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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.

iPods and Eye Movement

Operating an iPod draws drivers’ eyes off the road and leaves them less prepared to handle sudden traffic incidents, according to evidence collected by a team of Canadian researchers. With their lists of song titles, artists, functions and menu options, MP3 players generally, and iPods specifically, are more complex to operate than CD players and other common car audio devices. The frequency of glances needed to operate iPods means more time drivers spend with their eyes inside the car and a greater potential for crash risk, the study’s authors noted.

Nineteen drivers ages 18 to 22 participated in a seven-session study held in the University of Calgary Driving Simulator. Participants wore headgear that recorded their eye movements during regular driving conditions and while operating iPods mounted on the car’s center column. Sudden events like pedestrian crossings, cars ahead hitting the brakes, abrupt vehicle pullouts and late yellow lights occurred at random, and the drivers’ reaction times and success in handling the situations were measured. Each event was designed to be a surprise that would result in a collision without a quick reaction.

Two difficulty levels of iPod interactions were performed. Easy iPod tasks included turning the music players on or off, pausing a song or skipping ahead a few tracks. Difficult tasks involved locating specific tunes from a list of over 900 stored in the memory.

Throughout the sessions, 115 crashes were recorded, and the iPods may have played a role in the majority them. According to the study, almost half of those accidents, 53, occurred while the drivers were performing difficult iPod tasks, 34 during easy tasks and 28 occurred during normal driving conditions. The drivers did improve their abilities to handle iPods while driving with practice, but the report said their driving performance while doing difficult tasks never approached their ability during normal, undistracted conditions.

—Researchers: Susan Chisholm, Jeff Kaird, Julie Lockhart, Lisa Fern, Elise Teteris, University of Calgary.

Planners: Less Parking Spaces a Good Rx for Medical Offices

Municipal codes often demand more parking for medical office buildings (MOBs) than needed, two planners concluded in a report published in August’s ITE Journal. After conducting research on 50 MOBs in eight states, the authors recommended that buildings have 4.5 spaces for every 1,000 gross square feet of floor area. Most local ordinances base MOB parking requirements on square footage rather than the number of employees, doctors, patients or visitors, the authors noted. The 4.5 standard would provide enough of a cushion for user convenience and would generally suffice to handle the temporary loss of spaces caused by snow removal, maintenance, construction and other out of the ordinary events, they reported.

Researchers observed the MOBs on Mondays and Wednesdays from March through August, during what was considered typical activity levels. Suburban locations were chosen to avoid the influence of adjacent land uses or mass transit more typical of urban environments. Parking counts were taken at 11 a.m. (the peak hour for MOB use) and then compared to building size. The average site surveyed was 64,427 square feet.

The mean peak hour parking accumulation rate was found to be 3.23 spaces per 1,000 square feet, well less than what zoning demands at many of the sites. In fact, 60 percent of the MOBs were in areas that required more than the 4.5 spaces recommended by the study. The most common code requirement for the areas studied was five spaces per 1,000 square feet, with 19 buildings, or 38 percent, having to adhere to that standard.

—Researchers: John Dorsett and Mark Lukasick, Walker Parking Consultants.

NJIT Finds Context Sensitive Highway Project Met Needs

Projects to widen or extend highways are a common use of federal transportation funding, sometimes costing hundreds of millions of dollars each. But what do such projects actually accomplish? How do they impact surrounding neighborhoods? Surprisingly, these are questions rarely asked—or answered.

Researchers at the New Jersey Institute of Technology (NJIT) took on this challenge in a five-year study of the completion of the 1.8-mile Route 21 “missing link” through the City of Passaic, N.J. It allows cars to reach Route 46 to the north without threading through local streets. Their findings, now in draft form, will be released in the next few months.

The Route 21 project, completed in 2000, was undertaken through a context sensitive design process that took into account community needs and context. For instance, portions of the bridges, retaining walls and noise barriers were faced in brick to blend into the urban surroundings and, based on local input, only a partial interchange was created with Route 46 to limit taking homes through eminent domain.

