The Man-Made Environment: Transportation Transportation factors such as traffic and parking always should be considered in the preparation of a NEPA statement. In some cases, the existing transportation and the impacts upon it may be major factors in the study, for example, large buildings and facilities in urban areas. In others, transportation issues may be relatively minor. The basic points to be considered include answers to the following questions: • Are there adequate transportation and parking modes presently in existence to bring workers to the project site? • What will be the effects on existing transportation systems? • Will new transportation facilities be required? The discussion should focus on the effects on such things as public transit sys- tems capacities and constraints, vehicular congestion, capacity of existing roads, safety considerations, adequacy of parking, and so on. A new project can impact transportation systems in several ways: • Construction and operation may place increased and perhaps unattainable demands on existing transportation systems. • Operation may generate a demand for new facilities (e.g., noise barriers, parking facilities, etc.). • Construction and operation may permanently displace certain transporta- tion routes. • Location and operation of the project may reduce transportation accessibil- ity and access to other facilities and services. To evaluate these potential impacts, a number of techniques are used to quantify existing levels of service and to document impacts which might result from the con- struction of the proposed project. Typically, the starting point is an inventory of the situation in the proposed study area, including roads, public transportation, and park- ing facilities. These inventories are completed through a review of community maps and plans, capital improvements budgets, interviews with local officials, field sur- veys, and contacts with state, regional, and local agencies. The inventory then is compared to accepted national or local standards for lev- els of service to determine existing capacity. Future expansion plans are evaluated in comparison to these standards to determine future capacity levels. After the land-use 13 © 1999 by CRC Press LLC and population projections are completed for the no action and action alternative pro- posals, the impacts on transportation are documented in comparison to these future capacity levels. Nearly every EIS requires some consideration of transportation. Invariably, an impact of some type is anticipated, its significance depending on the nature and mag- nitude of construction, the level of induced growth, the location of the project, and other site-specific factors. In the detailed discussion, the entire range of transportation facilities that would be available to the staff and visitors of the project should be described in terms of transit modes, frequency of service, and commuter patterns for employment. The EIS author also should research street and highway improvement plans affecting the alter- native sites; projected road capacity vs. design capacity; traffic counts on major arter- ies; and the nearest commercial air, rail, and bus services. Data generally are collected from the U.S. Department of Transportation and the similar state agencies. Because of the importance of this factor in the selection of a site, particular atten- tion should be given to the following items: • Local traffic considerations: Maps may be drawn showing major traffic arteries near each site, with emphasis on peak hour traffic volumes. The number and adequacy of parking spaces also should be indicated. • Transit access: Present and planned bus routes should be described and mapped; other public mass transit systems are examined thoroughly; pos- sible carpools for employees are considered. • Pedestrian access: The pedestrian access to each site should be examined with emphasis on convenience and safety. • Traffic analysis: Projected levels of traffic resulting from the project are determined and compared to the existing capacity of the transportation sys- tems. Other potential transportation problems relating to increased fre- quency, higher accident potential, and the transport of hazardous materials are also identified through this analysis. 