces behind existing planning methods The formation of the nation’s transportation system has been evolutionary, not the result of a grand plan The system now in place is the product of many individual decisions to select projects for construction or improvement, such as bridges, highways, tunnels, harbors, railway stations, and airport runways These transportation projects were selected because a conclusion was reached that the project would result in overall improvements to the system Among the factors that may justify a transportation project are improvements in traffic flow and safety, energy consumption, travel time, economic growth, and accessibility Some transportation projects may have been selected for reasons unrelated to specific benefits, for example, to stimulate employment in a particular region, to compete with other cities or states for prestige, to attract industry, to respond to pressures from a political constituency, or to gain personal benefit from a particular route location or construction project In some instances, transportation projects are not selected because of opposition from those who would be adversely affected For example, a new highway may require the taking of community property, or the construction of an airport may introduce undesirable noise due to low-flying planes or take residential or wetland acreage to accommodate runway expansion Whatever the reason for selecting or rejecting a transportation project, a specific process led to the conclusion to build or not to build The process for planning transportation systems should be a rational one that serves to furnish unbiased information about the effects that the proposed transportation project will have on the affected community and on users For example, if noise or air pollution is a concern, the process will examine and estimate how much 551 www.EngineeringEBooksPdf.com 552 Part Transportation Planning additional noise or air pollution will occur if the transportation facility is built Usually, cost is a major factor, and so the process will include estimates of the construction, maintenance, and operating costs The process must be flexible enough to be applicable to any transportation project or system, because the kinds of problems that transportation engineers work on will vary over time Transportation has undergone considerable change in emphasis over a 200-year period; such modes as canals, railroads, highways, air, and public transit have each been dominant at one time or another Thus, the activities of transportation engineers have varied considerably during this period, depending on society’s needs and concerns Examples of changing societal concerns include energy conservation, traffic congestion, environmental impacts, safety, security, efficiency, productivity, and community preservation The transportation planning process is not intended to furnish a decision or to give a single result that must be followed, although it can so in relatively simple situations Rather, the process is intended to provide the appropriate information to those who will be affected and those responsible for deciding whether the transportation project should go forward 11.1 BASIC ELEMENTS OF TRANSPORTATION PLANNING The transportation planning process comprises seven basic elements, which are interrelated and not necessarily carried out sequentially The information acquired in one phase of the process may be helpful in some earlier or later phase, so there is a continuity of effort that should eventually result in a decision The elements in the process are: • • • • • • • Situation definition Problem definition Search for solutions Analysis of performance Evaluation of alternatives Choice of project Specification and construction These elements are described and illustrated in Figure 11.1, using a scenario involving the feasibility of constructing a new bridge 11.1.1 Situation Definition The first step in the planning process is situation definition, which involves all of the activities required to understand the situation that gave rise to the perceived need for a transportation improvement In this phase, the basic factors that created the present situation are described, and the scope of the system to be studied is delineated The present system is analyzed and its characteristics are described Information about the surrounding area, its people, and their travel habits may be obtained Previous reports and studies that may be relevant to the present situation are reviewed and www.EngineeringEBooksPdf.com Chapter 11 The Transportation Planning Process The Process Application to Bridge Study Situation Definition Inventory transportation facilities Measure travel patterns Review prior studies Problem Definition Define objectives • Reduce travel time Establish criteria • Average delay time Define constraints Establish design standards Search for Solutions Consider options • Locations and types • Tunnel or don t build • Toll charges Analysis of Performance Evaluation of Alternatives 553 For each option, determine • Cost • Traffic flow • Impacts For bridge project, determine • Benefits vs cost • Profitability • Cost-effectiveness Choice of Project Consider factors involved: • Revenue cost forecast • Site location • Political judgment Specification and Construction Design of bridge • Superstructure • Piers, foundation Construction plans • Contractor selection Transfer of completed bridge to authority for operation and maintenance Figure 11.1 Basic Elements in the Transportation Planning Process Applied to Consider the Feasibility of a New Bridge summarized Both the scope of the study and the domain of the system to be investigated are delineated In the example described in Figure 11.1, a new bridge is being considered Situation definition involves developing a description of the present highway and transportation services in the region; measuring www.EngineeringEBooksPdf.com 554 Part Transportation Planning present travel patterns and highway traffic volumes; reviewing prior studies, geological maps, and soil conditions; and delineating the scope of the study and the area affected A public hearing might also be held to obtain citizen input The situation then will be described in a report that documents the overall situation and summarizes the results of the public hearing 11.1.2 Problem Definition The purpose of this step is to describe the problem in terms of the objectives to be accomplished by the project and to translate those objectives into criteria that can be quantified Objectives are statements of purpose, such as to reduce traffic congestion; to improve safety; to maximize net highway-user benefits; and to reduce noise Criteria are the measures of effectiveness that can be used to quantify the extent to which a proposed transportation project will achieve the stated objectives For example, the objective “to reduce traffic congestion” might use “travel time” as the measure of effectiveness The characteristics of an acceptable system should be identified, and specific limitations and requirements should be noted Also, any pertinent standards and restrictions that the proposed transportation project must conform to should be understood Referring to Figure 11.1, an objective for the bridge project might be to reduce travel congestion on other roads or to reduce travel time between certain areas The criterion used to measure how well these objectives are achieved is average delay or average travel time Constraints placed on the project might be physical limitations, such as the presence of other structures, topography, or historic buildings Design standards for bridge width, clearances, loadings, and capacity also should be noted 11.1.3 Search for Solutions In this phase of the planning process, consideration is given to a variety of ideas, designs, locations, and system configurations that might provide solutions to the problem This is the brainstorming stage, in which many options may be proposed for later testing and evaluation Alternatives can be proposed by any group or organization In fact, the planning study may have been originated to determine the feasibility of a particular project or idea, such as adding bike lanes to reduce traffic volumes The transportation engineer has a variety of options available in any particular situation, and any or all may be considered in this idea-generating phase Among the options that might be used are different types of transportation technology or vehicles, various system or network arrangements, and different methods of operation This phase also includes preliminary feasibility studies, which might narrow the range of choices to those that appear most promising Some data gathering, field testing, and cost estimating may be necessary at this stage to determine the practicality and financial feasibility of the alternatives being proposed In the case of the bridge project, a variety of options may be considered, including different locations and bridge types The study should also include the option of not building the bridge and might also consider what other alternatives are available, such as a tunnel or an alternate route Operating policies should be considered, including various toll charges and methods of collection www.EngineeringEBooksPdf.com Chapter 11 The Transportation Planning Process 555 11.1.4 Analysis of Performance The purpose of performance analysis is to estimate how each of the proposed alternatives would perform under present and future conditions The criteria identified in the previous steps are calculated for each transportation option Included in this step is a determination of the investment cost of building the transportation project, as well as annual costs for maintenance and operation This element also involves the use of mathematical models for estimating travel demand The number of persons or vehicles that will use the system is determined, and these results, expressed in vehicles or persons/hour, serve as the basis for project design Other information about the use of the system (such as