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13 alignments keeps the noise impact zone (as well as the im- can compete head-to-head for the long-haul travel market pact zone of fumes, vibration, visual intrusion, and head- in its corridor. light glare at night) within a more limited geographic area. · Minimize transit construction and operations costs: Cost savings are also possible from building one set of sound low-cost transit options are emphasized. walls and other environmental mitigations for both free- · Build automobile-oriented station areas ways and high-speed transit versus two separate investments. Stations are close to freeway on- and off-ramps. Co-alignments can also reduce the safety hazards (and the Generous park-and-ride lots surround suburban stations. costs of mitigating them) of electric third-rails for transit · Build to serve a large central business district (CBD): lines, which must be fenced off if transit runs in its own Transit line should directly serve a large CBD, the larger the alignment. In a freeway co-alignment, the freeway is the better. barrier that prevents people and animals from straying · Use transit as congestion relief: transit line mainly pro- onto a rail right-of-way. vides supplementary capacity to the adjacent freeway--it · Coordinated environmental review: By combining tran- is a reliever or overflow service. sit and freeway facilities, the negative impacts of both facilities together--particularly when sharing the same right- A New Paradigm for of-way--can be analyzed together, yielding potential envi- Multimodal Corridors-- ronmental review cost-savings. Segmented Travel Markets · Transit-oriented development potential: Adding a tran- sit line to a freeway corridor can help create a corridor of The new paradigm offers an optimized combination of high accessibility that can channel development to a more theory, policies, practical applications, and planning processes compact, transit-oriented form while offering users a choice that can help ensure the construction of a thriving, low-cost of travel modes. Although it is unlikely that multimodal transit line operating in concert with its freeway corridor corridors can consistently and evenly achieve transit-oriented neighbor. The old paradigm was based on theoretical assump- urban form patterns seen in transit-only (non-freeway) tions that favored the transit line competing directly with its corridors across the United States, a more modest (but still freeway neighbor for long-haul corridor trips and as a reliever effective) level of density, land use diversity, and pedestrian- service during peak congestion periods. In the new paradigm, oriented design is possible, particularly around select stations however, the planning, design, and engineering efforts of that are insulated from the negative externalities of their multimodal corridors focus on providing distinct, separated, freeway neighbor. and optimized travel markets for each mode--transit line and · Increased nonautomobile mode share: Increased transit freeway--while broadening the perspective of planners and services in a freeway corridor can attract former automobile politicians to use these facilities to fuel the development of patrons to ride transit, thereby reducing fuel consumption, transit-supportive land uses in the corridor. dependence on foreign oil, greenhouse gas emissions, and Market-segmentation between transit and freeway is the air, noise, and water pollution associated with auto- achieved using the following guiding principles and techniques. mobile travel. Increased transit use can also encourage pedestrian and bicycle activities in station areas, further Market-Segmented Transit and reducing the attractiveness of automobile use and creating Freeway Designs (Multimodal Coordination) pedestrian-friendly environments. The concepts and benefits of multimodal coordination are described in greater detail in Chapters 3 and 4. In brief, The Old Paradigm for station spacings and interchange spacings along each facility Multimodal Corridors are designed to give each mode an advantage either in long-haul The history of multimodal corridors is discussed in detail in or short-haul corridor trips. By dividing the travel market Chapter 2. Analysis suggests that there is a paradigm that has within the corridor, the new paradigm offers each mode the been governing the theory and practice of multimodal corridor opportunity to thrive and potentially increases the total development and operations to date--a system of ideas carrying capacity of the corridor. and actions that we will refer to as the old paradigm. This old paradigm has governed the choices (largely in the United States) Market-Segmented Urban Form Patterns made for designing parallel transit and freeway facilities. The basic assumptions of the old paradigm are Transit and freeway facilities thrive within, and encourage their own, distinct land uses. The new paradigm encourages · Design for speed: few stations with long spacings between the development of separated, distinct land use and urban them make for faster transit travel times. This way, transit design environments for each mode within the same corridor.
