Transit Street Design Guide
260
Transit Street Design Guide
260Hardcover
-
SHIP THIS ITEMTemporarily Out of Stock Online
-
PICK UP IN STORECheck Availability at Nearby Stores
Available within 2 business hours
Related collections and offers
Overview
Product Details
| ISBN-13: | 9781610917476 |
|---|---|
| Publisher: | Island Press |
| Publication date: | 04/14/2016 |
| Pages: | 260 |
| Product dimensions: | 8.20(w) x 10.80(h) x 0.70(d) |
About the Author
Read an Excerpt
Transit Street Design Guide
By Island Press
ISLAND PRESS
Copyright © 2016 National Association of City Transportation OfficialsAll rights reserved.
ISBN: 978-1-61091-747-6
CHAPTER 1
Introduction
Key Principles
Why Transit Streets Matter
Designing to Move People
Reliability Matters
Service Context
Transit Route Types
Transit Frequency & Volume
Transit is returning to its central place in the life of cities. With more people using buses, streetcars, and light rail than ever before, our street design paradigm is shifting to give transit the space it deserves. People are choosing to live, work, and play in walkable neighborhoods, and cities are prioritizing highly productive modes like transit as the key to efficient, sustainable mobility for growing urban populations. Transit agencies and street departments are working together to create streets that not only keep buses and streetcars moving, but are great places to be. Cities are extending light rail systems, investing in streetcar lines, and creating new rapid bus lines at a stunning pace, with ridership growing even faster in city centers. Transit agencies are rethinking their networks to serve neighborhoods at a high level all day, not just at commute times, while bike share and active transportation networks make it even easier to not only reduce driving, but to avoid the expense of owning a car.
At the heart of these changes is the need for cities to grow without slowing down. Transit is a key that unlocks street space, bringing new opportunities to create streets that can move tremendous numbers of people and be enjoyed as public spaces at the same time.
Cities around the country and around the world are finding new ways to create these places. To codify and advance best practices in transit design, the National Association of City Transportation Officials has brought together practitioners and leaders from the transit and street sectors to develop the Transit Street Design Guide. This new framework for designing transit corridors as public spaces will help cities and their residents work together to create the streets that are the foundation of a vibrant urban future.
Key Principles
BETTER STREETS, BETTER SERVICE
Making transit work in cities means raising the level of design across the entire street network. Cities can take the lead on transit, creating dedicated lanes and transitways, designing comfortable stops and stations, and coordinating action with transit agencies on intersections and signals.
Transit-first street design also means treating walking as the foundation of the transportation system. Ultimately, the efficiency of transit creates room for public space, biking and walking networks, and green infrastructure — allowing cities to remake their streets as safer, more sustainable public spaces.
TRANSIT CREATES URBAN PLACES
Cities and transit are deeply linked. In vibrant, bustling cities, people are on the move, and transit plays an indispensable role in keeping them moving. Walkable urban places have a critical mass of people and activities that support and rely on transit to connect them to other places. Cities can strengthen this synergy by creating transit streets: places that move people.
With the majority of US residents preferring walkable, bikeable urban environments, the value of better transit accrues not only to existing transit passengers and newly attracted ones, but to people who will decide where to live and start businesses — in which neighborhood, city, or region — based on the availability of transit-served walkable neighborhoods. These location decisions affect the competitiveness of the entire metropolitan area and justify transit- first policies in street design and investment.
A MOBILITY SERVICE FOR THE WHOLE CITY
Making it possible to quickly and reliably go anywhere by transit is a way for cities to significantly improve quality of life. A transit system designed as a mobility service focuses on its value to the rider, providing prompt, seamless, and safe connections to where people want and need to go. A public transit-based mobility system, open to people of all ages and abilities, is fundamentally more equitable than one based primarily on private vehicles.
A crucial complement to the transit network is a suite of flexible, convenient, and affordable mobility choices — walking, bicycling, shared mobility, and on-demand rides — that, together with fixed-route transit, allow residents to avoid the costs of car ownership and make proactive decisions about each trip they take.
GROWTH WITHOUT CONGESTION
Transit streets allow growth in economic activity and developmental density without growth in traffic congestion by serving more people in less space. Transit is most productive for a city and most effective for riders when a large number of people want to travel along one street, but these types of streets are inherently prone to automobile congestion, with unreliable travel times when the most people need to travel.
