Effects of Distraction Type, Driver Age, and Roadway Environment on Reaction Times – An Analysis Using SHRP-2 NDS Data

Effects of different types of cell phone use were examined through an analysis of selected data from the SHRP2 Naturalistic Driving Study (NDS). Driving events involving lead-vehicle or approaching-vehicle incidents were analyzed to compare driver reaction times and crash probability across driver distraction type, driver age, and roadway environment. The analysis found that the median reaction time was 40.5% higher among drivers engaged in a visualmanual task such as texting, and crash risk for those drivers was 4.66 times higher compared to drivers who were undistracted. Median reaction times in urban environments were longer than those in freeway environments. Drivers aged 1619 exhibited faster reaction times then older drivers, but higher crash risk.