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Congestion

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  • Airport

Manage Flight Demand or Build Airport Capacity?

Megan S. Ryerson and Amber Woodburn

Airports can manage air traffic congestion in two ways: 1) add infrastructure or 2) manage flight demand. The environmental and economic implications of these options, however, often conflict. New runways have significant financial and environmental costs, but they can also stimulate economic development and increase a city’s appeal to businesses. Managing demand saves construction costs and encourages fuel efficiency but may limit opportunities for regional growth. Our research finds that airports in the US underestimate or ignore these tradeoffs and, as a result, frequently fail to consider managing demand as an alternative to building new runways.

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A Bathtub Model of Downtown Traffic Congestion

Richard Arnott

William Vickrey is the “father of congestion pricing” and a Nobel Laureate in economics. While watching the ebb and flow of traffic from his Manhattan office, he developed a hypothesis that the dynamics of rush-hour traffic have the same properties as water flowing into and out of a hypothetical bathtub.

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Carmageddon in Los Angeles: The Sizzle and the Fizzle

Brian D. Taylor and Martin Wachs

“Carmageddon” refers to the horrific traffic jams predicted when a bridge reconstruction project in Los Angeles required closing 10 miles of the Interstate 405 freeway on two weekends. The closed freeway through the Sepulveda Pass between West Los Angeles and the San Fernando Valley is one of the most heavily traveled arteries in the world, with more than half a million vehicles passing through on a typical summer weekend. Traffic from the closures was predicted to back up for miles and spill onto local streets, severely congesting some parts of Los Angeles. Download the PDF.
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Carmageddon or Carmaheaven? Air Quality Results of a Freeway Closure

Arthur Winer, Yifang Zhu, and Suzanne Paulson

Air quality researchers have recently shifted their focus from regional smog, which has been reduced dramatically over the past 40 years, to the more localized impacts of vehicle emissions near roadways. Numerous studies have linked traffic-related air pollution to a broad range of adverse health outcomes. Concern has focused on black carbon, particles less than 2.5 microns in diameter (PM2.5), and ultrafine particles less than 100 nanometers in diameter, small enough to penetrate cell walls and cross the blood-brain barrier. These pollutants may be carried up to 300 meters downwind of major roadways during the day, and more than 2,000 meters downwind in the early morning hours, affecting large populations in major urban centers. By addressing these pollutants, policies to reduce traffic, congestion, and emissions can improve air quality and health. Download the PDF.
Categories: ACCESS 44, Spring 2014|Tags: , |
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SFpark: Pricing Parking by Demand

Gregory Pierce and Donald Shoup

In 2011, San Francisco adopted the biggest price reform for on-street parking since the invention of the parking meter in 1935. Most cities’ parking meters charge the same price all day, and some cities charge the same price everywhere. San Francisco’s meters, however, now vary the price of curb parking by location and time of day. Download the PDF.
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Two-Way Street Networks: More Efficient than Previously Thought?

Vikash V. Gayah

One-way streets in downtown areas are receiving a critical look. City officials and urban planners have started a movement to convert downtown street networks from their traditional one-way operation to two-way operation. This effort seems to be largely successful—many cities (e.g., Denver, CO; Dallas and Lubbock, TX; Tampa, FL; Des Moines, IA; Salina, KS; Kansas City, MO; Sacramento, CA) have either recently made or are in the process of making such conversions. These conversions are intended to improve vehicular access and reduce driver confusion. Many additional factors go into this decision, but the general premise is clear: travelers and residents prefer two-way streets for a variety of economic and livability reasons, while traffic engineers and transportation planners believe that one-way streets serve traffic more efficiently. Download the PDF.
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Political and Public Acceptability of Congestion Pricing: Ideology and Self-Interest in Sweden

Björn Hårsman and John Quigley

Thirty-five years ago, economist John Kain proposed several simple pricing mechanisms for roadways that would "improve urban transportation at practically no cost." At about the same time, Nobel laureate William Vickrey championed a number of likeminded ideas, especially in New York City, that would reduce traffic congestion and improve the efficiency of the transport sector. Some of these proposals would also involve "practically no cost," even using the technology of the 1960s. For example, Vickrey proposed varying the tolls on New York's George Washington Bridge with the time of day, which would make rush-hour driving more expensive and reduce traffic congestion.

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Megacities and Megatraffic

Mark Kutzbach

Scan the newspaper in any big city of a rapidly developing country and you will probably see complaints about traffic congestion. Traffic congestion in developing megacities not only aggravates commuters but also isolates them with time-consuming, unreliable, and expensive commutes. In Mumbai, India, for example, The Mumbai Mirror reported in early 2010 that India's champion athletes missed the closing ceremony of the South Asian Games due to the city's "never-ending traffic jam."

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  • Traffic 1

Traffic Congestion and Greenhouse Gases

Matthew Barth and Kanok Boriboonsomsin

Surface transportation in the United States is a large source of greenhouse gas emissions, and therefore a large contributor to global climate change. Roughly a third of America’s carbon dioxide (CO2) emissions come from moving people or goods, and 80 percent of these emissions are from cars and trucks. To reduce CO2 emissions from the transportation sector, policy makers are primarily pushing for more efficient vehicles, alternative fuels, and reducing vehicle miles traveled (VMT). Those who promote vehicle improvements have focused on building lighter and smaller vehicles (while maintaining safety), improving powertrain efficiency, and introducing alternative technologies such as hybrid and fuel cell vehicles. Alternative fuel possibilities include many low-carbon options such as biofuels and synthetic fuels.

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Categories: ACCESS 35, Fall 2009|Tags: , |
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Moving Los Angeles

Paul Sorensen

People often complain about traffic in Los Angeles, and with good reason. The Texas Transportation Institute publishes annual traffic statistics for metropolitan areas across the United States, and the greater Los Angeles region routinely tops the list for such measures as total congestion delays and congestion delays per peak-period traveler. Against this backdrop, RAND was recently asked to evaluate and recommend near-term strategies that could meaningfully reduce LA’s traffic within a period of five years or less. Note that this timeframe precludes land use policies, which take longer to bear fruit, and major infrastructure investments. In addressing this question, we found it helpful (a) to review general insights from the transportation literature on the causes and potential cures for traffic congestion, and (b) to diagnose the specific local conditions that contribute to the notoriously severe congestion in Los Angeles.

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