Streets designed for rapid transit reverse this equation, making transit trips fastest on streets with high travel demand, where frequency is greatest. A public transit-based mobility system benefits everyone in a city, whether or not they choose to ride transit, as people using transit and private vehicles alike can access more destinations in the same amount of time after transit has been improved and density increased.
SAFE MOVEMENT AT A LARGE SCALE
With transit's order-of-magnitude safety advantage over private automobiles, promoting transit is integral to policies that seek sustained improvements in pedestrian, bicyclist, and vehicle occupant safety. Transit mode share and transit-supportive infrastructure are directly correlated to lower traffic fatality rates.
Improving transit does not mean creating speedways, since higher top speeds have little benefit for transit on city streets. Transit streets designed with people in mind are safe places to walk and bike, and transit improvements go hand in hand with better pedestrian access, safer crossings, and more enjoyable public space.
PERMANENT ECONOMIC BENEFITS
Transit streets save both time and money, making frequent service into a financially sustainable proposition and setting off a virtuous cycle of more riders, more service, and more street space for people. Beyond the well-documented local economic benefits of transit-friendly street design, savings are accrued by transit agencies, which can provide mobility to more people at a lower cost, as well as to passengers who can access more destinations faster. And since transit supports higher-value, more compact development, it is a more fiscally sustainable investment than highway infrastructure. These savings are good for businesses and residents along a transit corridor and far beyond.
Why Transit Streets Matter
High-quality transit allows a city to grow without slowing down. When prioritized, transit has the potential to stem the growth of vehicle congestion, provide environmentally efficient and responsible transportation, and reduce both personal mobility expenses and overall public infrastructure expenses. And transit that can be relied on makes it possible to build walkable urban places — the kinds of places that city residents increasingly demand.
Accomplishing all of this requires that cities set priorities and make investments, both in transit service itself and in the streets on which transit operates. Much of the transit street design challenge lies in aligning the priorities and demands of city departments with those of transit operators, and in demonstrating the value of investments and dedicated street space to city residents and leaders. Balancing multiple modes in a limited right-of-way calls for a considered approach, with short-term successes building to long-term gains.
Designing to Move People
Transit streets are designed to move people, and should be evaluated in part by their ability to do so. Whether in dense urban cores, on conventional arterials, or along neighborhood spines, transit is the most spatially efficient mode.
Traditional volume measures fail to account for the entirety of functions taking place on urban streets, as well as the social, cultural, and economic activities served by transit, walking, and bicycling. Shifting trips to more efficient travel modes is essential to upgrading the performance of limited street space.
Using person throughput as a primary measure relates the design of a transit street to broader mode shift goals.
While street performance is conventionally measured based on vehicle traffic throughput and speed, measuring the number of people moved on a street — its person throughput and capacity — presents a more complete picture of how a city's residents and visitors get around. Whether making daily commutes or discretionary trips, city residents will choose the mode that is reliable, convenient, and comfortable.
Transit has the highest capacity for moving people in a constrained space. Where a single travel lane of private vehicle traffic on an urban street might move 600 to 1,600 people per hour (assuming one to two passengers per vehicle and 600 to 800 vehicles per hour), a dedicated bus lane can carry up to 8,000 passengers per hour. A transitway lane can serve up to 25,000 people per hour per travel direction.
Reliability Matters
Unlocking the enormous potential of transit requires active measures to make trips take less time. To achieve this, the Transit Street Design Guide details street design strategies to improve transit reliability and reduce overall travel times.
Transit service that is reliable and efficient brings value to people and cities, but slow and inconsistent service will discourage passengers and jeopardize local benefits. If a trip takes significantly longer by transit than by other modes, or if actual trip time ranges so widely as to be unpredictable, people may choose not to take transit and cities will miss out on opportunities to reduce congestion and spur development.
For urban transit, getting to a destination faster means removing sources of delay rather than raising top travel speeds. The most significant sources of transit delay are related to both street design and transit operations, calling for coordinated action by transit and street authorities.
