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Reinventing the Urban Interstate: A New Paradigm for Multimodal Corridors (2011)

Chapter: Chapter 3 - Existing Multimodal Corridors What Can We Learn From Them?

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Suggested Citation:"Chapter 3 - Existing Multimodal Corridors What Can We Learn From Them?." National Academies of Sciences, Engineering, and Medicine. 2011. Reinventing the Urban Interstate: A New Paradigm for Multimodal Corridors. Washington, DC: The National Academies Press. doi: 10.17226/14579.
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Suggested Citation:"Chapter 3 - Existing Multimodal Corridors What Can We Learn From Them?." National Academies of Sciences, Engineering, and Medicine. 2011. Reinventing the Urban Interstate: A New Paradigm for Multimodal Corridors. Washington, DC: The National Academies Press. doi: 10.17226/14579.
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Suggested Citation:"Chapter 3 - Existing Multimodal Corridors What Can We Learn From Them?." National Academies of Sciences, Engineering, and Medicine. 2011. Reinventing the Urban Interstate: A New Paradigm for Multimodal Corridors. Washington, DC: The National Academies Press. doi: 10.17226/14579.
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Suggested Citation:"Chapter 3 - Existing Multimodal Corridors What Can We Learn From Them?." National Academies of Sciences, Engineering, and Medicine. 2011. Reinventing the Urban Interstate: A New Paradigm for Multimodal Corridors. Washington, DC: The National Academies Press. doi: 10.17226/14579.
×
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Suggested Citation:"Chapter 3 - Existing Multimodal Corridors What Can We Learn From Them?." National Academies of Sciences, Engineering, and Medicine. 2011. Reinventing the Urban Interstate: A New Paradigm for Multimodal Corridors. Washington, DC: The National Academies Press. doi: 10.17226/14579.
×
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Suggested Citation:"Chapter 3 - Existing Multimodal Corridors What Can We Learn From Them?." National Academies of Sciences, Engineering, and Medicine. 2011. Reinventing the Urban Interstate: A New Paradigm for Multimodal Corridors. Washington, DC: The National Academies Press. doi: 10.17226/14579.
×
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Suggested Citation:"Chapter 3 - Existing Multimodal Corridors What Can We Learn From Them?." National Academies of Sciences, Engineering, and Medicine. 2011. Reinventing the Urban Interstate: A New Paradigm for Multimodal Corridors. Washington, DC: The National Academies Press. doi: 10.17226/14579.
×
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Suggested Citation:"Chapter 3 - Existing Multimodal Corridors What Can We Learn From Them?." National Academies of Sciences, Engineering, and Medicine. 2011. Reinventing the Urban Interstate: A New Paradigm for Multimodal Corridors. Washington, DC: The National Academies Press. doi: 10.17226/14579.
×
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Suggested Citation:"Chapter 3 - Existing Multimodal Corridors What Can We Learn From Them?." National Academies of Sciences, Engineering, and Medicine. 2011. Reinventing the Urban Interstate: A New Paradigm for Multimodal Corridors. Washington, DC: The National Academies Press. doi: 10.17226/14579.
×
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Suggested Citation:"Chapter 3 - Existing Multimodal Corridors What Can We Learn From Them?." National Academies of Sciences, Engineering, and Medicine. 2011. Reinventing the Urban Interstate: A New Paradigm for Multimodal Corridors. Washington, DC: The National Academies Press. doi: 10.17226/14579.
