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

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36 This chapter offers insights into the key tradeoffs that need to be made when planning, designing, building, and operating a new paradigm corridor. Close scrutiny of existing multi- modal corridors suggests that the effectiveness of a transit line within a multimodal corridor depends on its design and the design of its adjacent freeway. The new paradigm offers insights into the competition between freeways and transit and how this competition can be structured to effectively carve out travel market niches in which each mode can thrive. This chapter investigates the alternatives that should be considered when planning a new paradigm corridor project. Multimodal Corridor Design and Operational Tradeoffs A new paradigm corridor is planned, designed, and operated to ensure an even playing field for competition between transit and freeway by segmenting the corridor’s travel markets. Segmented corridor markets—where transit and freeway are each given a distinct travel market segment—can be encour- aged by the deliberate selection of combinations of planning, design, and operational corridor components. These compo- nents are discussed here as tradeoffs between performance and design characteristics that help frame the discussion of the new paradigm. Although these tradeoffs should be considered when plan- ning a multimodal corridor, a successful new paradigm cor- ridor uses the sum total of these tradeoff choices as building blocks to yield a corridor that segments its travel market, giving both transit and freeway an advantage in serving a submarket. Segmented multimodal corridor markets can generally be classified as having either a transit or automobile orientation. The following section begins by describing transit and automobile corridor orientation, followed by a discussion of the building block tradeoffs that contribute to them and ensure segmented travel markets. Transit Versus Automobile Corridor Orientation The tradeoffs between freeways and transit lines involve the facilities themselves as well as the corridors they inhabit. The orientation of a corridor’s urban form (including land uses and urban design) and the design of the transit and freeway facil- ities are important elements determining the relative success of the corridor’s transportation facilities (see Figure 4-1). Transit-oriented corridors are designed to maximize non- automobilemobile access to land uses and transit stations. Land uses are generally high density with minimal parking. Walking is encouraged through the provision of dense, grid street networks with wide sidewalks and streets designed for pedestrian friendliness and moderate traffic speeds. The transit system and its surrounding circulation systems are all designed to maximize access to transit stations by all modes of travel, especially pedestrians. Automobile-oriented corridors favor automobile mobility over nonautomobile station access. This typically leads to a corridor with low-density, dispersed land uses that are difficult for pedestrians, bicycles, and transit to traverse while auto- mobiles can effectively, safely, and comfortably access these destinations. The freeway and its surrounding circulation systems are designed to maximize automobile throughput (capacity), automobile travel speeds, and/or automobile access to corridor land uses. If transit service exists at all in automobile-oriented corridors it generally supports auto- mobile circulation. Transit stations or stops are designed to maximize automobile access and parking. Park-and-ride lots dominate the immediate station environments, and high- capacity road connections between station areas and the free- way encourage peak-period commuters to reduce freeway congestion by parking their cars and transferring to transit. Few corridors are purely transit- or automobile-oriented; most have a mixture of automobile- and transit-oriented elements. These hybrid types can be placed somewhere along C H A P T E R 4 Managing Multimodal Tradeoffs— Structuring Corridor Competition and Integration

37 the multimodal corridor continuum shown in Figure 4-1— a subset of the corridor continuum. Under this framework, we can envision a range of multimodal corridor types. At one extreme, multimodal transit-oriented corridors generally emphasize nonautomobile access to land uses and transit stations, but still provide sufficient parking and freeway-to- transit intermodal transfer capabilities to allow and encourage transfers between modes. At the other end of the spectrum, multimodal automobile-oriented corridors emphasize auto- mobile access to relatively dispersed land uses and to the freeway. New paradigm corridors require deliberate mixtures of these components to create segmented travel markets favoring each mode. The critical choices made for a multimodal corridor’s design revolve around the advantages and disadvantages given to each mode. Often, tradeoffs must be made between modes. An advantage given to transit may come at the expense of the performance of the freeway and vice versa. The degree to which a corridor has optimized combinations of transportation services and land uses will depend on the degree to which it was intentionally and effectively planned and managed that way. Therefore, the multimodal corridor continuum is best under- stood in relation to what we refer to later in this chapter as the “multimodal planning continuum” (see Figure 4-7). Key New Paradigm Corridor Tradeoffs The selection of new paradigm corridor design and operat- ing characteristics should be done within the context of how these choices will affect the tradeoffs in performance among corridor modes. These tradeoff choices