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InTransition Magazine : Transportation Planning, Practice & Progress

Archive Edition

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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.

Train Stations Attracted Startups in Two Cities

A Mineta National Transit Research Consortium report concluded that rail stations were a magnet for new businesses in the Portland and Dallas metro areas over a two decade period. The cities were selected for comparison because of their relatively new light rail systems. A time-series database of firm births spanning 1991-2008 provided the data used for the analysis.


Dallas Area Rapid Transit

The results showed that newly formed businesses tended to cluster in higher numbers around stations in Portland than Dallas. The authors posit that this may be due to local policies, or to the “higher value of rail accessibility in the Portland context.” They noted that, in contrast to Dallas, Portland has both an urban growth boundary (which seeks to centralize development in the core of the metropolitan area), and parking caps in their Central Business District, which have both likely contributed to a more accessible transit network.

Despite the weaker association between transit stations and new firms in Dallas, the results demonstrated that in both regions, firms with more than five workers were more likely to launch near rail stations, and that positive relationships between firm births and rail station proximity were found across all industries. The authors add that more research is necessary to explore the policy implications of these findings, as improving rail transit is often looked to as a method of spurring a region’s economic growth.

The study, “Transit Access and the Agglomeration of New Firms: A Case Study of Portland and Dallas,” is available as a free report at transweb.sjsu.edu.

—Researchers: Robert B. Noland, Daniel G. Chatman and Nicholas J. Klein, Mineta National Transit Research Consortium.

 Distracted Driving Prevalent Among Parents with Kids in Car

Parents with children in the car are no less likely to engage in driving distractions like cell phone use than drivers from the general population, according to a study by the University of Michigan.

The study was based on responses of 570 parents of 1- to 12-year-old children who arrived in the emergency departments of the two hospitals. Ninety percent of parent drivers surveyed said they engaged in at least one of the 10 distractions examined in the study while their child was a passenger and the vehicle was moving. Roughly two-thirds of respondents said they’ve talked on cell phones and one-third said they’ve texted while driving their child, consistent with other studies in the general population. Drivers admitted to additional distractions, such as giving food to their child more frequently than they disclosed talking on a cellular phone.

The researchers also found that those parents with higher education and who were non-Hispanic whites were more likely to admit cell phone and directions-related distractions like use of navigation systems.

“If this finding is a result of greater access to technology among more highly educated and non-Hispanic white parents, we can expect the problem of technology-based distractions to expand because national rates of cell phone ownership in the U.S. have climbed above 90 percent,” said lead author Michelle L. Macy, an emergency medicine physician at the University of Michigan’s C.S. Mott Children’s Hospital.

Whether a driver engaged in a distraction also was significantly associated with the age of the child. Odds of reporting a child-related distraction was higher among parents of children between the ages of 2 and 8 than among parents of 1-year-olds.

The study, “Potential Distractions and Unsafe Driving Behaviors Among Drivers of 1- to 12-Year-Old Children,” was published in the May-June 2014 issue of the journal Academic Pediatrics.

—Researchers: Michelle L. Macy, Rebecca M. Cunningham, Patrick M. Carter, Raymond Bingham and Gary L. reed, University of Michigan.

More Bicyclists on the Road Leads to Fewer Collisions

A study released by the University of Colorado at Denver’s College of Engineering and Applied Science concluded that a higher number of bicyclists in a city leads to fewer bicycle vs. automobile crashes. This finding seems to lend support to earlier “safety in numbers” theories, though the specific reasons behind the decrease in collisions remains unknown.

The researchers focused on Boulder, Colorado, where approximately 12 percent of the population rides bicycles—one of the highest rates in the country. It is therefore one of the few cities in the U.S. that experiences the bicycling safety benefits already documented by studies conducted in Europe, according to study co-author
Wesley Marshall.

To carry out the study, the researchers developed safety performance functions (SPFs) for bicycles, which model the mathematical relationship between the frequency of crashes and major factors related to them. While there are SPFs for vehicles, there are none for bicycles. They created the SPFs by studying crashes at intersections throughout the city where more than two-thirds of bicycle-vehicle collisions occur. This data was then compared to bicycle count data, and the researchers found that the chance of collision decreased with more bicyclists.

The risk of accident was relatively high at intersections with fewer than 200 bicyclists per day. “Anywhere above this threshold is where we are seeing the largest safety benefits,” Marshall said.

