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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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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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· 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.