will, in turn, determine corridor orientation and market segmentation. The follow- ing is a list of critical tradeoffs that describe and determine the relative success of a new paradigm corridor: • Transit corridor accessibility versus operating speed • Freeway accessibility versus operating speed • Freeway capacity versus transit ridership • Transit-oriented versus automobile-oriented urban form • Local access versus intermodal transfer stations • In-median and adjacent versus offset freeway alignment • Supplementary versus complementary transit and freeway service • Fixed versus flexible transit routing • Incremental versus concurrent corridor planning ap- proaches Transit Corridor Accessibility Versus Operating Speed To a large extent, both transit coverage and operating speeds are a function of the number of stations provided on the transit line. The more stations per mile of transit line (that is, the higher the density of stations) the more area the transit line will serve and the more accessibility transit riders will have to corridor land uses. However, the more stations a transit line has, the slower the speed of the transit vehicles will be and the more difficult it will be for transit to compete with the adjacent freeway in terms of travel times. The illustrations in Figure 4-2 show how a high frequency of stations and a circuitous alignment can increase transit accessibility to local, corridor land uses at the expense of operating speeds, while low station frequencies and straight alignments can offer higher operating speeds at the expense of transit accessibility to corridor land uses. Transit lines generally are designed to either attract local, short-haul riders or long-haul, “through” riders. Transit generally attracts local riders when the line and its surrounding land uses are coordinated to provide high accessibility, while it attracts through passengers when it emphasizes fast operating Oriented Access to Individual Multimodal Corridor Continuum Corridor Continuum Multimodal Transit- Objective: Emphasize Non- Auto Access to Transit Stations & Activity Centers Multimodal Auto- Oriented Objective: Emphasize Auto Access to Employment Centers & Transit Stations Transit-Oriented Objective: Max. Non- Auto Access to Transit & Activity Centers Auto-Oriented Objective: Max. Auto Land Uses Figure 4-1. The corridor and multimodal corridor continuums.

38 speeds. Table 4-1 suggests how this tradeoff can serve the purposes of developing a new paradigm corridor to have market segmentation and an optimized corridor orientation. Freeway Corridor Accessibility Versus Operating Speed Freeway systems with high interchange frequencies (that is, a large number of interchanges per mile) and circuitous right- of-way alignments generally provide high levels of accessibility to local, corridor land uses at the expense of operating speeds. These facilities are often more congested because more access points and curves along a freeway tend to slow traffic. Figure 4-3 shows how a high frequency of interchanges and a circuitous alignment can increase freeway accessibility to local, corridor land uses at the expense of operating speeds, while a low frequency of interchanges and straight alignments offer higher operating speeds at the expense of freeway acces- sibility to corridor land uses.1, 2 Similar to transit lines, freeways are generally designed to attract either local short-haul patrons or long-haul “through” patrons. Freeways tend to attract local trips when the freeway and its surrounding land uses are coordinated to provide high area coverage, while it attracts through (long-haul) passengers when the facility and its corridor alignment emphasize high operating speeds. Table 4-2 suggests how this tradeoff can serve the purposes of developing a new paradigm corridor to have market segmentation and an optimized corridor orientation. Freeway Capacity Versus Transit Ridership Performance On transit lines that directly compete with freeways, rider- ship can suffer when freeway capacity is maximized. If ample freeway capacity is available—for example, when a freeway has enough lanes to handle peak-period traffic demand— freeway travel times will be short because of lower congestion levels and transit will not be an attractive alternative to driving. Table 4-3 suggests how this tradeoff can serve the purposes of developing a new paradigm corridor to have market segmen- tation and an optimized corridor orientation. Transit-Oriented Versus Automobile-Oriented Urban Form Urban form describes both the land uses and urban design qualities of an urban environment. Transit-oriented urban form is typically defined as high-density, mixed-use, pedestrian- friendly land uses close to transit stations. Nonautomobile- motive circulation is encouraged using dense, grid street networks and other design measures to slow automobile speeds. Automobile-oriented urban form has lower density, separated land uses with street pattern and urban design qualities intended to give priority to automobile circulation. Table 4-4 suggests how this tradeoff can serve the purposes of developing High Access/Low Speed Transit Line Low Access/High Speed Transit Line Figure 4-2. Transit corridor accessibility versus operating speed designs. 1AASHTO (2004) AASHTO Green Book: A Policy on Geometric Design of Free- ways and Streets, 5th Edition. 2Skabardonis, A., et al. Low-Cost Improvements for Recurring Freeway Bottle- necks. NCHRP Project 03-83, anticipated publication in 2010. Transit Corridor Accessibility Transit Operating Speed Market Segmentation Local/Short-haul trips Regional/Long-haul trips Corridor Orientation Transit-oriented Automobile-oriented Table 4-1. Transit corridor accessibility versus operating speed tradeoff outcomes.