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26 This chapter presents three types of new paradigm multi- modal corridors, discusses the evolution of corridors from one type to another, and compares the old and new paradigms for multimodal corridors. Types of New Paradigm Multimodal Corridors The new paradigm focuses on helping transit to compete effectively with and complement a neighboring freeway facility by establishing one of the following types of multimodal corridors: • Transit-oriented: an operating environment conducive to transit, bicycle, and pedestrian access to the transit facility • Park-and-ride access: an operating environment conducive to automobile access to the transit facility • Transit-optimized/freeway constrained: an environment where transit is given an operational advantage over the freeway by constraining the capacity of the freeway Transit-Oriented Multimodal Corridors Transit-oriented new paradigm corridors are designed to provide high levels of transit access within the corridor and high automobile speeds with low local (i.e., infrequent) access on the freeway. High levels of transit access are achieved by providing relatively short station spacings (between 0.50 and 0.75 mile); high automobile speeds and low local freeway access comes from relatively long interchange spacings (more than 1 mile) on the freeway. This allows the transit line to serve short- and medium-length trips, while the freeway facility is oriented toward long-haul and through trips. Urban form in these corridors typically has high levels of residential and employment densities and a grid street network that encourages nonautomobile travel in station areas. Ideally, travel flows through the corridor will be relatively balanced, so that both the capacities of the freeway and transit line are maximized. The transit line’s stations are designed to favor nonauto- mobile access. Trip origin stations are placed as far as possible from the freeway and its off-ramps to reduce both the amount of automobile traffic in the station-area neighborhoods and the negative externalities of the freeway facility. With the possible exception of end-of-the-line (terminal) stations, stations have few, if any, park-and-ride spaces, and bus bay or other bus connection facilities are sited to maximize bus access to the stations without disrupting pedestrian and bicycle access. Corridor land uses and station area access are transit- oriented, with higher density, mixed-use, and pedestrian- friendly development. Where it Works There are no multimodal corridors that are consistently transit-oriented over their entire lengths. However, there are cases where segments of multimodal corridors meet the transit- oriented criteria. Examples include • Washington D.C. Orange Line/I-66: from Ballston MU Station to Rosslyn Station • Chicago Blue Line/Kennedy Expressway (I-90): from Bellmont-Blue Station to Clinton Green Station • San Francisco East Bay (BART) Pittsburg/Bay Point Line/ S.R. 24: Rockridge Station to 19th Street Station Since these corridors are also transit-optimized/freeway constrained cases, further discussion is provided in the Transit- Optimized/Freeway Constrained Corridors section below. Park-and-Ride-Access Multimodal Corridors Park-and-ride-access new paradigm corridors are designed to provide high levels of automobile access and high transit C H A P T E R 3 Existing Multimodal Corridors— What Can We Learn From Them?

27 speeds. This is achieved by designing the corridor’s transpor- tation facilities in an automobile-oriented complementary fashion, taking advantage of the already-existing freeway’s rela- tively short interchange spacings (between 0.25 and 0.50 mile) and designing the transit line to have relatively long station spacings (more than 0.75 mile). Urban form in these corridors is distinguished by • One (or more) highly concentrated employment cen- ters (i.e., single or multiple business districts) • Relatively low residential densities (at least, within a mile or so of the transit line) • A high-capacity street network that favors automobile access to the transit stations Transit trip origin stations (i.e., the non-business district sta- tions) are close to the freeway off-ramps, have ample park-and- ride capacity, and have a high-capacity street network nearby to handle the peak-period demand at stations from park-and- riders and pick-up/drop-off activities. By contrast, transit trip destination stations (i.e., the business district stations) are placed far from the freeway to promote pedestrian activities within employment centers. In these multimodal corridors, transit provides a long-haul travel alternative to the freeway. Where it Works • Chicago Red Line/Dan Ryan Expressway (a transitional case—see discussion below) • Los Angeles Green Line/Century Freeway • Denver T-REX/I-25 Corridor Chicago Red Line/Dan Ryan Expressway. The Chicago Red Line/Dan Ryan Expressway is an excellent example of a multimodal facility. It serves various residential uses within the city. This includes a number of neighborhoods with du- plexes and single-family homes. Although the freeway was built first, the Red Line was an important complement to the original south side elevated line. The Red Line extends to the north side of the city and connects with other Chicago Transit Authority (CTA) rapid transit lines in downtown Chicago. All stations are served by bus lines on intersecting streets. Sections of the freeway consist of 14 lanes of through traffic. Many of the freeway sections have continuous service roads. The corridor shares one important