trip length, travel by time of day, and vehicle occupancy) are also determined and used in calculating user benefits for various criteria or measures of effectiveness Environmental effects of the transportation project (such as noise and air pollution levels and acres of land required) are estimated These nonuser impacts are calculated in situations where the transportation project could have significant impacts on the community or as required by law This task is sometimes referred to as the transportation planning process, but it is really a systems analysis process that integrates system supply on a network with travel demand forecasts to show equilibrium travel flows The forecasting-model system and related network simulation are discussed in Chapter 12 To analyze the performance of the new bridge project, first prepare preliminary cost estimates for each location being considered Then compute estimates of the traffic that would use the bridge, given various toll levels and bridge widths The average trip length and average travel time for bridge users would be determined and compared with existing or no-build conditions Other impacts (such as land required, visual effects, noise levels, and air or water quality changes) also would be computed 11.1.5 Evaluation of Alternatives The purpose of the evaluation phase is to determine how well each alternative will achieve the objectives of the project as defined by the criteria The performance data produced in the analysis phase are used to compute the benefits and costs that will result if the project is selected In cases where the results cannot be reduced to a single monetary value, a weighted ranking for each alternative might be produced and compared with other proposed projects For those effects that can be described in monetary terms, the benefit–cost ratio (described in Chapter 13) for each project is calculated to show the extent to which the project would be a sound investment Other economic tests might also be applied, including the net present worth of benefits and costs In situations where there are many criteria, particularly in an environmental analysis, the results can be shown in a cost-effectiveness matrix (for example, project cost versus number of homes displaced) that will furnish a better understanding as to how each alternative performs for each of the criteria and at what cost The results can be plotted to provide a visual comparison of each alternative and its performance In the evaluation of the bridge project, first determine the benefits and costs and compute the benefit–cost ratio If the result is positive, the evaluation of alternative www.EngineeringEBooksPdf.com 556 Part Transportation Planning sites requires additional comparison of factors, both for engineering and economic feasibility and for environmental impact A cost-effectiveness matrix that compares the cost of each alternative with its effectiveness in achieving certain goals will further assist in the evaluation 11.1.6 Choice of Project Project selection is made after considering all the factors involved In a simple situation, for example, where the project has been authorized and is in the design phase, a single criterion (such as cost) might be used and the chosen project would be the one with the lowest cost With a more complex project, however, many factors have to be considered, and selection is based on how the results are perceived by those involved in decision-making If the project involves the community, it may be necessary to hold additional public hearings A bond issue or referendum may be required It is possible that none of the alternatives will meet the criteria or standards, and additional investigations will be necessary The transportation engineer, who participates in the planning process, may have developed a strong opinion as to which alternative to select Such bias could result in the early elimination of promising alternatives or the presentation to decision-makers of inferior projects If the engineer is acting professionally and ethically, he or she will perform the task such that the appropriate information is provided to make an informed choice and that every feasible alternative has been considered Before deciding whether or not to build the proposed bridge, decision-makers look carefully at the revenue-cost forecasts and would likely consider projects that appear to be financially sound The site location is selected based on a careful study of the factors involved The information gathered in the earlier phases would be used, together with engineering judgment and political considerations, to arrive at a final project selection 11.1.7 Specification and Construction Once the transportation project has been selected, the project moves into a detailed design phase in which each of the components of the facility is specified For a transportation facility, this involves its physical location, geometric dimensions, and structural configuration Design plans are produced that can be used by contractors to estimate the cost of building the project When a construction firm is selected, these plans will be the basis on which the project will be built For the bridge project, once a decision to proceed has been made, a design is produced that includes the type of superstructure, piers and foundations, roadway widths and approach treatment, as well as appurtenances such as tollbooths, traffic signals, and lighting These plans are made available to contractors, who submit bids for the construction of the bridge If a bid does not exceed the amount of funds available and the contractor is deemed qualified to the work, the project proceeds to the construction phase Upon completion, the new bridge is turned over to the local transportation authority for operation and maintenance www.EngineeringEBooksPdf.com Chapter 11 The Transportation Planning Process 557 Example 11.1 Planning the Relocation of a Rural Road To illustrate the transportation planning process, a situation that involves a rural road relocation project is described Each of the activities that are part of the project is discussed in terms of the seven-step planning process previously described This project includes both a traffic analysis and an environmental assessment and is typical of those conducted by transportation consultants or metropolitan transportation organizations (This example is based on a study completed by the engineering firm, Edwards and Kelsey.) Step Step Situation definition The project is a proposed relocation or reconstruction of 3.3 miles of U.S 1A located in the coastal town of Harrington, Maine The town center, a focal point of the project, is located near the intersection of highways U.S and U.S 1A on the banks of the Harrington River, an estuary of the Gulf of Maine (See Figure 11.2.) The town of Harrington has 553 residents, of whom 420 live within the study area and 350 live in the town center The population has been declining in recent years; many young people have left because of the lack of employment opportunities Most of the town’s industry consists of agriculture or fishing, so a realignment of the road that damages the environment would also affect the town’s livelihood There are 10 business establishments within the study area; 20 percent of the town’s retail sales are tourism related The average daily traffic is 2620 vehicles/day, of which 69 percent represent through traffic and 31 percent represent local traffic Problem definition The Maine Department of Transportation wishes to improve U.S 1A, primarily to reduce the high accident rate on this road in the vicinity of the town center The problem is caused by a Figure 11.2 Location Map for Highways U.S and U.S 1A www.EngineeringEBooksPdf.com 558 Part Transportation Planning Step narrow bridge that carries the traffic on U.S 1A into the town center, the poor horizontal and vertical alignment of the road within the town center, and a dangerous intersection where U.S 1A and U.S meet The accident rate on U.S 1A in the vicinity of the town center is four times the statewide average A secondary purpose of the proposed relocation is to improve the level of service for through traffic by increasing the average speed on the relocated highway The measures of effectiveness for the project will be the accident rate, travel time, and construction cost Other aspects that will be considered are the effects that each alternative would have on a number of businesses and residences that would be displaced, the changes in noise levels and air quality, and the changes in natural ecology The criteria that will be used to measure these effects will be the number of businesses and homes displaced, noise levels and air quality, and the acreage of salt marsh and trees affected Search for solutions The Department of Transportation has identified four alternative routes, as illustrated in Figure 11.3, in addition to the present route—Alternative 0—referred to as the null or “donothing” alternative All routes begin at the same location—3 miles southwest of the center of Harrington—and end at a common point northeast of the town center The alternatives are as follows: • Alternative 1: This road bypasses the town to the south on a new location across the Harrington River The road would have two lanes, each 12-ft wide with 8-ft shoulders A new bridge would be constructed about one-half mi downstream from the old bridge Figure 11.3 Alternative Routes for Highway Relocation www.EngineeringEBooksPdf.com 1216 Index Gradation of aggregates (continued) size, 1005 superpave systems, 1005 –1008 Grade equivalent (GE), 1053 –1056 Grade resistance, 74 –75 Grades, 387, 392, 408, 414 – 418, 427– 428, 438 – 439, 445, 447, 469, 723 –730, 753 –754, 754 –760, 996 –1002 adjustment factor (fG), 388, 438-439, 445, 447, 469 alignment of highways and, 754 –760 asphalt binder performance, 996 –1002 composite, 415 – 418 cross sections of, 723 –726 downgrades, 392, 414 – 415 earthwork and, 723 –730 freeways, 408, 414 – 418 geometric design and, 753 –760 highway location and, 723 –730 level