In-Vehicle Phone Use Erodes The Margin of Driving Safety Especially for Older Drivers


Hancock, P.A., Lesch, M., Simmons, L., Smither, J., &Mouloua, M. (2002). In-vehicle phone use erodes the margin of driving safety especially for older drivers. Gerontechnology, 2(1), 124-125.

There is significant contemporary concern for the safety effects of mobile phone use during driving. However, it is as yet unresolved as to whether and to what degree, such usage increases collision frequency. We have argued that such uncertainty arises from the fundamental nature of driving which oscillates between a totally attention demanding task to an automated, over-learned response. To evaluate the safety impact of phone use while driving therefore, it is necessary to examine drivers’ reactions during critical driving maneuvers when there attention is fully engaged. This report details such a critical evaluation. On a controlled test track facility we evaluated the performance of forty-two licensed drivers who were evenly split between male and female participants and between an older and younger group. These drivers were required to respond to an in-vehicle phone at the same time that they were faced with masking a crucial stopping decision. Of primary importance, we found a critical 15% increase in red light violations in the presence of the phone distraction task. This compliance the red-light activation was modified by driver age such that older individuals were disproportionately disadvantaged by the presence of the distraction. In addition to compliance, which represents drivers’ ability to recognize the presence of the red light, we also noted a showing of reaction in case where drivers did recognize the critical red light activation. For example, we found a 36.5% increase in the average time to activate breaking and even though drivers tried to compensate for their late response by increased intensity of breaking, we still found a 47.6% decrease in safety margin as represented by stopping distance in front of the light. These combined results indicate that drivers miss more critical external signals in the presence of phone distractions but also show that even when they are aware of critical external demands for stopping, they are much more inefficient in response. The apparent simplicity of driving hides a fundamental complexity that means that it is not possible to specify a simplistic relationship between these distraction effects and outcome crash patterns. However, we can conclude that in-vehicle phone use erodes performance safety margin to a significant and disturbing degree. how such a safety margin can be restored by improved in-vehicle device design is a crucial objective of the transportation telematics enterprise.

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