Speeding is a factor in approximately one-third of all motor vehicle fatalities. According to the National Highway Traffic Safety Administration, the number of speeding-related fatalities increased by 25 percent from 2013 to 2022. While speeding is a safety concern on all roads, rural and tribal roads experience disproportionally high traffic fatality rates and face added challenges with speeding. Managing speed and speeding behavior is a major challenge for state departments of transportation (DOTs) and their law enforcement partners.

America’s speeding problem is well documented. However, less is known about the relationships between speeding behavior, risk perception, driver workload, and key factors such as roadway features/characteristics. Although countermeasures to reduce speeding are implemented every year, the proportion of traffic fatalities that are caused by speed-related crashes has remained relatively the same in recent years. New research and countermeasures are needed to reduce the role of speeding in traffic fatalities.

Questions of interest to traffic safety professionals focused on speed management include:

·     When drivers perceive higher risk levels, do they select lower travel speeds? Is this true both within and between subjects? If so, is this consistently true across roadway characteristics?

·     Do drivers respond to higher cognitive workload by reducing speeds? Does higher cognitive workload increase perceived risk?

·     Which characteristics or combinations of characteristics result in drivers selecting lower travel speeds? Which of these can be implemented by jurisdictions seeking to reduce crashes and crash severity?

·     Do habitual speeders differ from other drivers in their responses to roadway characteristics, cognitive workload levels, and risk perception? Are there features that affect speed selection in habitual speeders?

·     What factors can jurisdictions use to convey accurate speed selection information to drivers on rural and tribal roads?

The objectives of this research are to (1) examine human factors considerations and driver speed selection on rural and tribal roads, with a focus on determining relationships among cognitive workload, perceived risk, roadway features, and speed selection, and (2) examine the above factors in habitual speeders. This research is intended to identify conditions under which speeding is more prevalent, thus helping DOTs and their law enforcement partners identify priority issues to address in reducing speeding. Results will also highlight conditions in which drivers are less likely to speed, or specifically in which they reduce their current speed in reaction to an aspect of the roadway design.