a new paradigm corridor to have market segmentation and an optimized corridor orientation. Local-Access- Versus Intermodal-Transfer-Oriented Stations Local-access-oriented stations are designed to accommodate and attract patrons from nearby neighborhoods, while inter- modal transfer stations are designed to attract patrons arriving by car or bus transit from beyond the station’s local neighbor- hood. Local-access stations provide excellent pedestrian, bicycle, and local circulator shuttle service access to station entrances, unencumbered by park-and-ride lots, kiss-and-ride drop-off areas, and bus terminal facilities. Intermodal-transfer-oriented stations attract automobile- and bus-to-transit transfer patrons by providing ample High Access/High Congestion Freeway Low Access/Low Congestion Freeway Figure 4-3. Freeway corridor accessibility versus operating speed designs. Freeway Corridor Accessibility Freeway Operating Speed Market Segmentation Local/Short-haul trips Regional/Long-haul trips Corridor Orientation Automobile-oriented Transit-oriented Table 4-2. Freeway corridor accessibility versus operating speed tradeoff outcomes. Freeway Capacity Transit Ridership Performance Market Segmentation Freeway dominates corridor travel Transit has a potential to serve a secure travel market Corridor Orientation Automobile-oriented Transit- or Automobile- oriented Table 4-3. Freeway capacity versus transit performance outcomes. Transit-Oriented Urban Form Automobile-Oriented Urban Form Market Segmentation Nonmotorized transit station access Automobile transit station access Corridor Orientation Transit-oriented Automobile-oriented Table 4-4. Transit- versus automobile-oriented urban form tradeoff outcomes. 39

40 park-and-ride lots, quick and effective kiss-and-ride drop-off facilities, and efficient, high-capacity bus terminal facilities to handle intermodal transfers. Intermodal stations are often located close to freeway ramp touchdown points, allowing quick freeway-to-transit intermodal transfers. Table 4-5 sug- gests how this tradeoff can serve the purposes of developing a new paradigm corridor to have market segmentation and an optimized corridor orientation. In-Median and Adjacent Versus Offset Freeway Alignment The alignment of the transit and freeway facilities has impli- cations for the patronage of each mode as well as the costs of constructing them. Figure 4-4 illustrates the range of hori- zontal multimodal corridor alignments. In-median and adjacent alignments offer the greatest poten- tial for cost-savings in land acquisition and construction for the transit line (assuming it is the second facility built in the corridor after the freeway) because they can take advantage of any surplus right-of-way land in or next to the freeway. Offset transit lines must often piece together vacant or otherwise available land to create a new right-of-way, potentially incur- ring significant costs. The adjacent alignment/offset stations option is a hybrid variant with potential to take advantage of some of the cost savings possible from adjacent or in-median alignments while also avoiding the pedestrian and transit access impediments Local Access Intermodal Transfer Market Segmentation Nonmotorized transit station access Automobile transit station access Corridor Orientation Transit-oriented Automobile-oriented Table 4-5. Local access versus intermodal transfer tradeoff outcomes. u p to 1/ 2- m i. Offset Alignment Adjacent Alignment In-Median Alignment LEGEND Transit Line Transit Station Freeway Freeway Interchange u p to 1/ 2- m i. Adjacent Alignment /Offset Stations Figure 4-4. The range of horizontal multimodal corridor alignments.

