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31 Since park-and-ride spaces encourage automobile access to Bridge. Since four freeways converge at the toll area at the east stations and discourage pedestrian, bicycle, and bus access, bay approach to the bridge, the six lanes (for each direction) this implies that the transit line is designed to primarily serve of the bridge serve as a bottleneck to the ten lanes that feed it. corridor trips for people living within the corridor, as opposed Both employment and housing densities (9.3 and 3.5 per to casting a wider net and attracting automobile-to-transit acre, respectively) are below the study averages (12 and 5 per transfers that often originate farther away. acre, respectively). The density of four-legged intersections in The placement of the Blue Line's stations in relation to the the corridor is similarly below average and together with the highway facility encourages non-automobile access as well. other urban form indices, suggests a moderately automobile- On average, the distance from the corridor's stations to the oriented corridor. However, there are meaningful variations in highway is roughly 0.20 mile--higher than the average distance the corridor's urban form that help explain its success. Down- for the rest of the study corridors of 0.15 mile. However, most stream of the Caldecott Tunnel, the corridor runs through the of this high average distance is due to the separation of stations inner-ring suburbs and increasingly urban areas of Berkeley from freeway in the downstream segment, where the gap is up and Oakland. This segment has higher residential densities to a half-mile, while the upstream segment has stations placed than the upstream segment, where more recent, low-density largely in the median of the freeway. This relatively large suburban development patterns have dominated. distance in the downstream segment mitigates some of the Similarly, the corridor's stations are best described as negative impacts of the highway on the transit line and has automobile-oriented in design and function, but the upstream allowed the station areas there to maintain a transit-oriented stations more so than the downstream stations. Overall, the urban form. Overall, these factors combine to make this cor- average number of park-and-ride spaces per station in this ridor one of the most transit-friendly, in terms of urban form, corridor is roughly 1,600--more than double the study average of the study cases, largely due to its transit orientation of the of 620. The corridor's stations are also very close to the high- downstream segment. way (roughly 0.05 mile on average, compared to the study average of roughly 0.13), providing an attractive option to San Francisco East Bay (BART) Pittsburg/ highway drivers to exit, quickly park, and complete their Bay Point Line/S.R. 24 trips via BART. However, the most automobile-oriented stations are generally in the upstream segment, while the The San Francisco BART's Pittsburg/Bay Point line runs downstream segment's stations tend to have fewer park- from the East Bay suburbs of Pittsburg, Bay Point, Concord, and-ride spaces and are designed to be friendlier to pedes- and Walnut Creek to downtown Oakland and San Francisco. trian access. Here, as in the cases discussed above, restricting the freeway's In terms of multimodal coordination, the average station capacity has been important to the adjacent transit line's spacing for the Pittsburg/Bay Point Line (6.42 miles) is dramat- success. But in the Pittsburg/Bay Point corridor, there are ically longer than the average interchange spacing for State actually two freeway capacity constraints. The first occurs Route 24 (0.93 mile), resulting in a highly complementary where Highway 24 and the BART line bore through the corridor with a Coordination score of 5.5 miles. However, Oakland/Berkeley hills to reach the core Bay Area; the Caldecott Tunnel shrinks the freeway's capacity from eight to six station spacing gets shorter in the downstream segment, lanes. The center bore of the tunnel is reversible, so during providing better access from the BART line to the local land commuting hours, the peak direction of flow always has uses than in the upstream segment. Clearly, this configuration four lanes of travel. However, the nonpeak direction is re- provides a speed advantage to the BART line in the upstream duced to two lanes, and as a result, there is almost always segment compared to other heavy rail systems with shorter congestion and delay in both directions of travel during the station spacings and, functionally, means the line in the A.M. and P.M. peak commute hours at the tunnel. While this upstream segment operates almost more as a commuter rail nonpeak-direction capacity constriction does not directly line than heavy rail. This higher operating speed, plus the encourage peak direction use of the BART line, it does restrict near-constant congestion at the Caldecott Tunnel and the Bay nonpeak direction flow, thereby providing direct incentive for Bridge, gives the BART line a chance to capture a respectable nonpeak direction BART ridership and indirectly promoting share of corridor travel. the general perception that BART is the more hassle-free corridor alternative. Corridor Evolution The second constraint occurs at the San Francisco Bay crossing itself, where BART runs in a submerged tube beneath Corridor travel patterns and built environments can change the water and mud of the bay floor, while automobiles run in dramatically over time. Often, changes in land uses and trans- a parallel alignment across the San Francisco-Oakland Bay portation facilities affect each other. The new paradigm offers