terrain, 387 maximum, 753 –754 multilane highways, 427– 428 rolling terrain, 387 shrinkage and, 725 –726 signalized intersections, 469 terrain and, 387, 723 –730, 754 –760 two-lane highways, 287, 392 upgrades, 392, 414 – 415 Gravel (G), 911–912 Gravity models for trip distribution, 604 – 610 Green time, determination of cycle length for, 351–352 Greenberg traffic flow model, 222, 226 –227 Greenshields traffic flow model, 220 –222, 224 –225, 1183 –1189 Ground surveys, 701–704 electronic measuring devices (EDM) for, 701–703 horizontal angle measurement for, 702 –703 level used for, 703 –704 measuring tapes used for, 704 total station for, 701–702 vertical angle measurement for, 703 Ground water, 877– 881 Group index (GI) of soil, 908 Growth factor, 610 – 613, 1038 equivalent single-axle load (ESAL) and, 1038 flexible pavement design and, 1038 trip distribution, models for, 610 – 613 Guard rail cross sections, 749 Gutters, 748 –749, 809, 812 cross sections, 748 –749 erosion control using, 812 surface drainage and, 809, 812 H Hazardous locations and elements, 177–181 critical crash rate (CRF) method for, 177–179 identification of, 177–181 potential for safety improvement (PSI) method for, 179 –181 Headwater elevations of culvert outlets, 863 – 864 Headways, 216 Hearing perception, 60 Heavy vehicle adjustment factor (fHV), 388, 413, 469 Heavy vehicle facilities, 790 –792 climbing lanes, 790 –791 emergency escape ramps, 791–792 Highway Capacity Manual (HCM), 345 –346, 365, 382 –383 Highway Capacity method for signal cycle length, 355 –360 Highway Capacity Software (HCS), 371, 1191–1200 Highway Economic Requirements System (HERS), 662 Highway location, 693 –735 bridges and, 700 –701 computer graphics for, 717–723 economic evaluation for alternatives, 695 environmental evaluation for, 695 – 696 final location survey for, 696 – 697 grades and terrain for, 723 –730 office studies for, 694 preliminary survey for, 695 – 696 plans for, 730 –732 reconnaissance survey for, 694 – 695 recreational routes, 698 scenic routes, 698 surveys for, 693 –735 urban areas of, 698 –700 Highway Performance Monitoring System (HPMS), 130, 156 Highway Safety Improvement Program (HSIP), 155 –190 See also Crashes data collection and maintenance, 155 –159 data storage and retrieval, 156 –160 engineering studies, 181, 183 –189 hazardous locations and elements, identification of, 177–181 improvement implementation and evaluation, 190 project priorities for crash avoidance, 189 Highways, –16, 39 – 47, 151–212, 237–239, 381– 456, 691– 892, 917–922 See also Freeways access control, 193 –195 alignment of, 195 capacity of, 457–547 channels for, 808 – 809, 812, 828 – 843 cross-section elements for, 745 –753 culverts for, 810 – 811, 844 – 870 drainage, 807– 892 Eisenhower (National) Interstate Highway System, 16, 44 – 45 federal support for, 11–12 federal system of, 42 – 45 funds for, 11–12, 42 – 43 geometric design of facilities, 737– 805 historical development of, –16 intercity bus transportation and, 46 level of service (LOS) of, 381– 456 location of, 693 –735 multilane, 424 – 430, 455 – 456, 746 National Highway System (NHS), 43 – 45 national plan for, 10 –11 project development process, 39 – 42 queue lengths at sections of, 237–239 safety design features, 190 –208 safety of, 151–212 shock waves due to speed reductions at sections of, 237–239 soil surveys for construction of, 917–922 surveys, 693 –735, 917–912 truck transportation and, 46 – 47 turnpikes (toll roads), –10 two-lane, 382 – 406, 436 – 451, 745 U.S Bureau of Public Roads, Hinge joints, 1082 www.EngineeringEBooksPdf.com Index Histograms, 110 –111 Home-based work (HBO), 595, 602 Horizontal alignment, 770 –790, 795 –796 bicycle paths, 795 –796 compound curves, 778 –781 field locations of, 774 –775 intersection angle (⌬) for, 773 long chord for, 773 point of curve (PC) for, 772 point of intersection (PI) for, 772 point of tangent (PT) for, 772 reverse curves, 781–783 simple curve, 771–777 spiral curves, 771, 783, 785 –786 stopping sight distance (SSD) for, 756 –761, 787–790 superelevation (a) of, 783 –787 superelevation runoff for, 783 –785 tangent runouts for, 785 –786 transition curves, 771, 783 –785 Horizontal angle measurement, 702 –703 Horizontal drains, 873 Hot-mix asphalt (HMA), 969 –989, 1003, 1058 –1061, 1064 –1070 aggregate gradation for, 969 –974 asphalt content of, 974 –975 cold-laid, 989 consensus properties of aggregate for, 1003 flexible pavement and, 1058 –1061, 1064 –1070 hot-laid, 969 –989, 1003 job-mix formula for, 974 Marshall methods for, 974 –981 Mechanistic-Empirical Pavement Design (MEPD) and, 1058 –1061, 1064 –1070 property comparison computations for, 976 –981 Hourly expansion factors (HEF), 130 –131 Housing and Urban Development (HUD), U.S Department of, 573 Human response process, 58 – 61 hearing perception, 60 perception-reaction (PIEV) time, 60 – 61 visual perception, 58 – 60 Hveem method of design, see California method of design Hveem stabilometer test, 934 –936 exudation pressure for, 934 expansion pressure for, 934 –935 resistance value (R) for, 935 –936 Hydraulic design, 827– 870 culverts, 844 – 870 open channels, 828 – 843 Hydraulic grade line (HGL), 858 Hydraulic jump in channel flow, 835 Hydrology, 813 – 827, 844 computer models for drainage simulations, 827 culverts, considerations for, 844 drainage, considerations for, 813 – 827 duration of rainfall, 813 frequency of rainfall, 813, 816 intensity of rainfall, 813 – 815 peak-flow, 820, 822, 825 – 827 rainfall and, 813 – 816 runoff, 816 – 826 unit hydrographs for, 826 – 827 Hypothesis testing for crash analysis, 165 1217 I Ice lenses, water from, 881– 883 Impedance of travel, 616 Incremental delay, 494, 496 Inductive loops, 105 Infiltration of water (qi) for drainage, 876 – 877 Information formats for digital surveys, 705 Infrastructure services, employment opportunities in, 19 –20 Inlets, 845 – 852, 866 – 870 bevel-edged, 866 – 867 configuration of, 866 – 870 control coefficients for, 848 – 849 culvert design and, 845 – 852, 866 – 870 flow control, 845 – 852 invert for, 849 – 850 submerged conditions for, 847– 849 tapered, 867– 870 types of, 845 – 846 unsubmerged conditions for, 847– 849 Institute of Transportation Engineers (ITE), 50 –51 Intercepting drains, 811 Interchanges, 265 –266, 327, 330 –332, 410 – 411, 420 – 424, 454 density (spacing), 410 – 411, 420 – 424, 454 intersections compared to, 265 –266, 327 level of service (LOS) effects from spacing between, 410 – 411 types of, 330 –332 Intercity buses, 46 Intermodal connectors, 45 Intermodal Surface Transportation Efficiency Act (ISTEA), 43 Internal rate-of-return (ROR) method of evaluation, 666 International Roughness Index (IRI), 1058 –1059, 1069 –1070 flexible pavement, 1058 –1059, 1069 –1010 JPCP pavement, 1127–1128 Intersection (volume) counts, 132 Intersection angle (⌬), 773 Intersection delay, 500 Intersection design, 200 –202, 265 –325 alignment of, 276 –277 at-grade, 265 –301 channelization of, 285 –294 curves at, 278 –285 four-leg, 271–272 interchanges and, 265 –266 multileg, 271, 273 no-control, 302 –305 pavement widths of turning roadways, 294 –301 profile (vertical alignment) of, 277–278 railroad crossings, 314 –320 safety features for, 200 –202 sight distance at, 301–314 signalized, 312 stop-controlled, 305 –309, 312 T, 267–271 traffic circles, 271–275 yield-controlled, 309 –312 Intersection summary sheets, 124 –125 Intersections, 122 –123, 200 –202, 235 –237, 265 –325, 327–380, 457–547 at-grade intersections, 265 –301 control devices for, 327–380 cordon counts, 122 design of, 200 –202, 265 –325 www.EngineeringEBooksPdf.com 1218 Index Intersections (continued) freeway ramps, 373 –377 interchanges compared to, 265 –266, 327 isolated, signal timing for, 347–362 lane groups, 344 –345, 458 queue lengths at red phase of signalized, 235 –237 railroad crossings, 314 –320 red phase of, 235 –237 saturation flow rate (s) for, 344 –345, 458 – 460, 468 – 490 shock waves at red phase of signalized, 235 –237 sight distance, 201–202, 301–314 signal timing for, 342 –372 signalized, 235 –237, 312, 457–547 volume traffic studies for, 122 –123 Interstate semitrailer design, 68 –70 Intervals for signal timing, 343, 348 –349 Interviewing method for travel time and delay studies, 139 Inventory method for parking studies, 141 ith-percentile value of speed, 101 ITS (Telematics) advanced technology, 139 J Jam density (kj), 219 Jointed Plain Concrete Pavement (JPCP), 1083, 1121–1128 International Roughness Index (IRI) for, 1127–1128 energy of subgrade deformation (DE) for, 1126 load transfer efficiency (LTE) for, 1126 mean transverse joint faulting, 1125 –1128 Mechanistic-Empirical Pavement Design (MEPD) for, 1121–1128 transverse slab cracking, 1122 –1125 Joints, 1081–1083 butt, 1083 construction, 1083 contraction, 1082 expansion, 1081–1082 hinge, 1082 rigid pavement design using, 1081–1083 K K factors for length of vertical curves, 763 –770 Kinematic characteristics of vehicles, 70 –74 Kinematic GPS surveys, 706 Kinematic viscosity test for asphalt consistency, 956 –957 Kruskal-Wallis H test for crash analysis, 165, 170 –173 L Land use analysis, 584 Lane groups, 344 –345, 458, 466 – 468, 492 – 493 critical, 492 – 493 intersection control and, 344 –345 right-turn-on-red (RTOR), 466 – 468 shared (de facto), 466 signalized intersection LOS, 458, 466 – 468 Lane utilization adjustment factor (fLu), 470, 538 Lane width, 196 –198, 390, 408 – 409, 440, 453, 469, 746 adjustment factor (fLS), 390, 440, 453, 469 cross sections for geometric design, 749 freeways, 408 – 409, 453 level of service (LOS), effects of on, 408 – 409 safety design for, 196 –198 signalized intersections, 469 travel lanes, 746 two-lane highways, 390, 440 Lanes, number of, 419, 422 – 424, 454 Lateral clearance of highways, 408 – 409, 419, 454, 456 League of American Bicyclists, 14 Least-squares network adjustment for GPS surveys, 708 Left-turn adjustment factor (fLT), 470 – 483, 538 Left-turn treatment for signal timing, 360 –361 Level of service (LOS), 34, 36 –37, 381–547, 1191–1200 adjustment factors (f ) for, 434 – 456 average travel speed (ATS), 383, 389 –392, 397– 400, 402 – 406 capacity and, 36 –37, 381–547 criteria for, 383 –387, 411– 412, 436, 451, 455, 461– 462, 535 density (D) and, 418 – 424 determination of using Highway Capacity Software (HCS), 1191–1200 directional segments, 287, 392 – 406, 438 – 439 downgrade effects on, 392, 398 – 400, 414 – 415 driver population effects on, 408, 410 free-flow speed (FFS) and, 418 – 424 freeways, 406 – 412, 418 – 424 interchange spacing, effects on, 410 – 411, 420 intersections, 457–547 lane width effects on, 408 – 409, 419 lateral clearance effects on, 408 – 409, 419, 454, 456 multilane highways, 424 – 430, 455 – 456 operation level analysis for, 382, 460 –516 passenger car equivalents (PCE) and, 408, 410, 413 – 418 percent time-spent-following (PTSF), 383, 387–389, 393 – 402 planning level analysis for, 383, 516 –527 public transportation, 36 –37 transportation value of, 34 two-lane highways, 382 – 406, 436 – 451 two-way highway segments, 387–392, 437– 439 upgrade effects on, 392, 397– 400, 414 – 415 Level terrain, 387, 743 –744 Level used for ground surveys, 703 –704 License-plate observations for travel time and delay studies, 138 Light Detection and Ranging (LiDAR) technology, 719 –721 airborne, 719 computer graphics using, 719 –721 scanner advantages of, 719 –721 software for, 721 terrestrial, 719 Lime, soil stabilization using, 1027, 1031–1032 Linear regression analysis, 223, 228 Linings for channels, 812, 828 – 829, 838 – 843 determination of, 838 – 843 erosion control and, 812, 828 types of, 829 Links, highway systems, 576 –577 Liquid limit (LL), 904 –905 Liquidity index (LI), 905 –906 Load-related cracking, 1066 Load safety factor (LSF), 1110 Load transfer efficiency (LTE), 1126 Local streets, 698, 740 –741 Log arc elasticity, 634 – 635 Long chord, 773 Long Term Pavement Performance (LTPP), 1162 Longitudinal channels, 808 – 809, 812 Longitudinal collectors, 886 – 889 www.EngineeringEBooksPdf.com Index backfill material for, 889 locations of pipes, 886 – 888 pipe diameters for, 888 subsurface systems, design of for, 886 – 889 Longitudinal (top-down) cracking, 1066 –1067, 1146 Longitudinal drains, 872 – 873 Loop closure for GPS surveys, 708 Loss coefficients for culvert outlets, 855 – 857 Loss of support (LS), 1096, 1098 Loss-on-heating test for asphalt, 966 M Macroscopic approach to traffic flow, 220 –228 application of models, 222 –223 calibration of models for, 223 –227 Greenberg model for, 222, 226 –227 Greenshields model for, 220 –222, 224 –225 regression analysis for, 223 –227 Manning’s formula for open channel flow, 829 – 834 Manual method for volume counts, 116 –117 Manual on Uniform Traffic Control Devices (MUTCD), 329 –330, 336, 371–372 Markovian model for pavement condition, 1158 –1160 Marshall methods, 974 –981 analysis of results from, 976 asphalt content in mixtures, determination of, 974 –976 property comparison computations for, 976 –981 property curves, 977 stability testing, 975 –976 Mass diagrams, 726 –729 computing ordinates of, 726 –727 interpretation of, 727–729 net accumulation from, 726 –727 Mass transit, see Public transportation Mean free speed (uf), 219 –220 Mean speed, see Average speed Mean transverse joint faulting, 1125 –1128 Measures of effectiveness, 655 – 657 Measuring tapes used for ground surveys, 704 Mechanical soil weathering, 896 Mechanistic-Empirical Pavement Design (MEPD), 1056 –1070, 1121–1128 alligator (bottom-up) cracking, 1059, 1066 criteria for, 1058 –1059 Cumulative Damage Index (DI) for, 1067–1068 energy of subgrade deformation (DE) for, 1126 evaluation of, 1060 –1070 flexible pavement, 1056 –1070 hot-mix asphalt (HMA) and, 1058 –1061, 1064 –1070 input levels for trial pavement structure, 1058 –1061 International Roughness Index (IRI) for, 1058 –1059, 1069 –1070, 1127–1129 Jointed Plain Concrete Pavement (JPCP), 1121–1128 load-related cracking, 1066 load transfer efficiency (LTE) for, 1126 longitudinal (top-down) cracking, 1066 –1067 mean transverse joint faulting, 1125 –1128 non-load-related cracking, 1068 procedure for, 1056 –1058 rigid pavement, 1121–1128 rut depth, 1059, 1061, 1064 –1066 soil characteristics for, 1062 –1063 1219 threshold values for, 1058 –1059, 1122 transverse cracking lengths, 1059 transverse slab cracking, 1122 –1125 weight-in-motion (WIM) data for, 1059 –1060 Median speed, 101 Median type adjustment factor (fM), 456 Medians, 747–748 Medium-curing (MC) asphalts, 947, 955 Merging traffic, 243 Meters, 375 –377 local (isolated), 375, 377 pretimed, 375 –376 ramp closure using, 375 –377 system-wide (coordinated), 375, 377 traffic-response, 376 –377 Metric conversion factors, 1201–1205 Metropolitan planning organization, 563 –564 MicroPAVER software model for pavement condition, 1153 Microscopic approach to traffic flow, 228 –230 Midpoint arc elasticity, 634 – 636 Minimum pedestrian volume (warrant 4), 340 Minimum radius of a curve, 85 – 88, 1203 Modal speed, 101 Mode choice, 584, 613 – 624 direct generation models for, 613 – 614 logit models for, 617– 624 modal split, 584 travel forecasting, 584, 613 – 624 trip end models for, 614 utility functions and, 617– 624 Moisture content (w) of soil, 900, 924 –926 Moisture sensitivity of superpave systems, 1019 Monthly expansion factors (MEF), 131–132 Motor Carrier Management Information System (MCMIS), 160 Mountable curbs, 286 Mountain terrain, 743 –744 Moving-vehicle technique for travel time and delay studies, 135 –138 Multilane highways, 424 – 430, 455 – 456, 746 adjustment factors (f) for, 427– 428, 456 capacity of, 424 – 430 criteria of level of service (LOS) for, 426 – 427, 455 cross section for, 746 density (D) of, 428 – 430 flow rate for, 427– 428 free-flow speed (FFS) of, 428 – 430 grade adjustments for, 427– 428 level of service (LOS) of, 424 – 430 Multileg intersections, 271, 273 Multiple regression analysis, 223 Multiple-regression prediction models for pavement condition, 1157–1158 Multiway stop signs, 334 –335 N National Cooperative Highway Research Program (NCHP), 1162 National Electronic Injury Surveillance System (NEISS), 159 National Highway System (NHS), 43 – 45 National Highway Traffic Safety Administration (NHTSA), 189 National road, 10 –11 Natural Environmental Policy Act (NEPA), 683 www.EngineeringEBooksPdf.com 1220 Index Near-optimization methods for pavement rehabilitation, 1167–1170 Neighborhood traffic circles, 272 –273 Net inflow (qn) for drainage, 883 – 884 Net present worth (NPW), 663 – 664 No passing zone adjustment factor (fnp), 389, 395, 439, 441– 444 Nodes of highway systems, 576 –577 Noise, environmental impact of, 573 Non-home-based work (NHB), 595, 602 – 603 Non-load-related cracking, 1068 Nondestructive method for soil compaction, 929 O Office studies for highway locations, 694 Off-street parking, 140, 798 – 801 Offset of signal cycle, 343 On-line positioning under service (OPUS) GPS surveys, 706 On-street parking, 140, 797–798 Open channels, see Channels Operation level analysis, 382, 460 –516 capacity and, 490 – 495 critical flow (v/c) analysis module and, 490 – 495 delays and, 494 –500 input parameters for, 462 – 466 level of service (LOS) determined from, 382, 460 –516 performance measures module for, 494 –500 saturation flow rate (s) for, 468 – 490 signalized intersections, 460 –516 Operational delay, 133 Optimization techniques for pavement rehabilitation, 1171–1172 Organic (O) soil, 911–912 Origin-destination (O-D) surveys, 581–583 Outlets, 845, 853 – 864 culvert design and, 845, 853 – 864 energy grade lines for, 858 headwater elevations of, 863 – 864 loss coefficients for, 855 – 857 types of, 853 Overhaul payments for earthmoving, 729 –730 Oversaturated queues, 254 Oversaturation, 461 Oxidation of asphalt, 950 P Pace of speed, 102 Parabolic curves, 756 –757 Parallax of aerial photographs, 714 –717 Paratransit, 36 Parking adjustment factor (fp), 469 Parking facilities, 796 – 801 angle of inclination for, 797–798 garages, 799 – 801 geometric design of, 737– 805 off-street, 798 – 801 on-street, 797–798 surface car parks, 798 –799 Parking studies, 139 –145 accumulation data for, 140 –141 analysis of data for, 144 –145 data collection for, 141–142 duration data for, 140 –142 efficiency factors for, 144 inventory method for, 141 off-street facilities, 140 on-street facilities, 140 parking demand and, 143 parking generators, identification of, 142 –143 space-hours for, 140, 144 terms for, 140 turnover data for, 140 –142 Particle sizes, 896 – 898, 1096 coarse-textured, 896, 911–912 distribution of, 896 – 898 fine-textured, 896, 911–912 organic, 911–912 peat, 911–912 rigid-pavement subbase, distribution of, 1096 soils, 896 – 898 USCS definitions for, 911–914 Particle-charge test for asphalt emulsions, 968 Passenger car equivalents (PCE), 388, 408, 410, 413 – 418, 438, 440, 446, 448 – 450, 452 – 453 freeways, 408, 410, 413 – 418, 452 – 453 RVs (ER), 388, 413 – 414, 438, 440, 446, 448 – 450 tables for, 438, 440, 446, 448 – 450 tables for, 438, 440, 446, 448 – 450, 452 – 453 trucks (ET), 388, 413 – 414, 438, 440, 446, 448 – 450 two-lane highways, 388, 438, 440, 446, 448 – 450 Passengers, 34 –36 Passing lanes, 392, 400 – 405, 450 – 451 adjustment factor (fpl), 450 – 451 two-lane highways, 392, 400 – 405 Passing sight distance, 90 –93 Passing zone combined effect adjustment factor (fd /np), 387, 437 Pavement, 294 –301, 871, 893 –1176 AASHTO design method for, 1033 –1052, 1093 –1108 asphalt, 943 –1023 bituminous materials and, 943 –1023 cement, 946, 1027, 1029 –1031, 1076 –1077 concrete, 1103, 1109 –1121 condition, 1136 –1148, 1151–1160 flexible, 1025 –1074 management of, 1133 –1176 Mechanistic-Empirical Pavement Design (MEPD) for, 1056 –1070, 1121–1128 performance, 1034 –1035, 1094 present serviceability index (PSI), 1035 rehabilitation, 1160 –1172 reliability of, 1045 –1048, 1103 rigid, 1075 –1132 serviceability performance of, 1035 skid resistance, 1148 –1151 soil engineering for, 895 –941 subsurface drainage, performance for, 871 superpave systems, 992 –1019 tests for design of, 932 –936, 953 –968 thickness of, 1093 –1108 widths of turning