41 of these approaches. By running the transit line primarily in the freeway ROW while locating the stations as far as possible from the freeway, benefits for pedestrian, bicycle, and feeder transit access to the stations can be realized, but often at the expense of transit operating speeds and travel times along the corridor due to the circuitous route the transit line must follow. The range of possible corridor horizontal alignments also has significant performance implications. In-median alignments have the most potential for operational conflicts between the transit stations and the freeway and its inter- change ramps. The freeway is a physical barrier to pedestrians and bicyclists accessing both adjacent and in-median stations. Traffic going to and from the freeway via its interchange ramps pose a safety hazard to pedestrians and bicycles attempting to access the stations and tend to make a transit-unfriendly environment. Transit lines offset from their freeway neighbors can operate in greater isolation from the freeway and its automobile traffic, potentially taking advantage of a more pedestrian-friendly environment. As a result, adjacent or in-median transit lines must depend more on automobile and bus access to their stations, potentially limiting the ridership performance of their systems. In-median and adjacent transit alignments also have performance implications for freeways, since the traffic associated with station access can disrupt the smooth oper- ation of freeway interchange ramps and reduce the carrying capacity of the freeway itself. Table 4-6 suggests how this tradeoff can serve the purposes of developing a new paradigm corridor to have market seg- mentation and an optimized corridor orientation. Multimodal Coordination: Supplementary Versus Complementary Transit and Freeway Services A truly multimodal corridor is designed to maximize the intermodal relationships between the freeway and transit facilities in the corridor. Ideally, either automobile-to-transit or nonautomobile-to-automobile transfers will be seamless and as effortless as possible. In this way, transit and freeway systems complement each other, providing a combined level of service for corridor trips that exceeds the summed capacity and performance of its component parts. However, the proximity of transit and freeways in multi- modal corridors often cause operational conflicts for both modes. These conflicts can be minimized by effectively dividing the corridor’s travel market into long- and short-haul trips and then designing the transit line and the freeway to cater exclusively to one or the other. Although it is understood that traditionally the spacings of freeway interchanges are keyed to street patterns and design standards, while the spacings of rapid transit are keyed to bus routes, development densities, and street patterns, the effects of multimodal coordination can affect operations and patron- age, without respect to the original intentions of the systems’ designers. Multimodal corridor transit and freeway facilities are gen- erally either coordinated in a supplementary or complementary fashion. • Supplementary coordination means that the additional infrastructure in terms of lanes, track, ramps, and stations will supplement the capacity of the corridor, increasing access and mobility. Supplemental effects improve the corridor capacity additively. • Complementary coordination results from the fact that the transit and freeway components of the corridor may exhibit different though complementary characteristics, outcomes, and benefits. Complementary benefits would occur from the integration of modes within a multimodal corridor. Transit and freeway facilities can coexist in the same corridor, but may not work in a coordinated fashion. The various modes in a corridor might be coordinated through a common payment system, a traveler infor- mation system with comparative travel times by mode, or a coordinated, real-time congestion management system that adjusts the capacity and service deployments of one mode to compensate for the capacity constraints of another. Corridors that have either a combination of long station spacings and short interchange spacings, or the opposite, offer complementary travel services in a multimodal corridor and tend to carry more total passengers. So-called supplementary corridors that have similarly spaced stations and interchanges will compete directly with each other for the same corridor trips, and performance of the entire corridor suffers as a result. In-Median/Adjacent Alignment Offset Alignment Market Segmentation Intermodal transfers/Transit as congestion relief to freeway High level of segmentation possible Corridor Orientation Automobile-oriented Transit-oriented Table 4-6. In-median and adjacent versus offset alignment tradeoff outcomes.

