This study investigated risk factors associated with safety critical events occurring in a work zone. Naturalistic driving study (NDS) data was used to examine a first-hand view of crashes and near-crashes that occurred in and around work zones. NDS uses information related to driver behaviour and various non-driving related tasks performed while driving to assess the impact of driver behavior on crash risk. For context, the Federal Highway Administration reported that a crash occurs in a work zone every 5.4 minutes and that in 2015, 96,626 crashes occurred in work zones across the United States. There were three objectives for this study: (1) identify factors associated with risk of an individual driver being involved in a safety critical event in a work zone; (2) develop a logistic regression model to predict this risk; and (3) quantify risk for different factors using matched case-control design and odds ratio (OR).
The NDS data used for this study consisted of 36,103 crash, near-crash, and baseline events that represented various drivers and driving conditions. For each event there are 76 different variables, including driving behavior and construction zone. Work zone events represent 1.9% of the entire dataset, and all events were used in this study. Within this dataset, crash events represented 4.1% and near-crash events represented 7.7%, with the remaining 88.3% being baseline driving events.
The duration of a secondary task, driving behavior, traffic density, locality, traffic control, and lighting condition were significant risk factors for crashes and near-crashes in work zones. Results indicated that performing a non-driving secondary tasks (i.e., eating, talking, texting) for more than six seconds increases the risk of crashing or near-crashing by 5.46 times. Driver inattention is the most critical behavioral risk factor contributing to crashes or near-crashes. Researchers involved with the study suggest that the findings support a need to develop countermeasures, such as warning messages, to alert drivers when approaching a work zone.
Bharadwaj, N., Edara, P., & Sun, C. (2019). Risk Factors in Work Zone Safety Events: A Naturalistic Driving Study Analysis. Transportation Research Record, 0361198118821630.