The evaluation of the project’s impact, which commenced in 2002, focused on economic and quality of life issues. This included assessing impacts on neighborhoods, residential and commercial real estate values, the success of commercial enterprises, and traffic and safety. It also assessed aesthetics and viewscape, traffic flow, noise impacts and other factors of concern to the local population. Evaluation methods included a series of surveys of residents and businesses, traffic counts and analysis of economic and other data.

For the most part, according to the study’s draft report, the predictions about the project’s impacts contained in the Environmental Impact Statement have been borne out in the years following the project completion. This includes a reduction of traffic on local streets, traffic noise at acceptable levels, real estate values that increased or held steady and general (though not universal) acceptance of the project. The draft report recommends that a one- or two-year “post assessment review,” as performed for the Route 21 project, be considered by the state Department of Transportation for all projects.

—Researchers: Robert Dresnack and Eugene Golub, New Jersey Institute of Technology

Less Stress on the Express

Recent research suggests commuters who ride the rails to work are less stressed by the experience than those who drive. According to “Leave the Driving to Them: Comparing Stress of Car and Train Commuters,” motorists reported significantly higher levels of stress, more negative moods and indicated their trip took more effort and was far less predictable compared to rail riders.

A sample of 122 drivers and 164 NJ Transit train riders commuting from Northern New Jersey to New York City were studied. Researchers used flyers on parked cars, radio and newspaper ads and an advertisement on the E-ZPass Web site to recruit the group and offered incentives that lowered their commuting costs for participation (a monthly ticket for train riders and $100 cash for drivers). All of those chosen were from the same geographic area and had an average commute of 75 minutes, as opposed to the national average of about 25 minutes. To qualify, commuters had to make the same trip at least four days per week, have been commuting on the same route for at least one year and be expected to continue that commute for another year.

Participants filled out standardized surveys asking them to rate their commutes on such factors as the stress induced, the effort required, unpredictability and the mood generated by the experience. A second part of the study found that riders who must transfer to connecting trains experience more stress than those who ride directly to their destination.

The researchers reasoned that the study’s results could be a “marketing bonanza” for transit providers. “Being able to advertise not only that transit provides mobility, but also can provide a benefit to one’s mood and health can be used as a motivational tool to attract new riders,” the report said.

—Researchers: Richard Wener, Polytechnic University, Brooklyn; Gary Evans, Cornell University, Ithaca, N.Y.; Jerome Lutin of New Jersey Transit, Newark.

Study: Nighttime Not the Right Time for Road Work

Despite commonly held assumptions, nighttime road construction could be up to five times more hazardous for workers, according to a recent study. A trio of researchers reported their findings after examining reports related to 121 fatal accidents that took place in Illinois highway work zones from 1996-2001. Because data could not be separated on the basis of nighttime and daytime crashes, researchers pored over raw files and used a computer database to organize the details.

The authors noted that previous studies indicated nighttime construction was being conducted more and more in recent years, in part because it was seen as safer for workers, as they were exposed to fewer cars and cooler temperatures in the summer months. Night construction was also expected to cause less congestion and save on work costs, although previous studies conflict on whether or not worker productivity increases at night.

The actual total of fatal accidents in work zones was well higher during the day than the night. However, the authors contend that the information should be adjusted to consider the much higher volume of traffic passing through work zones by day, the greater number of operational work sites, the longer duration of daylight vs. dark hours and other factors. With a mathematical formula established and applied to the actual crash totals, the researchers determined that if the same number of cars and sites were active at night, the number of fatal accidents would be several times higher than the day. The impacts on weather conditions were also analyzed, but were said to have a limited effect.

In the interest of protecting workers, the study calls for the establishment of a system for reporting and recording accidents in work zones, which would yield more information useful to understanding the safety of daytime vs. nighttime road work.

—Researchers: David Arditi, Illinois Institute of Technology, Chicago; Dong-Eun Lee, Kyungpook National University, South Korea; Gul Polat, Istanbul Technical University, Turkey.