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32 ideas and tools to harness, guide, and shape these changes, the evolution of freeway-only, automobile-oriented, and old with the goal of creating a corridor where all modes can paradigm corridors into transit-oriented corridors. Park- flourish within a sustainable and livable environment. and-ride-access and transit-optimized/freeway-constrained Although the new paradigm typology offers three scenarios, corridors need not be seen as end-states, but steps along the as described above, each of these should not be seen as a nec- evolutionary path toward livable, sustainable, efficient transit- essary end-state. The new paradigm is designed to encourage oriented corridors (see Figure 3-2). Freeway-Only Corridor - Freeway dominates corridor travel - Automobile-oriented land uses Old Paradigm Multimodal Corridor LEGEND Transit Line - Freeway dominates corridor travel - Transit as congestion reliever Transit Sta. - Automobile-oriented land uses Freeway - Long int. & sta. spacings - Sta. & int. co-located Freeway Int. - Park-&-ride access emphasis for sta. New Paradigm Corridor: Park-&-Ride Access - 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: Transit-Optimized/ Freeway Constrained - Hybrid multimodal corridor - Park-&-Ride segment: upstream - Transit-Oriented segment: downstream Upstream (Non-CBD) Segment Downstream (CBD) Segment Freeway Capacity Constraint New Paradigm Corridor: Transit-Oriented - 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. Figure 3-2. Possible paths to developing transit-oriented new paradigm corridors.
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33 Therefore, although the success of the new paradigm requires planners often must give up on the idea of competing with the identification of a clear, consistent and widely supported the freeway on the basis of comparative travel times or offer vision for what the multimodal corridor will look like and a higher level of accessibility to corridor land uses. In the how it will function in the long term, it does not require these planned Greenwich/Norwalk BRT line, system planners are changes to all take place at once. Rather, a long-term vision focusing on incremental improvements to existing corridor can be realized through a series of incremental improvements transit services that provide improved transit travel times over time, with each step building on the last to create gradual between the relatively dense urban centers of Greenwich and and sustainable changes. Norwalk, Connecticut. Introducing a new transit line to a corridor is particularly While a full BRT alternative was considered, corridor challenging, for all the reasons discussed in this report. There- planners opted for a more incremental approach. Planned fore, it is often unrealistic to assume that even the most radical improvements include an on-street signal preemption system and well-financed changes to an existing automobile-oriented, to reduce intersection delays, a "priority lane," which will be freeway-only corridor can yield a successful transit-oriented shared between transit vehicles and mixed traffic, queue-jump new paradigm corridor immediately. However, if transit is lanes, and a suite of intelligent transportation systems to introduced using the principles of the new paradigm's park- provide real-time bus arrival and departure information at and-ride access model, it can establish its own share of the cor- bus stops, travel times, schedule adherence, and automatic ridor's travel market. Once successful as a park-and-ride access announcement information. corridor, incremental changes can be introduced that can help In addition, incremental improvements will be made to it transition to becoming more transit-oriented over time. intermodal terminal stops to improve quality of service and Bus rapid transit can be a cost-effective park-and-ride access reduce dwell times. Figure 3-3 illustrates the improvements mode to start this evolutionary process. The following sections to routing that the "enhanced bus service" will provide and describe how BRT and other incremental improvements can also shows the alignment of a dedicated transitway that will be introduced as stepping stones leading to a more transit- give dedicated right-of-way access into the Stamford Trans- oriented new paradigm corridor. portation Center. Incremental Transit Improvements: Hybrid Multimodal Corridors: Steps Toward Full BRT and the New Paradigm Taking Advantage of Changing Corridor Urban Form Off-freeway BRT alignments in multimodal corridors can be problematic. When BRT does not run on a grade-separated No two corridors are the same. Each metropolitan area, alignment and must travel in mixed-flow, on-street traffic, 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.