element with other Chicago multimodal corridors—the size of Chicago’s cen- tral business district (CBD). As discussed earlier, the CBD provides a regional concentration of destinations, which encourages people to use transit. In terms of multimodal coordination, the average station spacing for the Red Line (1.11 miles) is more than a half-mile longer than the average interchange spacing for the Dan Ryan Expressway (0.50 mile) suggesting an automobile-oriented complementary corridor. This difference divides the travel market within the corridor into roughly two segments— long-haul, high-speed transit riders and freeway-accessible, more dispersed travel locations. It seems likely that this de- sign helps the Red Line compete with and complement the freeway to attract transit riders despite the corridor’s sta- tion access characteristics and its lack of clear automobile- versus transit-orientation in terms of urban form. Perhaps the most notable transit-oriented characteristic for the Red Line is the lack of park-and-ride spaces at its stations. In general, the Red Line relies on bus-to-rail transfers and pedestrian access. There are several bus transfer stations located within the freeway right-of-way, and the 95th Street Terminal station is one of the busiest in the system. Therefore, while its surrounding corridor land uses and its multimodal coordi- nation represents an auto-orientation, its lack of park-and- ride facilities suggests that the Red Line should be considered as a transitional example from its transit-oriented cross- town neighbors (the Eastern Kennedy and Eisenhower Blue Lines) to the more automobile-oriented, park-and-ride ac- cess examples that followed it. Los Angeles Green Line/Century Freeway. Los Ange- les’s Green Line/Century Freeway is a more recent example of a park-and-ride access corridor. While light rail generally has lower operating speeds and carrying capacities than commuter or heavy rail, the Green Line attracts roughly 42,000 average weekday boardings, making it one of the top performers in this study. Furthermore, and perhaps most striking, the Green Line does not directly serve a concentrated activity center or central business district. All the other case study corridors have a radial alignment, running like a spoke on a wheel from a central business district, but the Green Line is circumferential and runs from east to west, well south of downtown Los Angeles. Adding further challenges to the success of the Green Line, the Los Angeles region is the prototypical automobile-oriented metropolitan area. Although downtown Los Angeles is large enough to support a light rail line, with roughly 40 million square feet of office space, most of Los Angeles’s trip attrac- tors are dispersed throughout the region in a polycentric fashion. Finally, like all multimodal corridors, the Green Line com- petes for ridership with its freeway neighbor. The more capacity the freeway has, the more difficult it is for transit to compete. The Century Freeway is a ten-lane facility, the largest freeway in our study. Nevertheless, the Green Line is relatively successful when compared to other multimodal corridor transit lines. Part of the Green Line’s success may be its role as a transfer facility, feeding the Blue Line, a radial alignment light rail line

28 that serves downtown Los Angeles. Ridership data supports this interpretation, since a substantial number of Green Line riders transfer at the Imperial/Wilmington station on to the Blue Line. The Green Line also serves non-CBD employment and activity centers, such as the nearby Los Angeles International Airport (LAX). This would appear at first glance to be a sub- stantial trip attractor that would mitigate the lack of direct service to a CBD, but the Green Line’s nearest station to LAX (Aviation/LAX) is roughly a mile from the airport and riders have to transfer to a shuttle to reach the airport. Nevertheless, there is a fair amount of employment in the Green Line cor- ridor, if dispersed. It has an employment density of roughly 10 employees per acre, just below the average of 11.5 for all study corridors. This is particularly impressive since some of the study corridors have downtown stations, raising the study average substantially. Residential corridor densities are low in this corridor, with an average (gross) housing density of 3.4 dwelling units per acre (compared to an average of 5 dwelling units per acre for all study corridors). This pattern is ideal for maximizing automobile mobility, but is difficult to serve effectively with high-capacity transit. In terms of multimodal coordination, the average station spacing for the Green Line (1.68 miles) is more than a mile longer than the average interchange spacing (0.65 mile) sug- gesting an automobile-oriented complementary corridor. This substantial difference divides the travel market within the corridor into two segments: long-haul, high-speed transit riders and freeway-accessible local travelers. This complemen- tary coordination works synergistically with the predominantly automobile-oriented land uses and stations to overcome the Green Line’s challenges in this corridor. Denver T-REX/I-25. Denver’s Southeast Transportation Expansion Project (T-REX) line extends along the west side of reconstructed Interstate 25 to Lincoln. LRT lines to Union Station and to 16th Street in the eastern part of the CBD link both trunk lines with the City Center (see Figure 3-1). The T-REX/I-25 corridor, which was built and opened in 2006 has been very successful at attracting transit riders. That this corridor has attracted a