Analysis suggests that corridors will carry the most total passengers (transit riders and freeway passengers) if they are designed with complementary coordination, and a combi- nation of either a transit-oriented urban form pattern and transit-oriented station access services, or automobile-oriented urban form and automobile-oriented station access. Based on these findings, we further propose three multi- modal coordination configurations (illustrated in Figure 4-5): transit-oriented complementary, automobile-oriented com- plementary, and supplementary. A corridor with transit-oriented complementary coordina- tion has long interchange spacings on its freeway component and relatively short station spacings on its transit line. This provides a high level of local accessibility and slower speeds for transit, and higher speeds and lower accessibility for auto- mobiles via the freeway. A corridor with automobile-oriented complementary coordination has long station spacings on its transit facility and relatively short interchange spacings on its freeway com- ponent. This provides a low level of local accessibility and higher speeds for transit, and lower speeds and higher acces- sibility for automobiles via the freeway. Table 4-7 suggests how this tradeoff can serve the purposes of developing a new paradigm corridor to have market seg- mentation and an optimized corridor orientation. Fixed Versus Flexible Transit Routing One of the most important advantages automobiles have over traditional transit services is their flexibility—wherever roads go, cars can go. Fixed-rail transit vehicles only go where tracks are installed. This means fixed-rail transit operates at a 42 Supplementary Transit-Oriented Complementary Auto-Oriented Complementary Figure 4-5. Multimodal coordination hypothetical complementary and supplementary corridors. Supplementary Automobile-Oriented Complementary Transit-Oriented Complementary Market Segmentation Low levels of segmentation Freeway: Local/Short- haul trips Transit: Regional/Long- haul trips Transit: Local/Short-haul trips Freeway: Regional/Long- haul trips Corridor Orientation Automobile-oriented Automobile-oriented Transit-oriented Table 4-7. Multimodal coordination tradeoff outcomes.

disadvantage vis-à-vis a freeway because automobiles can cover much more territory within the same corridor. However, BRT is not dependent on fixed right-of-way infrastructure and therefore offers flexible routing as well as the carrying capacity and speed advantages of fixed rail. BRT operating in separate facilities in or alongside a freeway median may enter and leave the freeway at selected locations, and distribute to other areas. With rail lines, this usually requires a transfer to buses. The flexible routing capabilities of BRT are illustrated in Figure 4-6. However, just as BRT can offer some of the routing flexibil- ity advantages similar to automobiles, it can also suffer from some of the same disadvantages that automobiles face. Auto- mobiles can operate at a disadvantage to fixed rail and exclu- sive lane BRT transit services because they are slowed by sig- nal systems and are subject to congestion. Therefore, while flexibility of routing can be an advantage for BRT, it can also lower transit’s quality of service due to signal and congestion delays when not running exclusively in a dedicated lane. Table 4-8 suggests how this tradeoff can serve the purposes of developing a new paradigm corridor to have market seg- mentation and an optimized corridor orientation. Planning Multimodal Corridors: Concurrent Versus Incremental Approaches To understand how a multimodal corridor functions and its relative success, it is necessary to understand something about its history and the process by which it was planned, 43 Source: Courtesy Washington State Department of Transportation and IBI Group, I-405 South Corridor Bus Rapid Transit Pre-Design, Final Report. Figure 4-6. Two routing alternatives for the proposed I-405 South Corridor Bus Rapid Transit System for the Puget Sound Region illustrates the flexible routing capabilities of bus rapid transit. Fixed Transit Routing Flexible Transit Routing Market Segmentation High level of segmentation possible Intermodal transfers/Transit as congestion relief to freeway Corridor Orientation Transit-oriented Automobile-oriented Table 4-8. Fixed versus flexible transit routing tradeoff outcomes.

