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InTransition Magazine : Transportation Planning, Practice & Progress

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Research Exchange

About Research Exchange

  • Research Exchange gathers brief summaries of ongoing or recently completed research about critical topics in transportation. We invite readers to suggest studies that merit inclusion.

Making Congestion Pricing Fair for the Disadvantaged

Congestion pricing programs can be implemented fairly and effectively when transportation planners incorporate equity goals into the early planning stages, according to a study by the RAND Corporation.

Policymakers adopt congestion pricing—the practice of charging drivers more to travel particular routes at peak travel times—to reduce gridlock and air pollution, and to raise revenues for transportation projects. However, since these policies impose a cost on driving in a location that previously was free, critics often suggest that they will disproportionately impact lower-income drivers, so some would be “priced off” the roads.

The authors contend such inequities can be offset. The study said policymakers developing a congestion pricing proposal should test it through modeling to determine whether low-income or other transportation-disadvantaged groups are disproportionately affected; conduct outreach so that residents understand the proposal and have opportunities to offer suggestions; and monitor the system after it’s enacted, changing it periodically if it’s not meeting initial goals for fairness.

Methods recommended to achieve equitable outcomes include spending the revenues on transportation projects that benefit the whole public; offering discounts and exemptions that benefit low-income and disabled drivers; and other tools that offer relief to those unfairly impacted, such as a residential parking permit program that prevents visitors from parking in communities just outside the program’s boundaries to avoid the fees.

The study, “Equity and Congestion Pricing: A Review of the Evidence,” was sponsored by the Environmental Defense Fund (EDF). It can be viewed in its entirety at

—Researchers: Liisa Ecola and Thomas Light, RAND Corporation.

Study: Switchable-Battery Electric Cars the Future in U.S.

For this product, the “batteries not included” version may be the better deal. A study released in July by the University of California, Berkeley, concluded that the mass adoption of electric vehicles in the U.S. can be accelerated by outfitting them with replaceable batteries.

According to the university, this is the first study to forecast the adoption rates of electric vehicles that run on pay-per-mile service contracts, which operate similar to cell phone minute plans. Under this system, drivers could pull into service stations to have their batteries replaced in a timeframe comparable to that of getting a car refueled. The fresh battery would be provided by a company as part of a service plan.

The study noted that in order to gain widespread acceptance, electric cars must be able to compete with regular autos in terms of price, the range they can travel and reliability. Not having to pay the high cost for a battery upfront would make the purchase price of an electric car competitive with a gasoline-powered car. With a network of battery stations in place, electric vehicles could have a far longer driving range. And by placing ownership of the battery in the hands of a private operator, consumer concerns over the lifetime or durability of the battery would be eliminated, according to the study.

The study predicts that electric vehicles with pay-per-mile pricing will account for 64 percent of light vehicle sales and comprise 24 percent of the U.S. light-vehicle fleet by 2030. It also foresees a net gain of up to 350,000 new jobs by 2030 through electric vehicle adoption, a 62 percent reduction in emissions from 2005 levels, savings of up to $205 billion on healthcare costs associated with emissions from combustion engine vehicles, and a decline in oil imports of up to 3.7 million barrels per day.

The study, “Electric Cars in the United States: A New Model with Forecasts to 2030,” can be viewed online at

—Researchers: Thomas Becker, Ikhlaq Sidhu and Burghardt Tenderich, University of California, Berkeley, Center for Entrepreneurship & Technology.

‘60 Is the New 40’ with ATV Fatalities

With all-terrain vehicle (ATV) deaths among seniors rising sharply, rider education and safety efforts should no longer be just targeted toward youths, a recent study concluded.

Victims 60 and older accounted for 8 percent of ATV hospitalizations from 2000-04, with the total number rising 19 percent each of those years. However, the crash statistics were particularly high in the study’s chief area of focus, the state of West Virginia.

The researchers reviewed and compared state ATV fatality records between the years of 1985-1998 and 1999-2007. They found that from the first to the second period, deaths among those 65 and older rose 150 percent, from 11 to 28. Both numbers placed West Virginia well above the national average in deaths per 100,000 residents. The fatality trend among older riders was predominantly male, as only one female death, an 87-year-old in 2005, was recorded in either period. Over 60 percent of the deaths involved the vehicle overturns and rollovers.

Why West Virginia? The authors speculated on a handful of reasons. Because of the Mountain State’s terrain, ATVs have grown in popularity among farmers and land owners as an alternative to trucks and tractors. Second, West Virginia’s residents are slightly older than the national average, with 15 percent over 65 vs. a 12 percent U.S. average. The authors also believe there’s an important national trend at work—healthier and more active than ever before, seniors are continuing activities in their retirement years that they used to quit in their 40s and 50s.