13.1 EIS EXAMPLE As an example of the type of material in an EIS where transportation is a major fac- tor, the next several pages present an excerpt from the Environmental Assessment on the rehabilitation of Union Station, Washington, D.C. (BREGMAN & COMPANY, 1985). The factors considered here such as public transit, traffic flow, parking for taxis and automobiles, as well as construction and operation impacts are illustrative of the considerations that must be given to transportation. “Transportation and Circulation Union Station is well served by Washington, D.C.’s transportation system. Two broad diagonal streets, Massachusetts and Louisiana Avenues, converge on the site, while three more major arterials, North Capitol Street, Constitution Avenue, and Delaware Avenue, pass nearby. The freeway system is within three blocks of Union Station. The eight year old rapid transit system (Metro) has a station within Union Station with lines © 1999 by CRC Press LLC extending directly to Silver Spring and Shady Grove in Montgomery County, Maryland and with transfer service to Prince George’s County, Maryland, and Alexandria, Arlington County, and Fairfax County in Virginia. Metro provides excellent access throughout the D.C. area. Of primary importance to Union Station are the arterial streets which provide direct access. Massachusetts and Louisiana Avenues lead to Columbus Plaza in front of the Station. H and E Streets also provide direct access and they, along with Massachusetts Avenue, connect the site with ramps to and from the Center Leg freeway. H Street provides the primary access to the parking garage behind the Station. Metrobus routes M2, X8, 11M, and 40, terminate in the garage, with direct trans- fers to Metrorail below. Additional Metrobus routes that serve Union Station are D2, D4, D6, D8, 42, 44, 91, 92 and X1. Traffic Flow The most recent environmental assessment of Union Station (1) analyzed the impact of the Union Station bus/parking garage and southeast ramp on traffic and transportation systems involving the arterial approaches to Union Station. It addressed the transporta- tion and circulation impacts associated with a fully utilized garage of 1295 spaces. That assessment concluded that parking garage-generated traffic growth would have no sig- nificant impact on traffic or other aspects of transportation systems. Much of the follow- ing discussion is derived from that report, supplemented with an analysis of the additional impacts projected to result from the proposed project to rehabilitate Union Station. Levels-of-service on local streets are generally acceptable with only one key north–south arterial, North Capitol Street, experiencing a poor level of service. Recent levels of service at major intersections in the evening peak hour, as reported in the 1982 Federal Highway Administration’s environmental assessment (1), are shown in the next table. Six levels of traffic service are possible, A through F. They are used to define the traf- fic flow at each intersection. Level A can be characterized as free flow, with little conges- tion and high maneuverability. Level B indicates little congestion although traffic may be moderately heavy. Level C implies heavy traffic without significant delays. Level D indi- cates unstable flow and significant delays. Level E is characterized by operation at full capacity, and motorists at signals often have to wait through several red lights. Finally, Level F implies forced flow with heavy queuing of vehicles with frequent stoppages. Existing Traffic Levels-of-Service at Major Intersections Intersection Approach From Level-of-Service North Capitol and North B Massachusetts Avenue, N.W. South C West B East A North Capitol and North C H Streets, N.W. South D West C/D East B Third and H North A Streets, N.W. South A West A East A Source: 1982 Federal Highway Administration environmental assessment. © 1999 by CRC Press LLC The 1982 environmental assessment conducted by Sverdrup and Parcel shows the projected average daily traffic volumes for Union Station area roadways in 1990. Roadway volumes were projected to remain at 1980 levels under the assumption that programmed expansion of Metrorail would continue to absorb any additional demand resulting from development near Union Station. A comparison of the existing and future levels-of-service at the major intersections in the Union Station area indicated that the garage/ramp project would not have an impact sufficient to change the levels-of-service which are in most cases reasonably good for peak hour traffic. An analysis was made of the impact of the rehabilitated Union Station on major nearby intersections. The analysis indicated that approximately 50 percent of Union Station’s retail customers would already be in the Station for other purposes, and that most of the restaurant customers (60 percent of sit-down restaurants, and 80 percent of fast-food restaurants) would be in the same category. The offices, on the other hand, would be primary purpose trip generators. Based upon trip generation rates published by the Institute of Transportation Engineers, the retail and office activities planned for Union Station are expected to gen- erate about 5000 additional round-trip vehicular trips per day, broken down as follows: AM Peak PM Peak In Out In Out Daily Volume Use One Way One Way One Way Two Way Retail 63 58 144 153 3,690 1,845 Sit-down restaurant 17 9 55 34 1,498 749 Fast-food restaurant 37 27 119 102 3,871 1,936 Offices 149 28 22 109 984 492 Total 266 122 340 398 10,043 5,022 Total rounded 270 120 340 400 10,000 5,000 The approach of these vehicles to Union Station may be expected from the fol- lowing directions: Street Percent of Traffic North Capitol 30 H Street (West) 60 H Street (East) 5 Massachusetts Avenue (Southeast) 5 The analysis indicated that the additional traffic volume through the most heavily impacted intersection, North Capitol and H Streets, N.W., would be as follows: Approach a.m. p.m. North 81 102 South 0 0 West 162 204 East 108 360 From this, it was concluded that, with proper signal timing and related transporta- tion system management techniques, the added traffic would produce the following lev- els of service at North Capitol and H Streets, N.W. in the evening peak hour: © 1999 by CRC Press LLC Approach Service Level North C/D South D West D East C These are considered acceptable service levels by the District of Columbia. Other less travelled traffic intersections, such as North Capitol Street and Massachusetts Avenue, N.W., and Third and H Streets, N.W., would have a lesser traffic increase. Accordingly, the proposed action would not have a significant impact upon vehicular traffic on major streets servicing the Union Station area. Parking The next table provides a breakdown of expected users of the 1296 space garage now under construction in the Union Station complex. It also shows the potential users if the garage capacity is extended to two bays to include 1830 or to three bays to contain 2114 spaces. The Barton-Aschman estimate of user categories for the 1296 space structure includes 120 spaces (10 percent of capacity) to accommodate 360 office employees and a total of 303 spaces (25.4 percent of capacity) for retail purposes, including both employ- ees and shoppers. On this basis, the redeveloped Union Station, including office employ- ees, would only encompass about 35 percent of the garage capacity. This is not an unduly large percentage and therefore would not have a significant impact on the garage opera- tion over and above that anticipated before garage construction was resumed in 1984. Sverdrup and Parcel’s 1984 analysis of parking demand, expansion feasibility, and parking fees projected a level of retail activity at Union Station which could utilize at least 700 spaces, requiring a garage with 1640 spaces in 1986 or shortly thereafter. On the basis of overall projected growth at Union Station, including increased Amtrak patronage, the study projected the need for a 1820 space garage in 1993 and 2000 spaces by the year 2000. Growth resulting from the Union Station redevelopment project could be considered to have a potential long-term impact of significance to the extent that it represents a potentially larger user of parking space than in near term. Yet, realistically it can also be reasoned that this is a speculative possibility whose potential significance was recognized when the present garage construction was still in the planning stage. Moreover, any difficulties resulting from a parking shortage would be compensated for by the ready availability of public transportation to and from Union Station. For these reasons, and certainly in the near term, the proposed Union Station reha- bilitation project cannot be considered to have a significant impact on parking at Union Station. Metro Metro officials do not anticipate a need for increasing the number of buses which now serve Union Station. If necessary, they plan to emphasize use of Metrorail to minimize above-ground congestion. Regardless, this would involve only the use of additional sub- way cars rather than a revised schedule. Accordingly, the proposed Union Station reha- bilitation will not have a significant impact on Metro operations. Taxi and Auto Dropoffs Some portion of potential retail customers at Union Station will be picked up or dropped off in the Columbus Plaza area in front of Union Station. © 1999 by CRC Press LLC Projected Union Station Parking Structure Users Previous Plan 1 2-Bay Expansion 2 3-Bay Expansion 2 User Category 1296 Spaces 1830 Spaces 2114 Spaces Office 120 (10.0%) 120 (7.0%) 175 (8.8%) Retail 303 (25.4%) 700 (40.8%) 765 (38.5%) Amtrak 624 (52.3%) 625 (36.4%) 750 (37.7%) Terminal employees 0 (0%) 90 (5.2%) 90 (4.5%) Rental car 75 (6.3%) 125 (7.3%) 125 (6.3%) Tourmobile 0 (0%) 50 (2.9%) 50 (2.5%) Residual 3 70 (5.9%) 5 (0.3%) 34 (1.7%) Circulation Reserve 4 104 (N/A) 115 (N/A) 125 (N/A) 1296 1830 2114 1 Barton-Aschman Report. 2 Base condition used for 2-bay expansion; best condition used for 3-bay expansion. 