Obedience to New Law a Tough Cell in Portugal

A study of drivers in Portugal found the response to a new law cracking down on hand-held cell phone use to be short-lived. Observations of drivers before, just after and a year following the passage of more punitive legislation in March 2005 indicated that drivers initially cut their cell use by significant numbers, but those rates rebounded to pre-law levels not long after.

Roadside observers with tape recorders collected data on the number of vehicles they saw as well as the gender and ages (estimating above or below 40) of drivers between 3 and 5:30 p.m. on weekdays from January 2005 to April 2006. A total of 66,841 observations were made, all along IC19 near Queluz, a road said to experience some of the most intense traffic in the metro Lisbon region. Phone use was counted only when there was a clear view of the vehicle and phone; on occasions when the observer had difficulty determining what they saw, the vehicles were not counted. All of the data was said to be collected in times of good visibility. All vehicles were counted except motorcycles.

Immediately after the change in law, the cell phone use rate dropped in half, from 1.29 percent of all drivers before to .67 percent after. However, one year later, the results rebounded to 1.27 percent, a number almost identical to that of the days before the legislation. “The reason for this may be the fact that, as time goes by, drivers realize the low risk of being charged and punished for phone use while driving,” the author noted.

The study found that overall, cell phone-using drivers were predominantly young and male. Throughout the four time periods of testing, about 75 percent of those on the phone were men. However, the study noted that this percentage was equivalent to all road users, so a gender trend was not found. Approximately 63 percent of those watched with phones were classified as below 40.

—Researchers: Mario B. Godinho, Technical University of Lisbon, Portugal.

Stats Say Seniors Driving Safer

Although seniors are often stereotyped as bad drivers, a report released by the National Highway Transportation Safety Association in May shows the opposite has been true as of late. From 2001 to 2005, drivers 65 and older consistently had lower rates of fatal accidents than adults 21 to 64.  During that period, the number of drivers 21-64 involved in fatals rose 5.2 percent, while those of their older counterparts dropped 3.6 percent.

This trend has taken place despite the fact that the number of seniors taking to the roads is growing at a faster clip than their juniors. The population of residents 21-64 has increased by 5.4 percent since 2001, while the number of licensed drivers in that age bracket has risen only 5 percent. In contrast, the population of those 65 and older has risen 4.1 percent while the number of licensed drivers in that bracket jumped 6.6 percent in that time span. These opposing trends have led to the proportion of people over 65 with licenses rising from 78 to 80 percent, while that of drivers 21-64 remained close to flat, from 91.7 to 91.4 percent.

The brief report, “Drivers 65 and Older Have Lower Involvement Rates in Fatal Crashes,” includes a state-by-state breakdown of seniors’ involvement in fatal crashes by year. It does not offer any theories regarding the possible causes of these trends.

—Researchers: NHTSA National Center for Statistics and Analysis.

Smart Bike Pilot Helps Supplement Commutes

An automated bike rental system in London appears to have partially accomplished its goals of supplementing public transit, relieving congested bus routes, providing an alternative to carrying bikes on trains and reducing the need for cars at stations. OYBike (On Your Bike) was first launched in the London Borough of Hammersmith & Fulham (LBFH) in August of 2004 and evaluated recently by a pair of local researchers in “Smart Bicycles in an Urban Area: Evaluation of a Pilot Scheme in London.”

OYBike operates through a system of street-based rental stations, which save labor costs by operating electronically. Renters can unlock their bikes using PIN numbers supplied via text messages to their cell phones, and the duration of their rental time is measured by the use of those codes. About 25 stations were operating in 2005, with most set up outside commuter hubs in LBFH, a densely populated residential area that is also home to the BBC headquarters and a few other scattered employment centers. The bikes are bright yellow for safety and equipped with baskets to carry small items.

In September of 2005, a small sample of about 46 users filled out questionnaires about the service in exchange for a usage credit. About 34 percent responded that their OYBike trips were substituting for public transit, and 26 percent said they used rail or Underground service before renting the bikes. While that is relatively small, the authors noted, it does show some potential for the service to be used as a mode away from the station. In addition, about 40 percent of paid trips began or ended at locking posts outside Underground stations, and 13 percent of respondents said they used OYBike to access the Underground. Weather conditions were seen to play a large role in rental numbers.