roadways, 294 –301 Pavement condition, 1136 –1148, 1151–1160 See also Cracking data, importance of, 1136 deterministic models for, 1152 distress, 1141–1146 family-based models for, 1152 –1157 index (PCI), 1146, 1152 –1157 www.EngineeringEBooksPdf.com Index Markovian model for, 1158 –1160 MicroPAVER software model for, 1153 multiple-regression prediction models for, 1157–1158 prediction for, 1151–1160 probabilistic models for, 1158 –1160 roughness, 1136 –1140 structural, 1146 –1148 Pavement management, 1133 –1176 approaches to, 1134 condition, 1136 –1148, 1151–1160 data, importance of, 1136 Geographic Information Systems (GIS) used for, 1172 –1174 highway rehabilitation problems, 1133 –1136 levels of, 1134 –1136 programs for, 1162 –1172 rehabilitation, 1160 –1172 roadway conditions, 1136 –1151 Pavement rehabilitation, 1160 –1172 alternatives for, 1161–1162 condition assessment for, 1163 –1165 constraints of, 1171–1172 decision variable identification, 1171 expert systems (ES) computer models for, 1162 near-optimization methods for, 1167–1170 objective function for, 1171 optimization techniques for, 1171–1172 priority assessment models for, 1165 –1170 programs for, 1162 –1172 techniques and strategies for, 1160 –1161 trigger-point ranking, 1165 –1167 Pavement roughness, 1136 –1140, 1058 –1059, 1069 –1070 International Roughness Index (IRI) for, 1058 –1059, 1069 –1070 present service index (PSI) for, 1136 –1137 present service rating (PSR) for, 1136 –1137 profilometers for, 1139 –1140 response-type equipment (meters) for, 1137–1138 Paving mixture, 969 –971, 979 maximum specific gravity of, 979 properties of, 969 –971 Peak-flow discharge (runoff), 820, 822, 825 – 827 Peak-hour factor (PHF), 344, 346 –347, 466 demand flow rate and, 466 design hourly volume (DHV) from, 344, 346 –347 intersection control and, 344, 346 –347 signalized intersection LOS, 466 Peak hour (warrant 3) traffic volume, 338 –339 Peak hour volume (PHV), 116 Peat (Pt), 911–912 Pedestrians, 62, 123, 203 –208, 483 – 488, 699 –700 characteristics of for traffic, 62 crash types and frequency for, 204 –205 occupancy (OCCpedg), 483 – 488 provisions for in urban locations, 699 –700 safety design of facilities for, 203 –208 traffic and, 62, 123 volume counts, 123 Penetration test for asphalt consistency, 958 –959 Percent time-spent-following (PTSF), 383, 387–389, 393 – 402 437– 438, 441– 442, 445 – 448 adjustment factors (f ) for, 387–389, 437– 438, 441– 442, 445 – 448 1221 directional segments, 287, 393 – 402 downgrades, 398 – 400 passing lanes, 400 – 403 two-lane highways, 383, 387–389, 393 – 402 two-way segments, 387–389 upgrades, 397– 400 Perception-reaction (PIEV) time, 60 – 61 Performance measures module, see Delay Periodic volume counts, 123 –124, 128 –132 adjustment of, 130 –132 continuous, 123 control, 123 –124 count stations, determination of number of for, 128 –130 coverage, 124 daily expansion factors (DEF) for, 131 degrees of freedom (v) for, 128 –129 hourly expansion factors (HEF) for, 130 –131 monthly expansion factors (MEF) for, 131–132 traffic studies and, 123 –124, 128 –132 Peripheral vision, 59 Permeability (K), 906 Permitted turn movements, 458 Petroleum asphalt, 944 –946 destructive (cracking) distillation of, 946 fractional (steam) distillation of, 944 –946 Phase, see Signal phase Phase relations of soils, 899 –903 degree of saturation (S), 900 –901 density (D), 901–902 moisture content (w), 900 porosity (n), 899 specific gravity, 901 three-phase principle for, 902 –903 void ratio (e), 899 –900 Photogammetry, see Aerial photographs Physical-distribution management, 19 Pipelines, freight transportation by, 34 –35 Pipes for longitudinal collectors, 886 – 888 Planning-level estimation, 569 –570 Plant mixing, 1029, 1031 Plastic limit (PL), 904 Platoon ratio (Rp), 464 – 466, 536 Pneumatic road tubes, 105 Point of curve (PC), 772 Point of intersection (PI), 772 Point of tangent (PT), 772 Point of vertical intersection (PVI), 764 –770 Points of aerial photographs, 709 –710, 712 –714 Policy committee, 563 Population and economic analysis, 584 Porosity (n) of soil, 899 Position vector for vehicles, 70 Post facto evaluations, 654 Post-processing for GPS surveys, 708 Potential for safety improvement (PSI) method for hazardous locations, 179 –181 Power (P) requirements of vehicles, 76 –78 Preemption and/or priority of vehicles, 371–372 Preliminary highway location surveys, 695 – 696 Prepared road bed, see Subgrade Present service rating (PSR), 1136 –1137 Present serviceability index (PSI), 1035, 1136 –1137 www.EngineeringEBooksPdf.com 1222 Index Present worth (PW) method of evaluation, 663 – 665 Pressure for soil tests, 934 –935 exudation, 934 expansion, 934 –935 Pretimed (fixed) traffic signals, 349 –360, 362 –365 Prime coats, 991 Principal point of aerial photographs, 709 –710 Priority assessment models for pavement rehabilitation, 1165 –1170 Probabilistic models for pavement condition, 1158 –1160 Profile for highway location, 731 Profile of at-grade intersections, 277–278 Profilometers, 1139 –1140 Progression adjustment factor (PF), 539 Progressive system for arterial signal timing, 370 –371 Proportionality test for crash analysis, 165, 168 –170 Protected-plus permitted options, uniform delay with, 497– 499 Protected turns, 458 Public transportation, 7– 8, 35 –39, 46 See also Urban transportation planning capacity, 36 –37 highways and, 46 historical development of, 7– intercity buses, 46 level of service for, 36 –37 mass transit, 36 paratransit, 36 passenger traffic by, 35 –36 ridesharing, 36 role and future of, 38 –39 urban systems, 7– Pumping of rigid pavement, 1084 –1185 Q QRS model, 616 – 617 Queues (q), 235 –239, 249 –258 arrival distribution of, 253 deterministic analysis of, 235 –250 length, characteristics of, 253 –254 number of channels of, 254 oversaturated, 254 red phase of signalized intersections, at, 235 –237 service distribution for, 254 service method for, 253 shock waves and length of, 235 –239 single-channel, undersaturated, finite, 257–258 single-channel, undersaturated, infinite, 254 –257 speed reductions at highway sections, at, 237–239 stochastic approaches to problems of, 253 –258 traffic intensity of, 255 –256 undersaturated, 254 varying demand and constant service rate causing, 252 –253 varying service rate and constant demand causing, 250 –252 R Radar-based traffic sensors (RTMS), 105 –107 Rail Carload Waybill Sample, 638 Railroad crossings, 314 –320 designs for intersections at, 314 –320 horizontal alignment of, 315 sight distance requirements for, 316 –320 stop line for, 316 –317 traffic-control devices for, 315 vertical alignment of, 315 –320 Railroads, 7, 12 –14, 28 –29, 34 –36 freight traffic by, 34 –36 historical development of, 7, 12 –14 passenger traffic by, 34 –36 selection of transportation by, 28 –29 Rainfall, 813 – 816 Ramps, 82, 373 –377, 791–792 barriers, 374 closure, 374 emergency escape, 791–792 entrance control, 373 –377 exits, 82, 373 manual barricades, 374 meters, 375 –377 stopping distance, 82 Rapid-curing (RC) asphalts, 947, 954 Rate of flow (q), 214, 218 –219 Rate per million of entering vehicles (REMV), 161–163 Rating and ranking method of evaluation, 669 – 673 Rational Factor Ranking Method (FRM), 1164 Rational method for runoff, 820 – 821 Raveling of pavement, 1146 Real-time kinematic (RTK) GPS surveys, 706 Rear stationary and forward recovery shock waves, 231–233 Receivers for GPS, 706 –707 Reconnaissance surveys, 694 – 695 Recreational routes, location of, 698 Refuge traffic islands, 286, 289 –291 Regression analysis for traffic flow, 223 –227 Regression coefficients, equations for, 1181–1182 Regulatory agencies for transportation, 48 Reinforcing steel, 1080 Remote sensing, see Aerial photographs Repeat baseline analysis for GPS surveys, 708 Research and Innovative Technology Administration (RITA), 592 Residual demand delay, 496 Residual soils, 896 Resistance value (R) of soil, 935 –936 Resistivity method for soil exploration, 918 –919 Reverse curves, 781–783 Rheological tests for asphalt, 963 Ridesharing, 36 Right-of-way, 699, 753 Right-turn adjustment factor (fRT), 470 Right-turn-on-red (RTOR), 466 – 468 Rigid pavement, 1075 –1132 aggregates for, 1078 –1080 AASHTO design method for, 1093 –1108 bending stresses in, 1085 –1087 cement (Portland) for, 1076 –1077 coarse aggregates for, 1078 concrete, 1103, 1109 –1121 Continuously Reinforced Concrete (CRCP), 1084 cracking, 1122 –1128 dowel bars for, 1081 equivalent single-axle load (ESAL), 1102 –1105 www.EngineeringEBooksPdf.com Index fine aggregates for, 1078 –1079 Jointed Plain Concrete (JPCP), 1083, 1121–1128 joints for, 1081–1083 Mechanistic-Empirical Pavement Design (MEPD) for, 1121–1128 performance, 1094 Portland Cement Association (PCA) design method for, 1109 –1121 pumping, 1084 –1185 reinforcing steel for, 1080 simply reinforced concrete, 1083 steel for, 1080 –1081 stresses in, 1085 –1093 subbase strength, 1094 subgrade strength, 1094 –1102 temperature effects on, 1090 –1093 temperature steel for, 1080 –1081 thickness design of, 1093 –1128 tie bars for, 1081 traffic effects on, 1087–1090, 1102 –1103 water requirements for, 1079 wheel load effects on, 1087–1090 Ring-and-ball softening point test for asphalts, 959 –960 Road detector methods, 105 Road mixing, 1029, 1031 Road tars, 949 Roads, 7–16, 88 –94, 153 –154, 249 –301, 689, 738 –741 See also Freeways; Highways arterial systems of, 739 –740 at-grade intersection design and, 294 –301 collector systems of, 740 –741 early building and planning of, federal support for, 11–12 geometric design of, 738 –741 local systems of, 698, 740 –741 pavement widths of turning, 294 –301 rural, 740 –741 safety-related conditions, 153 –154 sight distance for, 88 –93, 94 traffic operations, characteristics for, 88 –93 turnpikes (toll roads), –10 urban, 739 –740 Roadside barriers, 748 Roadside recovery distance, 198 –200 Roadway conditions, 1136 –1151 distress (defect) rating (DR) for, 1142, 1144 –1146 falling-load deflectometers (FWD) for, 1147–1148 pavement condition index (PCI) for, 1146 pavement distress, 1141–1146 pavement