designed, and constructed. Under this framework, an effort is made to account for how a corridor is given or has taken on multimodal features. Here, we propose a continuum that distinguishes between the degree to which a multimodal cor- ridor has developed as a result of an explicit intention or is the incidental result of a series of planning and investment decisions over time. To the degree that the multimodal features of facilities— transit and freeways—are designed by intention and at the same time, we refer to them as concurrently planned. To the degree that the multimodal features of corridors arise over time, organically or as a result of incremental measures, they are referred to as incrementally planned (see Figure 4-7). At one end of this continuum is the concurrently planned multimodal corridor. A hypothetical, pure example of such a corridor is one where all transportation facilities were planned, designed, and built at the same time and in a coordinated fashion. In this way, the full performance potential of the multimodal system can be realized, with each mode both supplementing and complementing the others in a coordinated whole. The surrounding land use context within the corridor could also develop in response to this coordinated multimodal system, ideally providing an optimized transportation and land use interface. At the other end of the continuum is the incrementally planned multimodal corridor. Here, each corridor component has been designed and built in an incremental fashion. In this extreme case, there will be few if any functional connections between the various modes running in the corridor—transit, freeway, pedestrian, and bicycle facilities will all operate relatively independently with few transfers between systems and in an uncoordinated fashion. Gradually, incremental (and often inexpensive) connections will be made between the modes to create a more cohesive and coordinated multi- modal corridor system. Shuttles may be set up to run between freeway park-and-ride lots and transit stations to encourage intermodal transfers. Traffic information management sys- tems may be installed along the freeway to provide motorists with comparative travel times for freeway and transit to reach their corridor destinations, encouraging peak-period mode shifting. Sidewalks, paths, and bicycle routes might be added to the existing surface street network to encourage more non- automobile circulation along the corridor and non-automobile connections between modes. Another important option along this continuum is the transit retrofit approach. Located near the incrementally planned side of the scale, a transit retrofit project involves the addition of a transit line to a pre-existing freeway facility (such as in the case of Denver’s T-REX/I-25 corridor) and its surrounding corridor. This approach is distinguished by the high costs involved in redesigning and reconstructing the freeway facility (or its immediate environment) relative to the purely opportunistic/incremental approach described above, but its costs are relatively low compared to the inten- tionally planned system described above. Typically, the designs of capital-intensive transit systems (historically rail but increas- ingly bus rapid transit) are driven more by short-term cost- minimization through retrofitting than long-term ridership development-maximization principles. Also falling in the midrange of the continuum are multi- modal facilities where the plans for and the reality of their operations and constructions diverge over time. Planned facil- ities can become obsolete, or conflicting plans developed by different stakeholders (for example, transit agencies, freeway departments, or local land use authorities) can result in sub- optimal operations and outcomes. Table 4-9 suggests how this tradeoff can serve the purposes of developing a new paradigm corridor to have market seg- mentation and an optimized corridor orientation. Summary and Conclusions The key to planning, designing, building, and operating a successful new paradigm multimodal corridor is to provide segmented, distinct travel markets within the corridor that each mode can serve. Segmented multimodal corridor markets can 44 Planned and Built at Different Times Incremental Approach to Coordination High Potential for Cost Savings Planned & Constructed at Same Time Highly Coordinated or Combined Agencies High Potential Aggregate Cost Savings High Potential for Complementary Performance Incrementally Planned Concurrently Planned Figure 4-7. The multimodal planning continuum.

generally be classified as having either a transit or auto- mobile orientation. This chapter identifies the following tradeoffs that can be made when planning a new paradigm corridor: • Transit corridor accessibility versus operating speed • Freeway accessibility versus operating speed • Freeway capacity versus transit ridership • Transit-oriented versus automobile-oriented urban form • Local access versus intermodal transfer stations • In-median and adjacent versus offset freeway alignment • Supplementary versus complementary transit and freeway service • Fixed versus flexible transit routing • Incremental versus concurrent corridor planning approaches 45 Concurrently Planned Incrementally Planned Market Segmentation High level of segmentation possible Intermodal transfers/Transit as congestion relief to freeway Corridor Orientation Transit-oriented Automobile-oriented Table 4-9. Intentional versus incremental transit routing tradeoff outcomes.