substantial transit ridership, despite the increased capacity brought by the T-REX project’s free- way widening, suggests there is a great deal to be learned from this case. Urban form in the corridor before the project’s opening suggests an extremely automobile-oriented pattern. Housing densities were among the lowest found in the study group, with less than 1 unit per acre (gross), substantially less than the study average of roughly 5. Employment is also low, with an average density of roughly 5 employees per acre (gross), less than half the study average of nearly 12. In terms of urban design, this corridor is decidedly automobile-oriented, as well. This study employed a proxy indicator of urban design that measured the average density of four-legged intersections in the travel corridor (see the discussion of Land Use and Urban Design characteristics in Chapter 5). With an average density of 0.4 four-legged intersections per acre compared to the study average of 0.9, this corridor has a street grid pattern that is decidedly suburban and automobile-oriented. However, the size of Denver’s CBD (roughly 23 million square feet) and the fact that the line also serves the Denver Tech Center—an office park concentration south of the CBD— seems to help overcome these automobile-oriented corridor challenges, providing a relatively strong anchor on which to build the transit line’s ridership. Station access indices used in this study also suggest a corridor that has been designed to maximize automobile-to- station transfers. On average, there are roughly three freeway ramps touching down within a quarter-mile of each station (higher than the 2.75 study average), suggesting that the T-REX light rail line was designed to offload traffic from the freeway onto transit. The average distance between stations and the free- way is roughly 0.05 mile, well below the study average of 0.13. While the number of park-and-ride spaces per station in this corridor (513) is below average compared to the study group (620), it is well above the average for study corridors that have light rail transit (324), suggesting that for a light rail line, this corridor’s stations are highly automobile-oriented. Transit-Optimized/Freeway Constrained Multimodal Corridors The distinguishing feature of these corridors is the restricted capacity of the freeway facility. Constraining freeway capacity gives the corridor’s transit line a performance advantage over its freeway neighbor. Ideally, these corridors will combine the constrained freeway facility with either transit-oriented or park-and-ride access features to take full advantage of transit’s performance advantage. More specifically, • In the “upstream” (non-CBD) section of the corridor before the freeway capacity constraint, the corridor is typically designed in a park-and-ride-access fashion where transit services are oriented toward long-haul commuter travel. Land uses and station access characteristics are generally automobile-oriented. Interchange spacings on the freeway are shorter than the transit station spacings, providing access to local corridor land uses by automobile. • In the “downstream” or CBD segment, the corridor is designed in a transit-oriented fashion, with the transit line oriented toward short-haul travel. Land uses and station access in this downstream segment are generally transit- oriented as is the multimodal coordination, with long inter- change spacings and short station spacings.

Source: Colorado Department of Transportation, T-REX Fact Book. Figure 3-1. Denver’s I-25/T-REX corridor alignment. 29

30 Where it Works • Washington DC Orange Line/I-66 • Chicago Blue Line/Kennedy Expressway (I-90) • San Francisco East Bay (BART) Pittsburgh/Bay Point Line/ S.R. 24 Washington DC Orange Line/I-66. Washington DC’s Orange Line runs into the District of Columbia from the Virginia suburbs to the west along Interstate 66. The rapid growth seen in this area over the past 30 years is an important part of the story behind this corridor’s success. Interstate 66 is a unique case in that it was purposely built as a capacity- restricted facility. Its four to six lanes could have easily been built as eight or more to handle the rapid growth in the corridor. However, as a part of the financing package from Congress to fund the construction of the Orange Line, the Interstate was restricted to six lanes.1 While the section between Washington DC and the Theodore Roosevelt Bridge is designated as an HOV-2-only facility during peak periods, the capacity restriction still serves to effectively discourage automobile traffic on the inner section of this corridor. As such, this case sets an example of how freeway capacity restrictions can substantially boost parallel transit line ridership and may also restrict total corridor throughput. The Orange Line’s separation from the freeway as it travels through the Rosslyn neighborhood of Arlington, Virginia, helps to make this one of America’s best example of off-lining an HRT alignment to leverage TOD. Since the corridor has developed from largely rural countryside to low-density suburban with large “edge city” concentrations, urban form is decidedly automobile-oriented in its non-CBD, upstream, segment and largely transit ori- ented in its downstream segment. Housing densities in the corridor—about 2.4 units per acre—are well below the study average of roughly 5 units per acre. In suburban fashion, the street network in this corridor is largely automobile-oriented (largely curvilinear as opposed to a grid design) as suggested by the relatively low density of four-legged