3 Residual category used to define capacity available for purposes other than defined categories. 4 Retail, Amtrak, and Tourmobile parking supply (8 percent). Source: From Sverdrup and Parcel. Projected Parking Need, Union Station Garage Parking Capacity Required 1986 1993 2000 Development Category Base Best Base Best Base Best Office 120 175 120 175 120 175 Retail 700 765 700 765 700 765 Amtrak 495 595 625 750 770 920 Terminal employees 75 75 90 90 110 110 Rental car 100 100 125 125 125 125 Tourbus 50 50 50 50 50 50 Reserve 100 115 110 125 125 140 Capacity required 1640 1875 1820 2080 2000 2285 Demand/capacity ratio, 2 bays 0.90 1.02 0.99 1.14 1.09 1.25 Demand/capacity ratio, 3 bays 0.78 0.89 0.86 0.98 0.95 1.08 Existing garage capacity = 1296 Total capacity, 2-bay garage expansion = 1830 Total capacity, 3-bay garage expansion = 2114 (Recommended plan) Source: Sverdrup and Parcel. The 1982 garage/ramp assessment (1) examined the question of taxi queuing and dropoffs. It determined by survey that the maximum accumulation of cabs was 30 to 35 at any one time during the 3:00 p.m. through 6:40 p.m. peak period. The longest queues lasted only 10 to 15 minutes and dissipated quickly once the passengers had been accommodated. Of particular interest was the volume of cabs arriving (40 percent) and © 1999 by CRC Press LLC leaving (70 percent) with no passengers. This indicated there should be ample taxi ser- vice for retail customers at Union Station with little or no change necessary in existing taxi service patterns. Private automobile pickups and dropoffs of potential retail customers will most likely occur at an elevated rear access using the First Street ramp. This is an area well removed from the taxi queuing area on the east side of Union Station and therefore it will have no significant impact upon transportation and circulation at Union Station. Construction Impacts Some degree of inconvenience to Union Station users is unavoidable during the con- struction period. Project planning will seek to reduce these inconveniences to a practi- cal minimum through construction phasing and, if necessary, temporary facilities. Station services and access to platforms, public streets, and the Metro subway must be maintained throughout the Station renovation which is expected to last 16 months. This will be accomplished by keeping the existing replacement station in service while the historic structure is renovated. Upon completion of the restoration and renovation work in the historic structure and the creation of a new passenger station within and adjoining, station operations will be relocated to the renovated Union Station. Passengers will have access to the trains and all platforms from the rear of the connecting structure. Construction activities are not expected to affect bus, taxi, passenger car, or sub- way access to the existing temporary structure. No change in traffic patterns or existing parking is anticipated. Almost 100 percent of the work is to be accomplished inside the historic structure to which the public has no access. In summary, the increase in traffic resulting from the renovation and rehabilitation of Union Station will not have a major adverse impact on traffic circulation and parking in the area of the Station. The proposed project will generate an estimated 5000 vehic- ular round trips a day but the increased peak-hour traffic in the most heavily-impacted intersection, North Capitol and H Street, N.W., will fall within an acceptable service level. The incremental increase in parking demand will not have a significant, unantic- ipated near-term impact upon parking or upon Metro, taxi, or auto dropoff activities. The construction operations required to carry out the project will not have an impact upon bus, taxi, passenger car, or subway access to the replacement station. All other alternatives discussed in Section 2.1 would have lesser impacts on traffic circulation or parking than will the selected alternative.” REFERENCE Environmental Assessment of Rehabilitation of Union Station as a Rail/Commercial/Office Facility, under subcontract to James W. Collins and Associates, BREGMAN & COM- PANY, February 1985. © 1999 by CRC Press LLC . and future levels-of-service at the major intersections in the Union Station area indicated that the garage/ramp project would not have an impact sufficient to change the levels-of-service which. follow- ing discussion is derived from that report, supplemented with an analysis of the additional impacts projected to result from the proposed project to rehabilitate Union Station. Levels-of-service. of vehicles with frequent stoppages. Existing Traffic Levels-of-Service at Major Intersections Intersection Approach From Level-of-Service North Capitol and North B Massachusetts Avenue, N.W.