Predictors of older drivers' involvement in high-range speeding behavior

ABSTRACT

Objective: Even small increases in vehicle speed raise crash risk and resulting injury severity. Older drivers are at increased risk of involvement in casualty crashes and injury compared to younger drivers. However, there is little objective evidence about older drivers' speeding. This study investigates the nature and predictors of high-range speeding among drivers aged 75–94 years.

Methods: Speed per second was estimated using Global Positioning System devices installed in participants' vehicles. High-range speeding events were defined as traveling an average 10+km/h above the speed limit over 30 seconds. Descriptive analysis examined speeding events by participant characteristics and mileage driven. Regression analyses were used to examine the association between involvement in high-range speeding events and possible predictive factors.

Results: Most (96%, 182/190) participants agreed to have their vehicle instrumented, and speeding events were accurately recorded for 97% (177/182) of participants. While 77% (136/177) of participants were involved in one or more high-range events, 42% (75/177) were involved in greater than five events during 12-months of data collection. Participants involved in high-range events drove approximately twice as many kilometres as those not involved. High-range events tended to be infrequent (median = 6 per 10,000 km; IQR = 2–18). The rate of high-range speeding was associated with better cognitive function and attention to the driving environment.

Conclusion: This suggests those older drivers with poorer cognition and visual attention may drive more cautiously, thereby reducing their high-range speeding behavior.

KEYWORDS:

• Older drivers
• speeding
• cognition
• vision
• confidence
• naturalistic driving

Acknowledgments

The authors thank the study participants, without whom this study would not have been possible. The authors would like to acknowledge the in-kind support from NRMA Motoring for participant recruitment through letters of invitation sent to members. Claire Allan, Laura Peattie, Freya Saich, and Rachelle Mason were also involved in data collection.

Funding

This research was funded by an Australian Research Council Discovery Project, a University of Sydney Equipment Grant (DP110101740), IRT Foundation, and the Centre for Road Safety at Transport for NSW. Anna Chevalier is the recipient of an NRMA-ACT Trust scholarship. However, the publication content has not been endorsed by, is not guaranteed by, and does not necessarily reflect the views of the NRMA-ACT Trust.