roughness, 1136 –1140 pavement structural condition, 1146 –1148 present service rating (PSR) for, 1136 –1137 present serviceability index (PSI) for, 1136 –1137 skid resistance, 1148 –1151 Roadway network (warrant 8) traffic volume, 341 Rolling resistance (Rr), 75 –76 Rolling terrain, 387, 743 –744 Rotaries, 272 Rotational viscosity test for asphalt consistency, 958 Roundabouts, 274 –275 Running time, 133 1223 Runoff, 816 – 826 antecedent moisture condition (AMC) for, 824 – 825 coefficient (C), 816 – 818 determination of for drainage, 819 – 826 flow travel time, 817– 819 peak-flow, 820, 822, 825 – 826 rational method for, 820 – 821 time of concentration for, 817 U.S Soil Conservation Service (SCS) method for, 821– 826 Rural roads, 740 –741 Rut depth, 1059, 1061, 1064 –1066 Ruts, 1146 S Safety, 151–212 accidents, 152 crashes, 152 –190 driver/operator action, 153 effectiveness of design features for, 190 –208 environmental factors, 154 highway, 151–212 Highway Safety Improvement Program (HSIP), 155 pedestrians, 203 –208 roadway condition, 153 –154 Strategic Highway Safety Plan (SHSP), 154 –190 transportation issues, 152 –154 vehicle condition, 153 Safety design features, 190 –208 access control, 193 –195 alignment of highways, 195 cross sections, 195 –200 effectiveness of, 190 –208 Guidance for Improvement of the AASHTO Strategic Highway Safety Plan, 190 –193 intersections, 200 –202 lane widening, 196 –198 objectives and strategies for, 190 –193 pedestrian facilities, 203 –208 roadside recovery distance and, 198 –200 shoulder widening, 196 –198 sight distance and, 201–202 Sag vertical curves, 756, 760 –770 Salvage value, 660 Sand (S), 911–912 Saturation (S), degree of in soil, 900 –901 Saturation flow rate (s), 344 –345, 458 – 460, 468 – 490, 537 adjustment factors (f) for, 469 – 488, 537 base equation for, 468 bicycle occupancy (OCCbicg) and, 483 – 488 conflict zones and, 483 – 484 field determination of, 488 – 490 flow ratio (v/c) for, 458 – 460 intersection control and, 344 –345 pedestrian occupancy (OCCpedg) and, 483 – 488 signalized intersection LOS, 458 – 460, 468 – 490 Saybolt Furol Viscosity test for asphalt consistency, 953 –956 Scale at points of aerial photographs, 712 –714 Scenic routes, location of, 698 School crossing (warrant 5) traffic volume, 340 Screen line (volume) counts, 122 Seals for asphalt mixtures, 990 www.EngineeringEBooksPdf.com 1224 Index Sediment control (basins), 811– 813 Seismic method for soil exploration, 919 –922 Serviceability performance of flexible pavement, 1035 Shear strength (S), 906 –907 Shock waves, 230 –243 backward forming, 231–233 backward recovery, 231–233 bottleneck conditions and, 230 –233 frontal stationary, 231–233 lengths of queues and, 235 –239 propagation of, 240 –243 queues, 235 –239, 249 –258 rear stationary and forward recovery, 231–233 red phase of signalized intersections, at, 235 –237 speed reductions at highway sections, from, 237–239 starting, 242 stopping, 242 –243 traffic streams, in, 203 –243 velocity of, 234 Shoulders, 196 –198, 291–294, 746 –747 cross sections for geometric design, 746 –747 curbed traffic islands design with, 291–294 graded, 746 safety design of, 196 –198 usable, 746 widening, 196 –198 Shrinkage limit (SL), 904 Side friction (fs), coefficients of, 87– 88 Side-tapered inlets, 867– 869 Sidewalks, 203 –208, 749 –750 cross sections for geometric design, 749 –750 safety design and, 203 –208 Sieve test for asphalt emulsions, 968 Sight distance, 81, 88 –94, 201–202, 301–314, 316 –320, 1201, 1205 all-way stop intersections, requirements for, 312 approach, 301–302 decision, 89 –90, 1205 departure, 301–302 intersection design and, 301–314 left turns, requirements for, 305 –308, 312 –313 metric conversions for equations of, 1201, 1205 no-control intersections, requirements for, 302 –305 passing, 90 –94 railroad crossings, requirements for, 316 –320 road characteristics for, 88 –94 safety design for increase of, 201–202 signalized intersections, requirements for, 312 skew effects on, 313 –314 stop-controlled intersections, requirements for, 305 –309, 312 stopping (SSD), 81, 88 –90, 1201 vehicle braking and, 81, 89 yield-controlled intersections, requirements for, 309 –312 Signal phase, 343, 361–363 plans, 361–363 signal timing and, 343, 361–363 split, 344 Signal timing, 342 –372 actuated traffic signals, 365 –368 all-red interval, 343 alternate system for, 369 –370 arterial routes, 368 –371 change and clearance interval, 343 controller for, 342 –343 critical lane group, 344 cycle length of, 343, 349 –360, 365 –368 delay of, 362 –365 design hourly volume (DHV) for, 344, 346 –347 intervals, 343, 348 –349 isolated intersections, at, 347–362 lane groups, 344 –345 left-turn treatment for, 360 –361 objectives of, 347 offset, 343 peak-hour factor (PHF) for, 344, 346 –347 phases, 343, 361–363 preemption and/or priority of vehicles and, 371–372 pretimed (fixed) traffic signals, 349 –360, 362 –365 progressive system for, 370 –371 saturation flow rate (s) for, 344 –345 simultaneous system for, 368 –369 split phase, 344 yellow interval, 348 –349 Signalized conditions, 458, 466 Signalized intersections, 235 –237, 312, 457–547 arrival types (AT) for, 464 – 466, 536 capacity at, 457–547 conflict zones, 483 – 487 criteria for level of service (LOS), 461– 462, 535 demand flow rate, 466 – 468 geometric condition records for, 458, 462, 465 lane grouping, 458, 466 – 468 level of service (LOS) of, 457–547 operation level analysis for, 460 –516 peak hour factor (PHF) for, 466 planning level analysis for, 516 –527 platoon ratio (Rp) for, 464 – 466, 536 queue lengths at, 235 –237 red phase, 235 –237 right-turn-on-red (RTOR), 466 – 468 saturation flow rate (s) for, 458 – 460, 468 – 490 shock waves at , 235 –237 sight distance requirements for, 312 signalized conditions, 458, 466 traffic condition records for, 463 – 466 Silt (M), 911–912 Silt fence, 813 Simple horizontal curves, 771–777 Simply reinforced concrete pavement, 1083 Simultaneous system for arterial signal timing, 368 –369 Single unit (SU) truck design, 68, 70 Situation definition for transportation planning, 552 –554 Six-year improvement program (SYIP), 39 – 42 Skew effects on sight distance, 313 –314 Skid marks, braking and velocity estimation from, 83 – 85 Skid resistance, 1148 –1151 Skim tree, 625 Slope drains, 813 Slope-tapered inlets, 869 – 870 Slopes, 750 –753, 808, 812, 871 cross sections, 750 –753 longitudinal, 808 side, 752 –753 subsurface drainage, stability for, 871 www.EngineeringEBooksPdf.com Index surface drainage, 808, 812 transverse (cross), 750 –752, 808 Slow-curing (SC) asphalts, 947 Slurry seal, 990 Smoothness, see International Roughness Index (IRI) Social impact of transportation, 682 – 683 Soil, 895 –941, 1062 –1063 AASHTO classification system for, 908 –910 Atterberg limits for, 904 –907 classification of for highway use, 907–917 coarse-textured, 896, 911–912 compaction, 922 –937 engineering for highway design, 895 –941 fine-textured, 896, 911–912 flexible pavement, characteristics of for, 1062 –1063 frost action in, 936 –937 group index (GI) of, 908 origin and formation of, 896 particle sizes of, 896 – 898 phase relations of, 899 –903 residual, 896 resistivity method for, 918 –919 seismic method for, 919 –922 surface texture of, 896 – 898 surveys of for highway construction, 917–922 tests for pavement design, 932 –936 transported, 896 Unified Soil Classification System (USCS), 910 –917 wave velocities for, 920 weathering, 895 – 896 Soil compaction, 922 –937 compacting equipment for, 929 –932 destructive methods for, 928 –929 effect of compacting effort, 924 –925 embankment formation and control, 927–928 field procedures for, 927–932 moisture content (w), optimum for, 924 –926 nondestructive method for, 929 spreading equipment for, 929 Soil stabilization, 1027–1032 asphalt, 1027, 1031 cement, 1027, 1029 –1031 flexible pavement, 1027–1032 lime, 1027, 1031–1032 pulverizing soil for, 1029 purposes of, 1028 Soil tests for pavement design, 932 –936 California Bearing Ratio (CBR) test, 932 –934 Hveem stabilometer test, 934 –936 Solubility test for asphalt, 966 Space headway (d), 216 Space-hours for parking, 140, 144 Space lag in traffic, 244 Space mean speed, 215 –216 Spalls, see Cracking Specific gravity, 901, 964 –965, 976 –979 aggregates, 976 –978 apparent, 977–978 asphalt, 964 –965, 976 –979 bulk, 976 effective, 978 maximum, 979 1225 paving mixtures, 979 soil, 901 test for asphalt, 964 –965 Speed (u), 101–102, 114 –115, 214 –216, 219 –220, 743 –745, 795 See also Average speed; Average travel speed (ATS) average (mean) speed, 101 bicycle path design, 795 design, 743 –745, 795 determination of, 214 –215 geometric highway design and, 743 –745 mean free (uf), 219-220 median, 101, 114 –115 modal, 101 pace of, 102 space mean, 215 –216 spot speed studies, rates for, 101–102, 114 –115 standard deviation of, 102 –104, 114 –115 terrain and, 743 –745 time mean, 215 traffic flow and, 214 –216 Spiral curves, 771, 783, 785 –786, 1203 Splines, 696 Split phase of signal timing, 344 Spot speed studies, 100 –115 autoscopes for, 106 –108 cumulative distribution for, 112 –113 data presentation and analysis for, 109 –114 duration of, 100 –101 electronic-principle detectors for, 106 –108 frequency distribution for, 110 –112 histograms for, 110 –111 inductive loops for, 105 ith-percentile value for, 101 locations for, 100 pneumatic road tubes for, 105 radar-based traffic sensors (RTMS) for, 105 –107 road detector methods for, 105 samples for, 101–105 speed rates for, 101–102, 114 –115 standard deviation of speed for, 102 –104, 114 –115 time of day of, 100 –101 Stability of asphalt mixtures, 975 –982 evaluation and adjustments for, 981–982 test for, 975 –981 voids and, 982 Stakeholders, identification of for projects, 654 – 655 Standard deviation of speed, 102 –104, 114 –115 difference of means of, 114 –115 normal distribution of, 102 –104 spot speed studies and, 102 –115 State transportation improvement program (STIP), 566 Static characteristics of vehicles, 63 –70 Static GPS surveys, 706 Steamboats, historical use of, 12 –14 