Given the rise in bicycling across the U.S., the authors believe these results could have national implications for transportation. “In fact, we are beginning to find that cities with a high level of bicycling are not just safer for cyclists, but for all road users,” he said. “Improving the streets to better accommodate bicycles may enhance safety for everyone.”

The study, “Bicyclist safety performance functions for a U.S. city,” was published in the April 2014 issue of the journal Accident Analysis & Prevention.

—Researchers: Wesley Marshall, Bruce Janson, and Krista Nordback, University of Colorado at Denver,
College of Engineering and Applied Science.

Increase Seen in Mobile Devices Use by Intercity Bus Riders

A study by DePaul University’s Chaddick Institute for Metropolitan Development reveals the use of personal electronic devices on intercity bus trips continues to rise sharply.

“As opposed to airline customers who cannot surf the Internet, email, text or place phone calls during takeoff or landing, which can consume more than 40 minutes of flight time, customers traveling by an express bus service like megabus.com are able to use their devices from the moment the bus arrives to the time they depart at their destination,” said Joseph Schwieterman, director of the Chaddick Institute and co-author of the study.

The study collected data from 7,034 passengers on 106 bus, train and plane departures during February-June 2014 and made comparisons with a similar sample from 2013. The study found that the use of personal devices among passengers remains on an upward trajectory, noting the following:

• Express, city-to-city buses services —many of which use Wi-Fi access as a selling point—experienced the fastest increase in technology use. More than 59 percent of passengers were “powered up” (an increase from 46.4 percent last year), a rate that outdistances Amtrak, conventional bus and air travel by a wide margin.

• Nearly 90 percent of passengers use electronic devices at some point during their trips.

• Technology use on airlines remained virtually flat and continues to lag behind other modes, suggesting that the relaxation of the FAA policy on the use of personal electronic devices is having little effect. The new policy allows the use of certain devices during takeoffs and landings but appears to have been greeted unenthusiastically by flyers who are still unable to connect to Wi-Fi or 3G/4G systems, send text messages or place phone calls.

The DePaul University study, entitled “The Personal Tech Tidal Wave: The Rising Use of Electronic Devices on Intercity Buses, Planes, & Trains” is available at www.depaul.edu.

—Researchers: Joseph P. Schwieterman, Marisa Schulz, Justin Kohls and Noah Boggess, Chaddick Institute for Metropolitan Development.

Census Data Shows Transportation Jobs, Sales on the Rise

Data released in June by the U.S. Census Bureau pointed to the growing strength of private sector transportation businesses as job creators, even throughout the worst of the recession.


According to the 2012 Economic Census statistics, the number of people employed by shuttle services, vanpools and similar businesses demonstrated a sharp increase from 2007 through 2012, from 11,696 jobs in 2007 to 17,719 in 2012—a 51 percent jump. A similar trend was shown in total sales, with these businesses posting a 51 percent increase from approximately $760 million in 2007 to $1.1 billion in 2012.

Among other highlights from the data:

• The taxi service industry demonstrated one of the highest increases in payroll per employee within the transit and ground passenger transportation industry—an increase of almost 17 percent.

• Private local, fixed-route passenger transportation by road and rail generated sales of $13.3 billion in 2012.

• Total employment from school and employee bus transportation businesses increased by 25,589 (or nearly 13 percent) since 2007. Payroll per employee, however, decreased by about 4 percent over the same period.

The Economic Census is conducted every five years and provides a comprehensive and detailed profile of the U.S. economy. The statistics above account only for privately held and publicly traded firms in the industry; information on government-owned transit and ground passenger transportation can be found in the Census of Governments. Reference information about the 2012 Economic Census is available at www.census.gov/econ/census.

—Researcher: United States Census Bureau.

Road Death Reductions Levelling Off Worldwide

While the number of road fatalities fell by 1.7 percent last year in the 31 countries covered by the International Road Traffic and Accident Database (IRTAD), this was the lowest average reduction rate recorded in 10 years.

Road safety policies in IRTAD countries are considered an overall success—between 2000 and 2012, the annual death toll has fallen by nearly 40 percent, a difference of 45,000 fewer deaths per year. However, given new data published in the International Transport Forum’s Road Safety Annual Report in May, the organization concluded that the levelling of the road death rate will be insufficient to contribute substantially to the United Nations target of halving road fatalities by 2030.

