While walking or driving, cell phones increase traffic, pedestrian fatalities
September2011

Research shows that talking on the phone while traveling, whether you're driving or on foot, is increasing both pedestrian deaths and those of drivers and passengers, and recommend crackdowns on cell use by both pedestrians and drivers.

Studies, lead-authored by Rutgers University, Newark, Economics Professor Peter D. Loeb, relate the impact of cell phones on accident fatalities to the number of cell phones in use, showing that the current increase in deaths attributed to cell phone use follows a period when cell phones actually helped to reduce pedestrian and traffic fatalities.

However, this reduction in fatalities disappeared once the numbers of phones in use reached a "critical mass" of 100 million, the study found.

These studies looked at cell phone use and motor vehicle accidents from 1975 through 2002, and factored in a number of variables, including vehicle speed, alcohol consumption, seat belt use, and miles driven.

The studies found the cell phone-fatality correlation to be true even when weighing in factors such as speed, alcohol consumption, and seat belt use.

Loeb and his co-author determined that, at the current time, cell phone use has a "significant adverse effect on pedestrian safety" and that "cell phones and their usage above a critical threshold adds to motor vehicle fatalities."

In the late 1980s and part of the 1990s, before the numbers of phones exploded, cell phone use actually had a "life-saving effect" in pedestrian and traffic accidents, Loeb notes.

"Cell-phone users' were able to quickly call for medical assistance when involved in an accident. This quick medical response actually reduced the number of traffic deaths for a time," Loeb hypothesizes.

However, this was not the case when cells were first used in the mid-1980s, when they caused a "life-taking effect" among pedestrians, drivers and passengers in vehicles. In those early days, when there were fewer than a million phones, fatalities increased, says Loeb, because drivers and pedestrians probably were still adjusting to the novelty of using them, and there weren't enough cell phones in use to make a difference in summoning help following an accident, he explains.

The "life-saving effect" occurred as the volume of phones grew into the early 1990s, and increasing numbers of cells were used to call 911 following accidents, leading to a drop in fatalities, explains Loeb.

But this life-saving effect was canceled out once the numbers of phones reached a "critical mass" of about 100 million and the "life-taking effect" – increased accidents and fatalities -- outweighed the benefits of quick access to 911 services, according to Loeb.

He and his co-authors recommend that governments consider more aggressive policies to reduce cell phone use by both drivers and pedestrians, to reduce the number of fatalities.

Two other studies of pedestrian safety found that using a cell phone while hoofing it can endanger one's health. Older pedestrians, in particular, are impaired when crossing a busy (simulated) street while speaking on a mobile phone, the researchers found.

However, the walking hazard that reduced pedestrian safety was cell-phone use but not music.

The studies, in which participants crossed a virtual street while talking on the phone or listening to music, found that the music-listeners were able to navigate traffic as well as the average unencumbered pedestrian.

Users of hands-free cell phones, however, took longer to cross the same street under the same conditions and were more likely to get run over.

Older cell-phone users, especially those unsteady on their feet to begin with, were even more likely to become traffic casualties.

"Many people assume that walking is so automatic that really nothing will get in the way," said University of Illinois psychology professor Art Kramer, who led the research with psychology professor Jason McCarley and postdoctoral researcher Mark Neider. "And walking is pretty automatic, but actually walking in environments that have lots of obstacles is perhaps not as automatic as one might think."

The first study, in the journal Accident Analysis and Prevention, found that college-age adults who were talking on a cell phone took 25 percent longer to cross the street than their peers who were not on the phone. They were also more likely to fail to cross the street in the 30 seconds allotted for the task, even though their peers were able to do so.

Each participant walked on a manual treadmill in a virtual environment, meaning that each encountered the exact same conditions – the same number and speed of cars, for example – as their peers.

The second study gave adults age 60 and above the same tasks, and included some participants who had a history of falling. The differences between those on and off the phone were even more striking in the older group, Kramer said.

"Older adults on the phone got run over about 15 percent more often" than those not on the phone, he said, and those with a history of falling fared even worse.

"So walking and talking on the phone while old, especially, appears to be dangerous," he said.

Bibliography - Sources

1. Rutgers University
2. Transportation Research, "The cell phone effect on pedestrian fatalities",
3. New Jersey City University)
4. Applied Economics, "The impact of cell phones and BAC Laws on Motor Vehicle Fatality Rates"
5. National Highway Traffic Safety Administration
6. University of Illinois at Urbana-Champaign
7. Accident Analysis and Prevention