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14 The planned orientation of urban form should be guided by portation systems (ITS) designed to enhance intermodal trans- the location of each mode's access points--freeway interchange fers and operations. ramp touch-down locations and transit stations. Ideally, transit station areas should have high-density, mixed-use, Intermodal Connections Limited to Key Locations pedestrian-oriented land uses and urban design characteristics, with select station areas designated as freeway- and bus-to- Intermodal transit stations--where park-and-ride lots, transit intermodal station areas. Freeway interchange locations bus transfer facilities, nearby freeway interchange ramps, and should have lower-density, separated uses with street designs cross-corridor pedestrian and bicycle route facilities encourage conducive to smooth traffic operations and freeway access. intermodal transfers--are a critical element of any multimodal corridor. However, since land requirements for intermodal transfer operations are often high, these stations tend to dis- Market-Specific Station Access courage transit-oriented development (TOD). As a result, the Transit stations and stops should be designed to encourage new paradigm encourages limited use of intermodal stations. desired modes of access that are conducive to the surround- These stations should be built at end-of-the-line (terminal) ing land uses and designs of the corridor's multimodal trans- locations and key midline locations where existing bus lines, portation facilities. Corridors that focus on providing freeway- freeway facilities, and/or bicycle and pedestrian routes con- competitive transit speeds should prioritize automobile and verge. In this way, a multimodal corridor should be divided bus access to their stations with a generous supply of park- into separated submarkets, with a few station areas dedicated to and-ride spaces around them, bus bays for quick bus-to-line- intermodal transfers and the rest dedicated to taking advantage haul transit transfers, and "kiss-and-ride" areas near station of and/or encouraging transit-oriented urban form. entrances to allow smooth and quick drop-off and pick-up activities. Automobile-oriented stations should be placed near Intermodal Intelligent Transportation Systems freeway interchange ramps to encourage freeway-to-transit transfers. Information and communications technology systems Corridors that focus on maximizing transit line access offer a wealth of potential for improving and optimizing to corridor land uses should encourage bicycle, pedestrian, intermodal operations in a multimodal corridor. Intermodal and bus access to stations and discourage automobile access. transfers between freeway and transit can be facilitated and Transit-oriented stations should be placed as far from free- encouraged by employing real-time traveler information sys- way interchange ramps as possible to reduce automobile/ tems that provide information on corridor traffic conditions nonautomobile conflicts. (congestion and incidents), transit schedule and schedule adherence, comparative corridor travel times (freeway versus transit), and station and destination parking availability Market Segmentation through and costs. Constrained Freeway Capacity Although sometimes controversial, some multimodal cor- The New Paradigm as a Process ridors have developed divided travel markets by constraining the capacity of the freeway. Washington DC's Orange Line/ Although this offers a new perspective on multimodal cor- I-66 corridor is a prime example of this, where the transit line ridor design and operations, it does not discard the old par- is given a speed/travel time advantage by limiting the capacity adigm methods. Rather, the new paradigm uses the old par- of the freeway to between two and three lanes in each direction. adigm's approach as a potential first step in building a The low ceiling on the carrying capacity of the freeway gives corridor where transit not only survives, but thrives. the transit line an operational advantage, particularly for long- The new paradigm proposed here is based on the intersection haul corridor trips. of three multimodal corridor types, one of which includes the crucial elements of the old paradigm. The new paradigm multimodal corridor could take one of three basic forms: Coordinated and Distinct Intermodal Operations · Transit-Oriented Multimodal Corridors: an operating The new paradigm incorporates two approaches to ensuring environment conducive to transit, bicycle, and pedestrian the maximum amount of interoperability among the transit access to the transit facility line, the freeway facility, and feeder services such as bus lines, · Park-and-Ride Access Multimodal Corridors: an operating and pedestrian and bicycle facilities. These are the sparing use environment conducive to automobile access to the transit of intermodal connections and the use of key intelligent trans- facility (and the form most similar to the old paradigm)