intersections (0.7 for the corridor compared to 0.9 for the study cases). However, this corridor is rich with transit-oriented employ- ment in its downstream segment. The Orange Line runs through several suburban “edge cities.” As a result, the employ- ment density for this corridor is estimated to be roughly 39 employees per acre, more than triple the study average of 12. Washington DC’s central business district is large as well, with over 95 million square feet of office space, providing a strong set of anchors to the corridor’s travel patterns and encouraging use of the transit line. These segmented land use patterns—with automobile-oriented forms upstream and transit-oriented downstream—create an effective hybrid corridor that matches the design of the freeway and transit line to local urban form patterns. The result is a highly successful transit line—the only case in this study where the transit line’s average daily boardings (139,000) exceed the estimated person trips of the freeway (127,000). Chicago Blue Line/Kennedy Expressway (I-90). The Kennedy Corridor is unique in several respects. Built in 1962, its southern section was placed adjacent to the already existing Union Pacific Northwest Line; as a result, the neighborhood impacts of this portion of the Blue Line and the Expressway were minimized. Land uses in this corner of Chicago were established early and are distinctly transit-oriented in its downstream segment and automobile-oriented in its upstream segment. There are several reasons for this corridor’s success. First, it has a heavy rail line that provides fast, high-capacity transit service directly to downtown Chicago. This transit advantage is complemented by the freeway’s design, which has a relatively modest six lanes in its western portion, giving the rail line an advantage during peak congestion hours on the freeway. However, once I-90 merges with I-94 in the southern section, the freeway facility widens to include eight general-purpose lanes and two center-median reversible lanes, providing higher freeway capacity to handle the added traffic from I-94. This freeway merge (and the reduction in total lanes from the two upstream feeder freeways) helps make the transit share of total person-trips in the corridor 16 percent and placing its ranking at fifth-highest among the study corridors. This corridor’s success is also due in part to the way the transit line and the freeway were designed to match the vari- ations in the corridor’s land uses and urban designs. Overall, housing densities in the corridor are a respectable 10 units per acre (gross) but with significant variations within it. The up- stream segment generally has lower densities and the down- stream segment higher. Employment densities show a similar variation, with the downstream segment providing direct access to the CBD. Downtown Chicago has one of the largest concentrations of non-commercial floorspace in the United States and is the second-largest of the study corridors. This provides a large anchor at the end of the corridor that attracts commuters to use the transit and highway facilities. The corridor’s street network is also designed in a pedestrian/ transit-friendly form, with a larger-than-average density of four-legged intersections per square mile, but again, the upstream street patterns are slightly more suburban than the downstream street patterns. Access to the Blue Line’s stations along this corridor is decidedly transit-oriented in design as well, but with similar differences upstream and downstream. Its stations have the lowest number of park-and-ride spaces of any study case.1http://en.wikipedia.org/wiki/Interstate_66

Since park-and-ride spaces encourage automobile access to stations and discourage pedestrian, bicycle, and bus access, this implies that the transit line is designed to primarily serve corridor trips for people living within the corridor, as opposed to casting a wider net and attracting automobile-to-transit transfers that often originate farther away. The placement of the Blue Line’s stations in relation to the highway facility encourages non-automobile access as well. On average, the distance from the corridor’s stations to the highway is roughly 0.20 mile—higher than the average distance for the rest of the study corridors of 0.15 mile. However, most of this high average distance is due to the separation of stations from freeway in the downstream segment, where the gap is up to a half-mile, while the upstream segment has stations placed largely in the median of the freeway. This relatively large distance in the downstream segment mitigates some of the negative impacts of the highway on the transit line and has allowed the station areas there to maintain a transit-oriented urban form. Overall, these factors combine to make this cor- ridor one of the most transit-friendly, in terms of urban form, of the study cases, largely due to its transit orientation of the downstream segment. San Francisco East Bay (BART) Pittsburg/ Bay Point Line/S.R. 24 The San Francisco BART’s Pittsburg/Bay Point line runs from the East Bay suburbs of Pittsburg, Bay Point, Concord, and Walnut Creek to downtown Oakland and San Francisco. Here, as in the cases discussed above, restricting the freeway’s capacity has been important to the adjacent transit line’s success. But in the Pittsburg/Bay Point corridor, there are actually two freeway capacity constraints. The first occurs where Highway 24 and the BART line bore through the Oakland/Berkeley hills to reach the core Bay Area; the Caldecott Tunnel shrinks the freeway’s capacity from eight