“[T]he data presented in this study may be highlighting the beginning of a shift in recreational injuries among older adults—perhaps reflecting the common catchphrase that ‘60 is the new 40,’” the authors note. To compensate for this, the study suggests that safety courses should be designed for senior ATV riders, with topics ranging from the importance of helmet use to proper navigation techniques on sloped terrain.

 “ATV Deaths Among Older Adults in West Virginia: Evidence Suggesting that ‘60 is the New 40!’” appeared in the May 2009 Southern Medical Journal.

—Researchers: James C. Helmkamp and Mary W. Carter, West Virginia University.

Rural Transit Agencies Can Save By Pooling Resources

Small, rural transit providers could save money and improve their service by sharing regional maintenance centers (RMC), according to a group of researchers in Texas.

Rural transit systems typically handle their maintenance needs in-house or through private contractors, and both routes have their drawbacks, the authors said. Handling the work in-house can be expensive for these small services since it requires them to employ specialists and maintain extensive parts inventories.

Using contractors—such as state-approved vendors, local garages and auto dealerships—sometimes exposes rural transit providers to shoddy service, inflated costs or long repair times, especially when uncommon equipment is involved. This can lead to service disruptions if the contractor doesn’t have a comparable vehicle to provide as a loaner.

The study discussed a RMC program in Illinois as a model other states might follow. The Illinois Department of Transportation runs three RMCs which served 64 agencies as of 2006. The RMCs’ main purpose, according to the study, was not to compete with local businesses, but to provide non-routine maintenance work. The facilities were strategically located at sites within a 60-mile radius of most of the agencies they served. The RMCs grouped rural systems with larger urban transit operators that could share their mechanics, who had more experience repairing public transportation vehicles.

The study concludes that a RMC system like Illinois’ can prove very beneficial, as long as they’re not set up with a “one-size-fits-all approach” Factors like location, the specific types of vehicles they’ll serve, fleet age and staffing needs must all be considered to ensure the agencies get the most for their money. The facilities could also serve as central locations for training rural transit operators and their personnel.

The study, “The Concept of a Regional Maintenance Center,” appeared in the Journal of Public Transportation, Vol. 12, No. 3, 2009.

—Researchers: Mario G. Beruvides, James L. Simonton, Natalie M. Waters, Ean Ng, Siva Chaivichitmalakul, Cheng-Chu Chiu-Wei, Pelin Z. Altintas and Phil Nash, Texas Tech University; Luis Barroso, Instituto Tecnologico de Monterrey-San Luis Potosi; Paul Moon, Texas Department of Transportation.

Incentives Could Encourage Privatization of Port Security

An incentive system for shippers could help push some of the costs and responsibilities of port security from the federal government to the private sector, according to a study published in February.

More than 15 million containers enter the United States through its ports each year carrying more than $400 billion in products. The researchers investigated how the U.S. Bureau of Customs and Border Protection (CBP) should structure its inspection programs to improve safety against terrorist threats while maintaining fluidity at its borders.

Because inspection-driven congestion is costly, CBP provides incentives for firms to improve security upstream in the supply chain to reduce the inspection burden at U.S. ports. The researchers evaluated the CBP Customs-Trade Partnership Against Terrorism (C-TPAT) incentive program to understand its effect on the CBP, firms and terrorists. They contend that, with proper incentives, C-TPAT can shift some of CBP’s security burden to private industry while simultaneously reducing total terror prevention costs.

From the perspective of the companies, the benefits of joining C-TPAT must offset the additional investment required to comply with the security guidelines, according to the study. The authors focus attention on the benefits related to reducing the frequency of inspections.

An additional level of benefits would be realized from a proposed tiered membership of C-TPAT, with the highest-performing members of C-TPAT being eligible for access to an inspection-free shipping process—referred to as the “green lane” concept. The authors note that implementing this proposal is contingent on research advances and the successful rollout of “smart” containers.

Securing the Containerized Supply Chain: Analysis of Government Incentives for Private Investment” appeared in the February 2010 issue of Management Science, a journal published by the Institute for Operations Research and the Management Sciences.

—Researchers: Nitin Bakshi, the London Business School, Noah Gans, the Wharton School of the University of Pennsylvania.

Are Teen Girl Drivers More Dangerous than Boys?

Teenage girls may now be riskier and more aggressive behind the wheel than the boys in their class, according to a study commissioned by the AllState Foundation.

An online survey of 1,063 teens nationwide posed a series of questions relating to their attitudes and behaviors while driving. Nearly half of the female respondents claimed they’re likely to drive 10 mph over the speed limit vs. just over one-third of the boys.