TRAFFIC & INTERSECTION DELAY
In mixed traffic, transit is limited by prevailing traffic conditions, and will be delayed by all the factors that delay the cars it shares space with. Time spent waiting for signals or slowing for stop signs, known as intersection delay or traffic control delay, increases as traffic volume nears the capacity of the street, and as cross streets are more frequent or reach their own capacity. Providing transit lanes (see page 110) and using signal strategies (see page 149) can help cut travel times by half, with the greatest benefits made available by using transitways (see page 126). While these levels of priority stop short of grade-separated facilities, they can be the foundation of every city's transit design toolbox, and are inherently adaptable to a variety of street conditions.
While signal delay is relatively easy to address through active TSP if traffic queues are short, signals with long or variable queues can add up to very long delays for buses and streetcars in mixed-traffic conditions. Time spent slowly approaching red signals or stop signs in heavy traffic can also contribute to overall delay.
Unreliable travel times are a major issue for transit operations because short delays can quickly snowball as more passengers try to board a late-arriving vehicle. Missing one green signal can cause a bus or streetcar to fall behind enough to delay the transit vehicle behind it.
DWELL TIME
Dwell time related to passenger boarding and payment is a large component of total travel time on productive routes, especially in downtowns and destination areas. Level or near-level boarding (see page 64), multi-door boarding and advanced payment options (see page 182), and better passenger information can cut dwell time in half or more. Stop consolidation also reduces the amount of time spent dwelling at stops.
Savings from Transit Improvements
TIME IN MOTION: ACCELERATION, MERGING, AND ROUTE DIVERGENCE
Acceleration, deceleration, and door operation time approaching or leaving a stop can add 15–30 or more seconds per stop. Consolidating from stops to stations (see page 181) and introducing rapid services (see page 10) can dramatically reduce this time expenditure.
For buses in particular, merging into or re-entering the flow of general traffic after a conventional curbside pull-out stop is a perennial source of delay. Reduce this delay by providing in-lane stops and stop-related signal treatments (see Signals & Operations on page 149, and Stop Placement & Intersection Configuration on page 60), or by enforcing a yield-to-bus law.
Circuitous routes and turns can be time consuming for transit operators and confusing for passengers, often adding significantly to travel time. Keeping transit lines simple and direct serves to minimize this delay, improving transit travel times. While this may increase the time spent walking to a stop, it can benefit overall trip times. Evaluate any changes based on a walking network model and transit travel times.
Responding to development
PASSENGER ACCESS AND WAIT TIME
In addition to on-board transit time, a passenger's trip time also includes time spent walking to a stop, waiting for transit to arrive, making any transfers, and accessing a destination. Since passengers place 2.5 times more value on a shorter wait than on a shorter amount of time spent in motion or a shorter walk to transit, a small improvement in wait time can provide a larger benefit to passengers and a greater boost to ridership than a similar improvement in speed.
Reliability affects how passengers perceive wait times. If wait time and travel time vary significantly, or are routinely much longer than the scheduled time, passengers build this time into their trips, and transit becomes less useful for them.
Transit and street design can make wait time valuable to passengers by providing comfortable waiting areas at stops (see Stations & Stops, page 57), by providing real-time information to reduce start-of-trip wait times, and by reducing the time needed for transfers through network design (see Transit System Strategies, page 175). Quality urban street design can make walking to a transit stop a positive feature of transit trips.
UNLOCKING OPERATIONAL EFFICIENCIES
Addressing the main sources of transit delay has two related benefits. It shortens door-to-door time for a passenger trip, improving the competitiveness of transit. It also reduces the time and cost of each transit vehicle's run, enabling a transit agency to provide more frequent service to each stop with the same number of vehicles and drivers. In this context a small travel time savings is a large cost savings.
Buses in mixed traffic are susceptible to a downward service spiral, in which increased congestion — exacerbated over the long term by designing streets primarily to accommodate private motor vehicles — results in lower ridership and revenue, resulting in service cuts and lower ridership and revenue.
This cycle can be reversed by improving on-street transit travel times. Shorter travel time allows transit operators to run more frequent service, with more runs per hour using the same number of vehicles and drivers. Greater frequency and shorter trip time yields higher ridership, raising revenue and permitting still greater service frequency.
(Continues...)
Excerpted from Transit Street Design Guide by Island Press. Copyright © 2016 National Association of City Transportation Officials. Excerpted by permission of ISLAND PRESS.
All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
Excerpts are provided by Dial-A-Book Inc. solely for the personal use of visitors to this web site.