to six lanes. The center bore of the tunnel is reversible, so during commuting hours, the peak direction of flow always has four lanes of travel. However, the nonpeak direction is re- duced to two lanes, and as a result, there is almost always congestion and delay in both directions of travel during the A.M. and P.M. peak commute hours at the tunnel. While this nonpeak-direction capacity constriction does not directly encourage peak direction use of the BART line, it does restrict nonpeak direction flow, thereby providing direct incentive for nonpeak direction BART ridership and indirectly promoting the general perception that BART is the more hassle-free corridor alternative. The second constraint occurs at the San Francisco Bay crossing itself, where BART runs in a submerged tube beneath the water and mud of the bay floor, while automobiles run in a parallel alignment across the San Francisco-Oakland Bay Bridge. Since four freeways converge at the toll area at the east bay approach to the bridge, the six lanes (for each direction) of the bridge serve as a bottleneck to the ten lanes that feed it. Both employment and housing densities (9.3 and 3.5 per acre, respectively) are below the study averages (12 and 5 per acre, respectively). The density of four-legged intersections in the corridor is similarly below average and together with the other urban form indices, suggests a moderately automobile- oriented corridor. However, there are meaningful variations in the corridor’s urban form that help explain its success. Down- stream of the Caldecott Tunnel, the corridor runs through the inner-ring suburbs and increasingly urban areas of Berkeley and Oakland. This segment has higher residential densities than the upstream segment, where more recent, low-density suburban development patterns have dominated. Similarly, the corridor’s stations are best described as automobile-oriented in design and function, but the upstream stations more so than the downstream stations. Overall, the average number of park-and-ride spaces per station in this corridor is roughly 1,600—more than double the study average of 620. The corridor’s stations are also very close to the high- way (roughly 0.05 mile on average, compared to the study average of roughly 0.13), providing an attractive option to highway drivers to exit, quickly park, and complete their trips via BART. However, the most automobile-oriented stations are generally in the upstream segment, while the downstream segment’s stations tend to have fewer park- and-ride spaces and are designed to be friendlier to pedes- trian access. In terms of multimodal coordination, the average station spacing for the Pittsburg/Bay Point Line (6.42 miles) is dramat- ically longer than the average interchange spacing for State Route 24 (0.93 mile), resulting in a highly complementary corridor with a Coordination score of 5.5 miles. However, station spacing gets shorter in the downstream segment, providing better access from the BART line to the local land uses than in the upstream segment. Clearly, this configuration provides a speed advantage to the BART line in the upstream segment compared to other heavy rail systems with shorter station spacings and, functionally, means the line in the upstream segment operates almost more as a commuter rail line than heavy rail. This higher operating speed, plus the near-constant congestion at the Caldecott Tunnel and the Bay Bridge, gives the BART line a chance to capture a respectable share of corridor travel. Corridor Evolution Corridor travel patterns and built environments can change dramatically over time. Often, changes in land uses and trans- portation facilities affect each other. The new paradigm offers 31

32 ideas and tools to harness, guide, and shape these changes, with the goal of creating a corridor where all modes can flourish within a sustainable and livable environment. Although the new paradigm typology offers three scenarios, as described above, each of these should not be seen as a nec- essary end-state. The new paradigm is designed to encourage the evolution of freeway-only, automobile-oriented, and old paradigm corridors into transit-oriented corridors. Park- and-ride-access and transit-optimized/freeway-constrained corridors need not be seen as end-states, but steps along the evolutionary path toward livable, sustainable, efficient transit- oriented corridors (see Figure 3-2). Freeway Capacity Constraint LEGEND Transit Line Transit Sta. Freeway Freeway Int. Upstream (Non-CBD) Segment Downstream (CBD) Segment - Freeway dominates corridor travel - Automobile-oriented land uses Freeway-Only Corridor - Freeway dominates corridor travel - Transit as congestion reliever - Automobile-oriented land uses - Long int. & sta. spacings - Sta. & int. co-located - Park-&-ride access emphasis for sta. Old Paradigm Multimodal Corridor - Transit focused on long-haul corridor trips - Freeway focused on short-haul trips - Automobile-oriented land uses - Short int. & long sta. spacings - Sta. & int. co-located - Park-&-ride access emphasis for sta. New Paradigm Corridor: Park-&-Ride Access - Hybrid multimodal corridor - Park-&-Ride segment: upstream - Transit-Oriented segment: downstream New Paradigm Corridor: Transit-Optimized/ Freeway Constrained - Transit focus on local access & short-haul trips - Transit-oriented land uses - Long int. & short sta. spacings - Sta. & int. separated except for intermodal sta. - Non-automobile access emphasis for sta. New Paradigm Corridor: Transit-Oriented Figure 3-2. Possible paths to developing transit-oriented new paradigm corridors.

