ACCESS 48, Spring 2016

Going the Extra Mile: Intelligent Energy Management of Plug-In Hybrid Electric Vehicles

Kanok Boriboonsomsin, Guoyuan Wu, and Matthew Barth

Plug-in hybrid electric vehicles (PHEVs) have generated significant interest for their potential to decrease dependence on imported oil and to cut pollution and greenhouse gas emissions. While hybrid electric vehicles (HEVs) rely on their internal combustion engines to recharge their batteries, PHEVs generally have larger batteries and can be recharged by plugging into an outside electricity source, such as a standard home outlet (Figure 1). As a result, PHEVs are potentially more efficient and cleaner than HEVs, in part because more of their energy can come from clean, renewable sources.

Download the PDF.

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.

Download the PDF.

A Driving Factor in Moving to Opportunity

Evelyn Blumenberg and Gregory Pierce

In 1992, the US Congress authorized the Moving to Opportunity (MTO) housing voucher program to operate in five large metropolitan areas: Baltimore, Boston, Chicago, Los Angeles, and New York. The MTO program represented a radical departure from standard housing assistance programs, which clustered participants in very poor neighborhoods that offered few opportunities. Running counter to previous policy, MTO used an experimental framework to assess how moving households on assistance to low-poverty neighborhoods can affect their employment, education, and household income. Under the program, residents were randomly assigned into three groups. The first group received housing vouchers that could be used only in neighborhoods with poverty rates under 10 percent. The second group received similar housing vouchers but with no neighborhood restrictions. The third group did not receive vouchers but remained eligible for public housing and other social programs.

Download the PDF.

Investing in Transportation and Preserving Fragile Environments

Martin Wachs and Jaimee Lederman

In the early 1970s, the California Department of Transportation (Caltrans) owned large tracts of environmentally sensitive land near Beach Lake in the Sacramento River Valley. The land, acquired in anticipation of future projects but deemed no longer necessary, was to be declared surplus property and sold according to department protocol. One enterprising staff member, however, was thinking differently. He urged Caltrans to hold on to the land and use it for environmental mitigation credit to offset damage from future transportation projects in other areas. In an unusual move, the agency adopted his creative proposal, and the experiment paid off handsomely. In the following decades, the land fulfilled mitigation requirements for 49 separate projects in 14 counties with documented cost savings to Caltrans of over $25 million.

Download the PDF.

Cutting the Cost of Parking Requirements

Donald Shoup

At the dawn of the automobile age, suppose Henry Ford and John D. Rockefeller had hired you to devise policies to increase the demand for cars and gasoline. What planning regulations would make a car the obvious choice for most travel? First, segregate land uses (housing here, jobs there, shopping somewhere else) to increase travel demand. Second, limit density at every site to spread the city, further increasing travel demand. Third, require ample off-street parking everywhere, making cars the default way to travel.

Download the PDF.

THE ACCESS ALMANAC: Running to Work

Robert Cervero

As a transportation researcher, I sometimes get asked what falls into the Census’s “other” category of how people get to work—hoverboarding, rollerblading, kayaking? In Ottawa, three percent of commuters ice-skate to work in winter months. In other cities, notably big, dense ones with awful traffic and jam-packed subways, an increasingly popular way to commute is running. Lacing up running shoes and hoofing it to work is arguably the most active form of active transport and helps meet the Surgeon General’s recommended 30 or more minutes of physical activity per day. Combining two things we need to do—exercising and getting to work—can pay off. Research shows active commuters cut their odds of obesity by 50 percent.

Download the PDF.