Using the New SHRP2 Naturalistic Driving Study Safety Databases to Examine Safety Concerns for Older Drivers

US Transportation Collection2019PDFTech ReportKnodler, Michael A.Samuel, SibyGao, SongZafian, TracyAgrawal, RaviUniversity of Massachusetts at Amherst. Transportation CenterNew England Transportation ConsortiumUnited States. Department of Transportation. Federal Highway Administration Technology Deployment Initiatives and Partnership Program (TDIPP)Coordinated Technology Implementation Program (CTIP)University of Vermont. Transportation Research CenterNew England Transportation ConsortiumUnited StatesAged driversCognitionCrash ratesDriver trainingFatalitiesHealthLeft turnsSignalized intersectionsVisionNETCR114Final reportOlder drivers, age 65 and over, in the New England region have higher rates of crashes and of crash-related fatalities than middle-age drivers, and are especially over-represented in crashes occurring during left turns at signalized intersections. This study sought to learn more about the factors behind this trend, utilizing information from the SHRP2 (the second Strategic Highway Research Program) naturalistic driving study (NDS), and to assess the usefulness of NDS data for examining such research questions. NDS data were received for all trips with a driver age 65 and above, including signalized intersections with a crash or near crash event, as well as a sample of random baseline (non-eventful) trips. In the dataset, most of the older driver crashes were minor, with the most common crashes (over 70%) involving vehicles hitting a curb or leaving the roadway. Most of the statistically significant variables impacting whether an older driver crashed were related to their health and to visual and cognitive factors, which impact their ability to monitor oncoming traffic and to identify when there is a sufficient gap to safely make the turn. Training for older drivers to help them negotiate signalized intersections and left turns has shown to be beneficial by helping them adjust to their age-related limitations. The findings of this study, and the statistical significance of the results, were limited somewhat by the small number of crashes in the dataset.143