An estimated 1.3 million people die on the world’s roads each year, mostly in emerging economies, and this number is forecast to rise to 2 million by 2020 if strong action is not taken, according to the report. Additionally, the authors note that the societal costs of road crashes are important to consider: estimations of crash costs range from 1-3 percent of GDP, and could grow as estimation methods are refined.

Despite the levelling of the death-reduction rate, individual countries have demonstrated remarkable progress. In 2012, five European countries achieved a historic first by reducing their annual road fatalities to three or fewer per 100,000 people. Provisional data for 2013 indicates that at least 22 countries were able to reduce their road fatalities, nine of those by more than 10 percent. Moving forward, IRTAD is encouraging governments to gather police and hospital data to analyze and hopefully reduce the rate of serious injury due to cycle crashes.

The report, “Road Safety Annual Report 2014,” was published in May 2014, and is available at www.internationaltransportforum.org/irtadpublic.

—Researchers: International Transport Forum at the Organisation for Economic Co-operation and Development, Paris.

Study: No Safety Difference between Electronic, Static Billboards

A study released by the Federal Highway Administration in December concludes that drivers are no more likely to be distracted by digital billboards than they are by standard billboards.

While there are currently regulations for luminance and how fast the images can change on commercial electronic variable message signs (CEVMS), the report noted that the FHWA felt it was necessary to reevaluate their safety given the proliferation of LED and LCD billboards in recent years.

The study asked participants in Reading, Pennsylvania, and Richmond, Virginia, to drive along fixed routes while equipment in the car tracked their eye movements, assessing the direction and duration of glances between the roadway and surrounding environment. Driving routes were chosen based on the presence of CEVMS and standard billboards, and glances were evaluated particularly with relation to billboards within the driver’s field of vision. Previous research has shown that glances away from the roadway exceeding two seconds carry increased crash risk, but the study’s results were all well below this accepted threshold.

“The drivers in this study devoted between 73 and 85 percent of their visual attention to the road ahead for both CEVMS and standard billboards,” the researchers said, concluding that “the presence of CEVMS did not appear to be related to a decrease in looking toward the road ahead.”

Although these results add to the growing body of knowledge on the topic, the authors noted that the study “does not present definitive answers to the research questions investigated.” They discussed various limitations, including an inability to accurately track glances toward objects farther than 1,000 feet away, the potential modification of driver behavior due to the presence of researchers and eye-tracking equipment within the car, and the potential for sampling bias.

The study, “Driver Visual Behavior in the Presence of Commercial Electronic Variable Message Signs (CEVMS),” is available online at www.fhwa.dot.gov.

—Researchers: William A. Perez, Mary Anne Bertola, Jason F. Kennedy and John A. Molino, Federal Highway Administration.

Transportation Vouchers Improve Quality of Life for Disabled

A study focusing on a Michigan transportation voucher program for persons with disabilities found that about 70 percent of participants experienced an improvement in emotional well-being and community involvement because of their enrollment in the program. Before the program was instituted, 61.6 percent of respondents felt that they had missed out on work-related opportunities or social events due to problems with transportation.

While public transportation can sometimes meet the needs of the disabled, the authors note that it has several limitations, including finite hours of operation, cost, accessibility and gaps in service areas. Over half of the respondents indicated that their transportation options were limited because of where they lived, and 38 percent reported that they relied upon family and friends for transport instead of public transit, walking or biking. Additionally, the researchers found those with physical disabilities encountered fewer barriers to transportation in comparison to those with intellectual disabilities or mental illness.

The authors assert that voucher programs, given their flexible nature —funds directly “follow” individual passengers based on miles traveled, regardless of the type of transport —can be more efficient and cost-effective than public transportation.

The study concludes that these programs could be particularly important to implement in the future, given that recent statistics indicate there are 3.5 million Americans unable to leave their homes due to transportation challenges, 1.9 million of whom have disabilities. So far, voucher programs similar to the Michigan demonstration have been introduced in 12 states, primarily in rural counties where access to public transit is limited.

The study, “Benefits and Quality of Life Outcomes from Transportation Voucher Use by Adults with Disabilities,” was published in the December issue of the Journal of Policy and Practice in Intellectual Disabilities.

—Researchers: Preethy S. Samuel, Krim K. Lacey, Wayne State University, Detroit; Chesley Giertz, Karen L. Hobden, the Arc of Northwest Wayne County, Redford, Michigan; and Barbara W. LeRoy, University of Windsor, Ontario, Canada.

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