According to the survey, girls are also more apt to drive distracted. Fifty-one percent of girls said they were likely to use a cell phone to talk, text or email while driving, as opposed to 38 percent of boys. Eighty-four percent of girls reported they were likely to change the music or adjust the volume while driving, while 69 percent of boys said the same.

In addition, only 53 percent of female passengers said they speak up if they’re scared or uncomfortable with the driver, vs. 66 percent of the boys. Both genders claimed fear of social rejection and being ignored as the most common reasons why they wouldn’t speak their minds.

The study concluded that texting has rapidly become the biggest distraction for all teen drivers. About half of the respondents cited texting as a distraction, while less than one-third said the same in 2005. On a related note, 82 percent of all the respondents reported they use cell phones while driving.

The study, “Shifting Teen Attitudes: The State of Teen Driving 2009,” is a follow-up to a similar project called “Chronic: A State of Teen Driving in 2005.” Both can be found on AllState’s website,

—Researchers: TRU Research, Chicago.

Few Agencies Target Women’s Fears of Transit Environments

A report published by the Mineta Transportation Institute in November analyzed the reasons women fear for their safety in public transit settings and suggested some actions operators might take to mitigate those concerns.

Dan Burden,

The study included a thorough literature review on women’s safety on transit, interviews with representatives of national interest groups, a survey of 131 U.S. transit operators, and case studies and best practices from the U.S. and abroad. The survey of transit operators found that only a handful of agencies in the U.S. currently have programs that target the safety and security needs of women riders.

“Most survey respondents believed that women have distinct safety and security needs, but only one-third of them believed that transit agencies should implement specific programs to address these needs,” said Anastasia Loukaitou-Sideris, the principal researcher.

According to the report, research has shown that women feel unsafe in many public spaces, including transportation environments such as desolate bus stops and train cars, dimly lit park-and-ride lots and parking structures. Overcrowded transit vehicles also stress many women, who often avoid them by changing their transportation modes and travel patterns.

The women who were interviewed offered design, policing, security technology, education and outreach strategies that would make female riders feel safer in public settings. Based on lessons from initiatives already used outside the U.S., as well as from the women’s interviews, the study includes a list of recommendations, such as including women’s opinions in transit planning, collaboration between transit agencies and nonprofit groups, prioritizing safety and security needs in the transportation system, and other points.

The full study, “How to Ease Women’s Fear of Transportation Environments: Case Studies and Best Practices,” can be viewed online at

—Researchers: Anastasia Loukaitou-Sideris, Amanda Bornstein, Camille Fink and Linda Samuels, UCLA Department of Urban Planning; Shahin Gerami, San José State University.

Tax on Milage Rather Than Gasoline Would Be Equitable

Proposals for a tax on miles driven as an alternative to gas taxes are not likely to disproportionately harm low-income travelers or other vulnerable segments of society. However, policymakers may have to consider structuring the taxes to preserve incentives for fuel-efficient vehicle purchases.

Those are among the conclusions of a recent study examining how a mileage tax would work and its financial impacts on residents. A mileage tax, also knows as a vehicle miles traveled (VMT) tax, has been proposed as a solution to what the authors called a crisis facing the current system of highway finance in the U.S. The authors note that the federal fuel tax has not changed since 1993 although it has experienced a 33 percent reduction in real purchasing power since that time. Compounding the problem is the increasing fuel efficiency of vehicles, which diminishes the revenue raised through the gas tax.

Drawing on 2001 household travel data, the study modeled the effect of a tax of 1.2 cents per mile compared to the current Oregon fuel tax of 24 cents per gallon.

The VMT tax was found to be regressive, placing a greater burden on low-income residents than the already regressive gas tax. Yet the impact was very small, especially when compared to the regressive impact of rising fuel prices, which jumped from $1.46 per gallon in 2001 to $2.64 by 2008. Despite the concern that rural residents, who drive longer distances, would be harmed, they actually benefited under a VMT tax because they would no longer be penalized for driving less fuel-efficient vehicles.

Yet removing this penalty could undermine the market for fuel efficiency, including hybrid cars. Among possible fixes suggested by the authors was leaving the gas tax in place for cars getting under 20 miles per gallon, or a mileage fee that increases in steps proportional to the lower a car’s fuel economy.

The full study “Distributional impacts of changing from a gasoline tax to a vehicle-mile tax for light vehicles: A case study of Oregon,” was published online in May by the journal Transport Policy.

—Researchers: B. Starr McMullen and Kyle Nakahara, Oregon State University; Lei Zhang, University of Maryland.

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