Steel for rigid-pavement design, 1080 –1081 dowel bars, 1081 reinforcing, 1080 temperature, 1080 –1081 tie bars, 1081 Stereoplotters (stereoscopes), 710 –711 Stereoscopy, 710 –712 Stop-controlled intersections, 305 –309, 312 www.EngineeringEBooksPdf.com 1226 Index Stop signs, 334 Stopped-time delay, 133 Stopping sight distance (SSD), 81, 88 –90, 756 –761, 787–790, 1201 alignment of highways using, 756 –761, 787–790 curve radii based on, 787–790 horizontal alignment, 787–790 metric formula for, 1201 road characteristics for, 88 –90 vertical alignment, 756 –761 Strategic Highway Networks (STRAHNET), 45 Strategic Highway Research Program (SHRP), 992 –993, 1162 Strategic Highway Safety Plan (SHSP), 154 –190 Streetcars, history of, 14 –15 Streets, see Roads Stress distribution of flexible pavement, 1032 –1033 Stresses in rigid pavement, 1085 –1093 bending, 1085 –1087 traffic wheel loads, due to, 1087–1090 temperature effects, due to, 1090 –1093 Structural number (SN) for flexible pavement, 1047–1052 Subbase course, 1026, 1040 –1041, 1094, 1096, 1109 concrete pavement, 1109 flexible pavement, 1026 materials for, 1040 –1041, 1109 particle size distribution for, 1096 rigid pavement, 1094, 1096 strength of, 1094 Subgrade, 1026, 1040, 1094 –1102, 1109 –1110 concrete pavement, 1109 –1110 flexible pavement, 1026 loss of support (LS), 1096, 1098 materials for, 1040 rigid pavement, 1094 –1102 strength of, 1094 –1102 Westergaard modulus for, 1109 –1110 Submerged soil density (gЈ), 901 Subsurface drainage, 807, 870 – 889 blankets, 873 – 875 design of, 875 – 889 drains, 811, 872 – 874 economic analysis for, 889 filter requirements for, 886 ground water, 877– 881 highway systems for, 871– 875 ice lenses, water from, 881– 883 inadequate subdrainage, effects of, 870 – 871 infiltration of water (qi) for, 876 – 877 layer design, 884 – 886 longitudinal collectors, 886 – 889 net inflow (qn) for, 883 – 884 pavement performance for, 871 slope stability for, 871 transmissibility, coefficient of, 884 – 885 vertical outflow (qv) for, 883 well systems, 874 Summary tables for traffic volume data, 124, 128 Sunk costs, 660 Superelevation (a), 85 – 86, 783 –787 attainment of, 786 –787 horizontal alignment and, 783 –787 rate of, 85 – 86 runoff (Lr), 783 –785 Superpave systems, 992 –1019 aggregate for, 1003 –1008 asphalt binders for, 993 –1002, 1017 gradation of aggregates for, 1005 –1008 moisture sensitivity of, 1019 selection of materials for, 993 –1008 volumetric trial mixture design, 1008 –1019 Supply-chain management, 17 Surface area of asphalt, 951 Surface course, flexible pavement, 1026 –1027 Surface drainage, 807– 813, 827– 870 bridges, 809 – 810 culverts, 810 – 811, 844 – 870 erosion control, 811– 813 highway structures for, 809 – 811, 827– 870 hydraulic designs for, 827– 870 longitudinal channels, 808 – 809 longitudinal slopes, 808 sediment control, 811– 813 transverse slopes, 808 Surface texture of soil, 896 – 898 Surface Transportation Efficiency Analysis Module (STEAM), 585 Surface treatments for asphalt mixtures, 991–992 Surveys, 693 –735, 917–922 aerial photographs for, 708 –718 computer graphics, 717–723 curve templates for, 696 – 697 digital, 704 –708 economic evaluation for alternatives, 695 environmental evaluation for, 695 – 696 final highway location, 696 – 697 geophysical methods of soil exploration, 917–922 Global Positioning Systems (GPS) for, 705 –708 ground, 701–704 highway location and, 693 –735 preliminary, 695 – 696 reconnaissance, 694 – 695 remote sensing for, 708 –717 resistivity method for soil exploration, 918 –919 seismic method for soil exploration, 919 –922 soil, highway construction and, 917–922 splines for, 696 System inventories, 576 –579 computerized networks for, 576 –579 existing travel and facilities, 568 travel forecasting, 576 –579 urban transportation planning, 568 T T intersections, 267–271 t-test for crash analysis, 165 –168 Tack coats, 991 Tailwater, 844 – 845 Tangent runouts, 785 –786 Tapered inlets, 867– 870 Technical committee, 563 Temperature effects, 950 –952, 966, 1090 –1093 asphalt, 950 –952, 966 loss-on-heating test for, 966 rigid pavements, 1090 –1093 Temperature steel, 1080 –1081 www.EngineeringEBooksPdf.com Index Terrain, 387, 723 –730, 743 –745, 754 –760 alignment of highways and, 754 –760 design speed and, 743 –745 earthwork and, 723 –730 geometric design and, 743 –745, 754 –760 grades and, 387, 723 –730, 754 –760 level, 387, 743 –744 mountain, 743 –744 rolling, 387, 743 –744 Terrestrial Light Detection and Ranging (LiDAR), 719 Test vehicle methods for travel time and delay studies, 134 –138 Thin-film oven (TFO) test for asphalts, 960 –961 3C process (continuing, comprehensive, and cooperative), 562 Tie bars, 1081 Time-based distribution charts, 124, 127 Time headway (h), 216 Time lag in traffic, 244 Time mean speed, 215 –216 Time-space diagrams, 213 –214 Toll roads, –10 Total control delay, 496 – 497 Total lost time method for signal cycle length, 350 Total soil density (g), 901–902 Total station, 701–702 Trade associations for transportation, 50 Trade-off approaches for evaluation, 678 – 679 Traffic, 20, 34 –36, 55 –547, 1000 –1002, 1035 –1040, 1087–1090, 1102 –1103, 1109 –1110 asphalt binder grades, speed and loading considerations for, 1000 –1002 bicyclist characteristics for, 62 – 63 capacity, 381–547 characteristics of, 57–98 concrete pavement, 1109 –1110 control devices, 327–380 driver characteristics, 58 – 62 employment opportunities for, 20 engineering studies for, 99 –150 equivalent single-axle loads (ESAL), 1000, 1035 –1040, 1102 –1105 flexible pavement design and, 1035 –1040 flow, 213 –263 freeways, 373 –377, 406 – 424 freight, 34 –36 highways, 151–212, 237–239, 381– 456 intersections, 122 –123, 200 –202, 235 –237, 265 –325, 327–380, 457–547 level of service (LOS), 381–547 load determination for pavement design, 1035 –1040, 1102, 1109 –1110 load safety factor (LSF) for, 1110 management of, 20 modes of transportation for, 34 –36 multilane highways, 424 – 430 operations, 20, 55 –547 passengers, 34 –36 pedestrian characteristics for, 62 perception-reaction process, 60 – 61 professions for, 20 rigid pavement design and, 1087–1090, 1102 –1103, 1109 –1110 road characteristics for, 88 –93 safety, 151–212 sight distance, 81, 88 –93 stresses due to, 1087–1090 two-lane highways, 382 – 406, 436 – 451 vehicle characteristics for, 63 – 88 wheel loads, stresses due to, 1087–1090 Traffic analysis zones (TAZ), 568, 574 –575, 592 districts as, 592 intercity travel forecasting, 592 urban travel forecasting, 547–575 Traffic assignment, 584, 625 – 633 capacity restraint for, 629 – 631 diversion curves for, 625 – 626 minimum path algorithm for, 625 – 629 total system cost for, 632 – 633 travel forecasting, 584, 625 – 633 Traffic circles, 271–275 design of, 271–275 neighborhood, 272 –273 rotaries, 272 roundabouts, 274 –275 Traffic condition records, 463 – 466 Traffic engineering studies, 99 –150, 181, 183 –189 Automated Data Processing (ADP) systems, 99 crashes, 181, 183 –189 parking, 139 –145 spot speed studies, 100 –115 Strategic Highway Safety Plan (SHSP), 181, 183 –189 travel time and delay, 133 –139 volume studies, 115 –132 Traffic flow, 124 –125, 213 –263, 413 bottleneck conditions, 230 –233 density, 214, 218 –219 diverging, 243 flow-density relationships of, 218 –219 freeways, 413 fundamental diagram of, 219 –220 gaps and gap acceptance, 244 –249 Greenberg model for, 222, 226 –227 Greenshields model for, 220 –222, 224 –225 macroscopic approach for, 220 –228 maps, 124 –125 mathematical relationships for, 220 –230 merging, 243 microscopic approach for, 228 –230 passenger cars, 413 queues, 235 –239, 249 –258 rate of flow, 214, 218 –219, 413 shock waves in, 230 –243 space headway, 216 space lag, 244 speed, 214 –216 stochastic approaches to problems of, 247–249, 253 –258 time headway, 216 time lag, 244 time-space diagrams, 213 –214 weaving, 243 –244 Traffic index (TI), 1053 Traffic intensity of queues, 255 –256 Traffic islands, 285 –294 approach ends for, 291–294 at-grade intersection design and, 285 –294 www.EngineeringEBooksPdf.com 1227 1228 Index Traffic islands (continued) channelization and, 285 –294 channelized, 286 –288 curbed, 286, 291–294 divisional, 286, 289 flushed, 256 pavement edges forming, 286 pavement markings forming, 286 refuge, 286, 289 –291 shoulders and, 291–294 Traffic signals, 335 –372 actuated, 365 –368 coordinated signal system (warrant 6), 340 crash experience (warrant 7), 340 cycle length of, 343, 349 –360, 365 –368 eight-hour vehicle volume (warrant 1), 336 –337 four-hour vehicle volume (warrant 2), 337–338 fully actuated, 368 minimum pedestrian volume (warrant 4), 340 peak hour (warrant 3), 338 –339 pretimed (fixed), 349 –360 roadway network (warrant 8), 341 school crossing (warrant 5), 340 semiactuated, 366 –367 signal timing, 342 –372 warrants, 336 –342 Transition curves, 771, 783 –785 Transmissibility, coefficient of for drainage, 884 – 885 Transportation, 1–26, 27–54 automobiles, 8, 14 –15, 28 –29 aviation, 8, 28 –29, 34 –36 benefits of, –5, 28 –32 canals, 7, 10 costs, –5, 30 –33, 42 – 43 economic growth and, employment opportunities in, 16 –23 engineering profession, 18 –23 freight traffic, 34 –36 highways, –16, 39 – 47 history of, –16 importance of, – infrastructure services, 19 –20 level of service for, 34, 36 –37 logistics, 17 modes of, 28 –29, 34 – 47 organizations for, 47–51 passenger traffic, 34 –36 pipelines, 34 –35 public, 7– 8, 35 –39, 46 railroads, 7, 12 –14, 28 –29, 34 –36 roads, 7–16 selection of, 28 –29 supply-chain management, 17 systems, 27–33 trucks, 34 –36, 46 – 47 United States, in, – vehicle design, 17–18 water, 7, 10, 12 –14 Transportation engineering, see Engineering profession Transportation improvement program (TIP), 566, 585 Transportation planning, 549 – 689, 698 –700 See also Highway location coordination of system locations, 699 evaluation of alternatives, 555 –556, 570 –573, 653 – 689 implementation processes for, 564 –566 institutions for structure of, 562 –566 local street connections, 698 performance analysis, 555 problem definition, 554 process of, 