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15 · Transit Optimized/Freeway Constrained Multimodal · Limited Intermodal Stations: With the possible exception Corridors: an environment where transit is given an oper- of end-of-the-line or terminal stations, stations have few if ational advantage over the freeway by constraining the any park-and-ride spaces, bus bays or other bus connection capacity of the freeway facilities that can disrupt pedestrian and bicycle access to stations. Transit-Oriented Multimodal Corridors Park-and-Ride Access Multimodal Corridors Transit-oriented multimodal corridors are designed to give (1) transit a performance advantage in serving short- and Park-and-ride-access multimodal corridors are designed medium-length trips and (2) the freeway a performance advan- to provide high levels of automobile access within, and high tage for serving long-haul corridor trips. This travel market transit speeds through, the corridor. This is achieved through segmentation is achieved through several means: several, mutually supporting design and operational elements: · Transit-Oriented Complementary Multimodal Coordi- · Automobile-Oriented Complementary Multimodal Co- nation: Provide a high density of transit stations with close ordination: Transit provides a long-haul travel alternative spacings (between 0.50 and 0.75 mile) and a low density of to the freeway. The corridor is designed to have a low density freeway interchanges with long spacings (more than 1 mile). of transit stations with long spacings (more than 0.75 mile) This configuration encourages two performance outcomes: and a low density of freeway interchanges with long spacings High transit and low freeway accessibility to corridor (between 0.25 and 0.50 mile). This configuration encourages land uses the following two performance outcomes: High freeway automobile speeds and (relatively) slower Low transit and high freeway accessibility to corridor transit speeds land uses · Transit-Oriented Urban Form: encourage transit- Low freeway automobile speeds and (relatively) high transit speeds supportive land uses and urban design qualities in the · Automobile-Oriented Urban Form: Allow automobile- corridor, particularly near stations, while allowing oriented land uses and urban design qualities in the corridor, automobile-oriented land uses and urban design qualities particularly near interchanges and non-CBD stations, but near freeway interchange ramps. put in place transit-oriented land use controls and plans Station-area urban form: high residential and employ- that will enable the corridor to evolve into a more transit- ment densities in the corridor and a grid-type street friendly environment in the future. network that encourages nonautomobile travel in sta- Stationareaurban form: low residential and employment tion areas. Station area land uses are transit-oriented, densities in most of the corridor, with the exception of with higher density, mixed-use, and pedestrian-friendly a few destination station areas with high employment development. densities. The primarily low-density form is punctuated by Interchange area urban form: lower residential densities high-density employment station areas (like those found and employment land uses; high-capacity, high-speed in a CBD) where transit riders who accessed the transit street designs. line by car can walk to their destinations. Implement a · Transit-Oriented Station Access: Transit stations are hierarchical, high-capacity street network that encourages designed to favor nonautomobile access. Trip origin high-speed automobile travel throughout the corridor. stations are placed as far as possible from the freeway and Interchange area urban form: low-density residential its off-ramps to reduce the amount of automobile traffic and employment land uses; high-capacity, high-speed in the station-area neighborhoods as well as the negative street designs. externalities of the freeway facility itself. Stations should be · Automobile-Oriented Station Access: The transit line's placed as far from freeway interchanges as possible to avoid non-CBD stations are designed to favor automobile access. automobile/nonautomobile conflicts and encourage non- Trip origin stations are placed close to the freeway interchange automobile access to stations. ramps to facilitate quick, easy transfer from the freeway to the · Corridor-Wide Jobs-Housing Balance: Ideally, travel flows transit line; trip destination stations (such as those serving a through the corridor are relatively balanced, so the capacities CBD) are placed far away to promote pedestrian movements of the freeway and transit line are maximized. Balanced within employment centers. Origin stations have ample travel flows can be achieved by a corridorwide jobs-housing park-and-ride capacity and a high-capacity street network balance, where no station or group of stations is only a nearby to handle the peak-period demand at stations from destination (such as a CBD) or a residential trip generator. park-and-riders and pick-up/drop-off activities.