Therefore, although the success of the new paradigm requires the identification of a clear, consistent and widely supported vision for what the multimodal corridor will look like and how it will function in the long term, it does not require these changes to all take place at once. Rather, a long-term vision can be realized through a series of incremental improvements over time, with each step building on the last to create gradual and sustainable changes. Introducing a new transit line to a corridor is particularly challenging, for all the reasons discussed in this report. There- fore, it is often unrealistic to assume that even the most radical and well-financed changes to an existing automobile-oriented, freeway-only corridor can yield a successful transit-oriented new paradigm corridor immediately. However, if transit is introduced using the principles of the new paradigm’s park- and-ride access model, it can establish its own share of the cor- ridor’s travel market. Once successful as a park-and-ride access corridor, incremental changes can be introduced that can help it transition to becoming more transit-oriented over time. Bus rapid transit can be a cost-effective park-and-ride access mode to start this evolutionary process. The following sections describe how BRT and other incremental improvements can be introduced as stepping stones leading to a more transit- oriented new paradigm corridor. Incremental Transit Improvements: Steps Toward Full BRT and the New Paradigm Off-freeway BRT alignments in multimodal corridors can be problematic. When BRT does not run on a grade-separated alignment and must travel in mixed-flow, on-street traffic, planners often must give up on the idea of competing with the freeway on the basis of comparative travel times or offer a higher level of accessibility to corridor land uses. In the planned Greenwich/Norwalk BRT line, system planners are focusing on incremental improvements to existing corridor transit services that provide improved transit travel times between the relatively dense urban centers of Greenwich and Norwalk, Connecticut. While a full BRT alternative was considered, corridor planners opted for a more incremental approach. Planned improvements include an on-street signal preemption system to reduce intersection delays, a “priority lane,” which will be shared between transit vehicles and mixed traffic, queue-jump lanes, and a suite of intelligent transportation systems to provide real-time bus arrival and departure information at bus stops, travel times, schedule adherence, and automatic announcement information. In addition, incremental improvements will be made to intermodal terminal stops to improve quality of service and reduce dwell times. Figure 3-3 illustrates the improvements to routing that the “enhanced bus service” will provide and also shows the alignment of a dedicated transitway that will give dedicated right-of-way access into the Stamford Trans- portation Center. Hybrid Multimodal Corridors: Taking Advantage of Changing Corridor Urban Form No two corridors are the same. Each metropolitan area, and each corridor, has different travel patterns and built envi- Source: Courtesy of South Western Regional Planning Agency and AECOM, Greenwich/Norwalk Bus Rapid Transit Study. Figure 3-3. Planned incremental improvements to the Greenwich/Norwalk Bus Rapid Transit Line over time include the construction of a bus-exclusive transitway. 33

34 ronment qualities. The same goes for corridors themselves. The characteristics and travel patterns within each corridor can vary considerably. To succeed and thrive in a freeway corridor, transit must adapt to these variations. Two of the best-performing transit lines running in multi- modal corridors do just that—they are designed to change their alignments and station access characteristics depending on their surroundings. Chicago’s Kennedy/Blue Line corridor carries nearly 60,000 daily boardings, while Washington DC’s Orange Line/I-66 corridor carries roughly 139,000 daily boardings. Both owe their success in no small part to the hybrid approach system planners took to designing the alignment of these transit lines. Both corridors are split into two halves: an upstream segment (from the line terminus to roughly the midpoint of the corridor) with the transit line and its stations placed in the median or adjacent to the freeway, and a down- stream segment (roughly from the midpoint of the corridor to the CBD) with the line and its stations offset from the freeway. For each of these multimodal corridors, their transit lines and nearby freeways are designed in tune with their sur- rounding contexts. In more suburban environments, further from the regional CBD, park-and-ride access designs are more appropriate, as are transit-oriented designs for more urban