551–589 project selection, 556 right-of-way acquisition, 699 search for solutions, 554 situation definition, 552 –554 specification and construction, 556 3C process (continuing, comprehensive, and cooperative), 562 traffic analysis zones (TAZ) for, 568, 574 –575 travel demand, 555, 571–589, 591– 652 travel forecasting, 574 –586, 591– 652 urban, 566 –586, 699 –700 Transportation Research Board (TRB), 5, 51, 190 –193 Transported soils, 896 Transverse cracking, 1122 –1128 joint spalling, 1128 mean joint faulting, 1125 –1128 slabs, 1122 –1125 Transverse drains, 873 – 874 Travel demand, 569 –586, 591– 652 estimation of costs and, 569 –571 factors influencing, 592 forecasting, 574 –586, 591–593 intercity travel, 555, 591– 652 urban transportation planning, 566 –574 Travel demand forecasting, 574 –586, 591– 652 calibration for, 583 –584, 604 – 608, 622 – 624 commodity flow data for, 637– 638 data collection for, 576 demand, 591– 652 districts for travel demand, 592 elasticity of demand, 633 – 635 freight demand, 637– 638 freight planning, 585 –586 Geographic Information Systems (GIS) for, 579 –581 intercity travel, 591– 652 mode choice (split), 584, 613 – 624 origin-destination (O-D) surveys for, 581–583 population and economic data for, 576 steps for process of, 584 –585 steps for travel demand, 592 –593 system inventories for, 576 –579 traffic analysis zones (TAZ), 574 –575 traffic assignment, 584, 625 – 633 travel impact studies for, 638 – 644 travel surveys for, 581–583, 622 – 624 trend analysis, 633, 637 trip distribution, 584, 603 – 613 trip generation, 584, 593 – 603 urban transportation planning, 574 –586 Travel impact studies, 638 – 644 Travel surveys, 581–583, 622 – 624 www.EngineeringEBooksPdf.com Index Travel time and delay studies, 133 –139 applications of data from, 133 average-speed technique for, 134 –135 floating-car technique for, 134 interviewing method for, 139 ITS (Telematics) advanced technology for, 139 license-plate observations for, 138 moving-vehicle technique for, 135 –138 terms for, 133 test vehicle methods for, 134 –138 Travel time costs, 661– 662 Traverse cracking, 1059, 1146 lengths of, 1059 Pavement Condition Index (PCI) for, 1146 Trend analysis, 633, 637 Triangulated Irregular Network (TIN) files, 705 Trigger-point ranking, 1165 –1167 Trip distribution, 584, 603 – 613 calibration for, 604 – 608 gravity models for, 604 – 610 growth factor models for, 610 – 613 travel forecasting, 584, 603 – 613 Trip ends, 593 Trip generation, 584, 593 – 603 balancing trip productions and attractions for, 602 – 603 cross-classification for, 594 – 600 home-based work (HBO), 595, 602 non-home-based work (NHB), 595, 602 – 603 rates based on activity units, 600 – 602 travel forecasting, 584, 593 – 603 Trucks, 34 –36, 46 – 47, 63 –70, 790 –792 design, 63 –70 freight traffic by, 34 –36 facilities for heavy vehicles, 790 –792 highways and, 46 interstate semitrailer, 68 –70 single unit (SU), 68, 70 Turnover data for parking studies, 140 –142 Turnpikes, history of, –10 Two-lane highways, 382 – 406, 436 – 451, 745 adjustment factors (f) for, 387–390, 437– 451 average travel speed (ATS), 383, 389 –392, 397– 400, 402 – 406 base free-flow speed (BFFS), 390 capacity of, 383 – 406 classification of, 382 criteria for level of service (LOS), 383 –387, 436 cross section for, 745 directional segments, 287, 392 – 406 downgrades, 392 , 398 – 400 extended segments, 392 level of service and, 382 – 406, 436 – 451 level terrain, 387 operation level analysis for, 382 passing lanes, 392, 400 – 405 percent time-spent-following (PTSF), 383, 387–389, 393 – 402 planning level analysis for, 383 rolling terrain, 387 two-way segments, 387–392 upgrades, 392, 397– 400 vehicle miles traveled (VMT), 391–392 1229 U U.S Bureau of Public Roads, U.S Department of Transportation (DOT), 49 U.S Geological Survey, 827 U.S Soil Conservation Service (SCS) method for runoff, 821– 826 Undersaturated queues, 254 Unified Soil Classification System (USCS), 910 –917 Uniform delay, 494, 497– 499 Uniform speed limits (USL), 170 Unit hydrographs, 826 – 827 Upgrades, 392, 397– 400, 414 – 415 freeways, 414 – 415 level of service and, 392, 397– 400, 414 – 415 two-lane highways, 392, 397– 400 Upstream storage of culverts, 845 Urban roads, 739 –740 Urban Storm Drainage Model, 827 Urban transportation planning, 566 –586, 698 –700 See also Public transportation bicyclist provisions, 699 –700 coordination of systems, 699 cost estimation, 569 –570 establishment of goals and objectives, 568 evaluation of alternatives, 570 –573 generation of alternatives, 568 highway locations, 698 –700 inventory of existing travel and facilities, 568 local street connections, 698 long-term projects for, 566 –567 pedestrian provisions, 699 –700 project selection, 573 –574 right-of-way acquisition, 699 short-term projects for, 566 –567 travel demand estimation, 569 –571 travel forecasting, 574 –586 Urban Transportation Planning System (UTPS), 584 Urban travel factor (UTF), 615 Utility functions, 617– 624 borrowing from other sources, 619 – 621 calibrating survey data, 622 – 624 logit models and, 617– 624 service parameter changes, modifications of for, 621– 622 V Vehicle classification (VC), 116 Vehicle Inventory and Use Survey (VIUS), 638 Vehicle miles traveled (VMT), 116, 151, 391–392 Vehicles, 17–18, 34 –36, 63 – 88, 153, 371–372, 408, 410, 413 – 418, 661, 745 See also Automobiles; Trucks acceleration (a) of, 70 –74 air resistance (Ra), 74 average speed for, 418 – 424 braking distance (Db), 78 – 85 circular curves and, 85 – 88 curve resistance (Rc), 76 design, 63 – 88, 745 dimension classifications for, 66 – 68 dynamic characteristics of, 74 – 88 equivalence values, 408, 410, 413 – 418 emergency, 371–372 www.EngineeringEBooksPdf.com 1230 Index Vehicles (continued) employment opportunities pertaining to, 17–18 federal regulations for, 64 –70 freight traffic from, 34 –36 grade resistance, 74 –75 gross weight for, 64 – 65 kinematic characteristics of, 70 –74 level of service (LOS), effects of from, 408, 410, 413 – 418 operating costs, 661 passenger equivalent (PCE) values, 413 – 418 passenger traffic from, 34 –36 position vector for, 70 power (P) requirements, 76 –78 preemption and/or priority of at signals, 371–372 rolling resistance (Rr), 75 –76 safety-related conditions, 153 static characteristics of, 63 –70 traffic operations, characteristics for, 63 – 88 trucks, 34 –36, 46 – 47, 63 –70 velocity (u) of, 70 Velocity (u), 70 –74, 83 – 85, 234 acceleration (a) as a function of, 71–74 braking distance (Db) and, 83 – 85 shock waves, 234 skid mark estimation of, 83 – 85 vehicle estimation of, 70 Vertex (V), 772 Vertical aerial photographs, 712 –714 Vertical alignment, 277–278, 756 –770, 796 –797, 1204 appearance criterion for, 761 at-grade intersections, 277–278 beginning of curve (BVC) for, 764 –770 bicycle paths, 796 –797 comfort criterion for, 761 crest curves, 756 –760, 763 –770 design procedure for curves, 767–770 drainage criterion for, 761–762 elevations of curves, 764 –767 end of curve (EVC) for, 764 –770 K factors for, 763 –770 length of curves for, 756 –770, 1204 parabolic curves for, 756 –757 point of intersection (PVI) for, 764 –770 sag curves, 756, 760 –770 stopping sight distance (SSD) for, 756 –761 Vertical angle measurement, 703 Vertical outflow (qv) for drainage, 883 Visual perception, 58-60 Void ratio (e) of soil, 899 –900 Voids, 980 –982 air, percent of in compacted asphalt mixtures, 980 –981 asphalt stability, adjustment of for, 981–982 percent of in compacted mineral aggregates (VMA), 980 Volatilization of asphalt, 950, 966 Volume traffic studies, 115 –132 adjustment of periodic counts for, 128 –132 automatic method for volume counts, 117–121 average annual daily traffic (AADT), 115, 132 average daily traffic (ADT), 115 characteristics of, 126 –128 cordon counts, 122 data presentation for, 124 –126 expansion factors for, 130 –132 intersection counts, 132 intersection summary sheets for, 124 –125 manual method for volume counts, 116 –117 peak hour volume (PHV), 116 pedestrian counts, 123 periodic counts, 123 –124, 128 –132 screen line counts, 122 summary tables for, 124, 128 time-based distribution charts for, 124, 127 traffic flow maps for, 124 –125 vehicle classification (VC), 116 vehicle miles of travel (VMT), 116 Volumetric trial mixture design, 1008 –1019 aggregate structure for, 1009 –1011 asphalt binder for, 1009 –1010, 1017–1018 dust percentage for, 1016 evaluation of, 1011–1016 moisture sensitivity of, 1019 percentage of asphalt binder in, 1009 –1001 W Warrants for traffic volume, 336 –342 Water content test for asphalt, 967 Water requirements for rigid pavement design, 1079 Water resistance of asphalt, 952 Water Surface Profile (WSPRO), 827 Water transportation, 7, 10, 12 –14 canals, 7, 10 historical development of, 7, 10, 12 –14 steamboats, 12 –14 Wave velocities for soils, 920 Weathering, 895 – 896, 950 –951, 960 –961 asphalt, 950 –951, 960 –961 durability tests, 960 –961 oxidation and, 950 soil, 895 – 896 surface area and, 951 temperature and, 951 volatilization and, 950 Weaving traffic, 243 –244 Webster delay model, 362 –365 Webster method for signal cycle length, 350, 352 –355 Weight-in-motion (WIM) data, 1059 –1060 Well systems, 874 Westergaard modulus, 1109 –1110 Wheel loads, stresses due to, 1087–1090 Women’s Transportation Seminar (WTS), 50 Y Yellow interval, 348 –349 Yield signs, 333 Yield-controlled intersections, 309 –312 www.EngineeringEBooksPdf.com ... ($1000s) Autos per Household 10 11 12 13 14 15 16 17 18 19 20 10 5 15 13 11 10 11 12 8 16 24 68 44 18 68 38 36 28 76 72 32 28 44 44 52 60 44 52 28 0 1 1 2 2 1 Step Step parentheses is the percentage... 1.58 26 20 4350 825 73 High Slight Some 30 3.8 7.6 55 3.7 4.0 2. 5 1.18 25 20 4180 536 73 Moderate 25 Much 0.6 1.54 125 0 20 75 386 70 Slight 28 Much 560 Part Transportation Planning Table 11 .2 Ranking... Income ($1000s) 2? ? Total 24 24 –36 36 – 48 48 – 60 Ͼ60 Total 2( 67) 1 (25 ) 1 (20 ) — — 1(33) 3(50) 2( 40) 1(33) 1 (25 ) 0(0) 1 (25 ) 2( 40) 2( 67) 3(75) 3(100) 5(100) 5(100) 3(100) 4(100) 20 Values in parentheses