However, the authors noted they saw OYBike’s greatest potential for growth in the leisure/recreation market. Targeted initiatives aimed at recreational users may be effective, and placing more locking stations at key recreation destinations could provide a way to connect them with public transport stations, they reported. The London Olympics in 2012 was mentioned as one potentially important opportunity for the service.

—Researchers: Robert Noland and Muhammad Ishaque, Imperial College, London.

Buckle Up, Or Your Passengers Won’t

Front-seat passengers are far less likely to use seatbelts when their driver fails to buckle up, a pair of researchers has concluded. An analysis of drivers and passengers in Nevada found that passengers wore seatbelts more than 95 percent of the time when drivers did. That number plummeted to around one-quarter when drivers didn’t buckle up.

Field observers collected data at 50 locations across Nevada between 2003 and 2006. At each site, a minimum of 400 vehicles were observed for seatbelt use by the driver and front-seat passenger. Over 20,000 observations were made each year, with data categorized based on gender and age group of passengers, vehicle type and area type. Sites were chosen where traffic speeds were slow enough to make observations. Vehicles were classified into three types: sedans/station wagons, pickup trucks and vans/SUVs.

Seatbelt use changed in all vehicle types based on driver behavior, but the impact varied. In pickups, passengers whose drivers wore their seatbelts buckled up 89 to 95 percent of the time over the four years measured. Passenger seatbelt use fell to 18 to 23 percent when drivers did not use them.

In sedans/wagons, passenger use was above 91 percent when drivers wore them, and 30 to 38 percent when drivers did not. In vans/SUVs, usage rates topped at least 93 percent each year when drivers wore them and fell to about 30 percent when drivers did not (with the exception of 2006, when about 48 percent of passengers did not wear them).

The study’s authors concluded that based on their findings, media, education and enforcement campaigns focusing on drivers’ seatbelt use could also be effective in raising use by their passengers. They also reason that strategies to increase the use by front-seat passengers would probably impact the drivers.

—Researchers: Vinod Vasudevan, University of Nevada, Las Vegas; Shashi Nambisan, Iowa State University, Ames.

“Children at Play” Signs Called Ineffective

Roadside signs that warn things like “Children at Play” or “Deaf Child at Play” are ineffective and possibly even dangerous, according to a report by the Wisconsin Department of Transportation (WisDOT). In an effort to reevaluate and update its policies regarding such signs, WisDOT staff reviewed the policies of several states, as well as numerous studies compiled by national researchers and government agencies. A September 2007 report titled “Effectiveness of ‘Children at Play’ Warning Signs” contains an overview of WisDOT’s findings.

The sources used came to a unanimous conclusion: There is no evidence these special warning signs reduce driver speeds or crash rates. Possible reasons are that they offer no clear and enforceable guidance to drivers and they lose credibility when they appear too often, according to the report. Furthermore, the signs might actually put children at greater risk because they may encourage the use of those roads as playgrounds, and drivers could infer that there are no children present in areas without such signs. Because of that, local governments could be exposed to legal liability.

Nonetheless, these signs remain widespread as a deterrent to speeders in residential neighborhoods. They are often requested by local homeowners and granted by political leaders to satisfy them, a situation that violates “the principle that signage should be based on engineering, not political, decision making,” the report stated.

“A common theme is the ongoing struggle to explain to members of the public that their requests for these types of signs are based on faulty assumptions about their effectiveness,” according to the report.

Among other potential drawbacks to the “at play” signs: They are costly and a waste of tax dollars; when the novelty of the sign wears off, they no longer attract the attention of the passerby; and unusual warning signs are enticing targets for vandals and souvenir hunters.

The report says that many traffic engineers feel such signs may be appropriate in certain locations, such as sites close to schools for the deaf or blind. It added that despite extensive research, no statistically supported or accident-based studies could be found to back up the apparent consensus of the engineers on this issue.

——Researchers: CTC & Associates, Madison, Wis.; WisDOT Research & Library Unit.

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