environments closer in. Designing a successful new paradigm corridor requires that the transportation facilities match the surrounding land uses and travel patterns—either existing or planned. Once a successful new paradigm corridor is established, then incremental changes can build on these successes, transforming both land uses and transportation facilities into the desired end-state over time. The Old and New Paradigms Compared The key difference between the old and the new paradigms involves the role of the freeway in corridor travel. The interstate was originally designed to serve long-haul, interstate trips. However, as the interstate model evolved over time, interstate freeways became the infrastructure of choice for intraurban travel as well, often displacing transit services into playing a supplementary, congestion-reliever role to their freeway counterparts. There are important differences between the old and new paradigms. Both in terms of their inherent goals and tangible benefits, the new paradigm offers improved performance and efficiencies when compared to the old paradigm. The new paradigm seeks to restore freeways to their originally intended role as long-distance, intercity, and interstate facilities, and provide opportunities for transit to again be the preferred intraurban mode. Other key distinctions include the multi- modal goals inherent in each paradigm, their environmental effects, and the technological, institutional, and planning techniques and models they employ. Table 3-1 summarizes these differences. Table 3-2 provides an overview of the differences in plan- ning, design, and operational approaches between the old and new paradigms. Goals and Benefits Characteristics Old Paradigm New Paradigm Multimodal Goals Corridor Modal Focus Automobile Dominated Multimodal Coordination Supplementary Complementary Freeway Travel Markets Served Short- and Long-Haul Trips Long-Haul/Interurban Trips Transit Travel Markets Served Either Short- or Long-Haul Trips Short-Haul/Intraurban Trips Design Focus Vehicle Throughput Person Throughput Congestion Congestion Relief Reduced Automobile Use Travel Benefits Enhanced Mobility Enhanced Accessibility Freight Increased Capacity Long-Haul/Interurban Focus Environment Environmental Benefits Reduced Congestion-Caused Emissions Reduced Emissions through Mode Shift to Transit Land Use Automobile-Oriented Transit-Oriented Near Stations through Coordinated Corridor Land Use Controls and Policies Station Access Automobile Access Pedestrian/Transit Access Table 3-1. Comparison of the benefits and goals of the “old” and “new” paradigms.

Institutions and Planning Institutional Coordination Highway Department Lead Multimodal Agency Partnerships Planning Focus Responds to Forecasted Travel Demands Shapes Future Pop. & Travel Growth Planning Approach Ad Hoc Design of Transit in Corridor “Intentional” Multimodal Design Implementation Transit Right-of-Way (ROW) “Leftover” ROW in Freeway Corridor • Possible Freeway Lane Conversion for Transit • “Intentional” Multimodal Design New Technologies Goal Freeway Capacity Maximization • Modal Coordination • Maximize Person Capacity Tools • Vehicle Detection • Ramp Metering • Traffic Management Center • Electronic Fare Payment • Multimodal Traveler Information • Parking Applications • Freeway Demand Management • Incident Management • Congestion Pricing • Coordinated Multimodal Pricing • Coordinated Multimodal Incident Management • Corridor-Level Parking Management Table 3-1. (Continued). Characteristics Old Paradigm New Paradigm Motivations for Planning Reacting to economic growth and community and environmental impacts Proactive planning for economic, community, and environmental goals Setting Priorities Moving vehicles Moving people and freight Assessing Needs ♦ Capacity ♦ Throughput ♦ Travel time costs ♦ Reliability ♦ Reduced delay times ♦ Accessibility ♦ Business logistics ♦ Economic competitiveness Analysis Approaches Individual modes and facilities End-to-end trips focusing on multiple modes and the connections between them Planning Processes Emphasis on individual jurisdictions Balanced approach to meeting local, regional, state, and national transportation needs Table 3-2. Approaches to planning, design and operations for old and new paradigm corridors. 35

Next: Chapter 4 - Managing Multimodal Tradeoffs Structuring Corridor Competition and Integration »
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TRB’s Transit Cooperative Research Program (TCRP) Report 145: Reinventing the Urban Interstate: A New Paradigm for Multimodal Corridors presents strategies for planning, designing, building, and operating multimodal corridors—freeways and high-capacity transit lines running parallel in the same travel corridors.

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