Andy Lam

SAFETY EVALUATION RESULTS FROM THE FIELD OPERATIONAL TEST OF AN INTELLIGENT CRUISE CONTROL (ICC) SYSTEM

This paper describes the safety evaluation results from a Field Operational Test (FOT) of an Intelligent Cruise Control (ICC) system. The primary goal of this evaluation was to determine safety effects of the ICC system. Safety surrogate measures were established and examined for normal driving situations as well as for safety-critical situations. It was found that use of the ICC system in the FOT was generally associated with safer driving compared to manual control and is projected to result in net safety benefits if widely deployed. (A) For the covering abstract see ITRD E106371.

THE APPLICATION OF STATE SPACE BOUNDARIES IN THE SAFETY EVALUATION OF COLLISION AVOIDANCE SYSTEMS

This paper describes how the state of space boundaries from field operational test data can be used to evaluate the potential benefits of longitudinal collision avoidance systems. The state space boundary metric provides an enhanced measure of relative hazardousness. It integrates measures related to range, range rate, and deceleration level. This allows for more direct safety inferences to be made particularly in pre-crash scenarios.

Naturalistic Study of Truck Following Behavior

A baseline case was created for the following behavior of heavy-truck drivers with the use of naturalistic driving data to support the development of automated platooning. A truck platoon is a string of trucks following each other in the same lane at short distances. Grouping vehicles in platoons can increase capacity on roads, save significant fuel, reduce emissions, and potentially result in improved safety. However, these benefits can be realized only if the platoons operate in an automated, coordinated manner. Because little literature of truck following behavior exists to support the development of such truck platoons, this research focused on how closely trucks follow other vehicles on highways under various environmental conditions, how closely a truck follows a leading vehicle when other vehicles cut in between, and the safety impact of following at different headways. Findings indicate that trucks follow other vehicles at an average headway of about 2 s overall, and those headways are shorter when following a passenger car rather than a heavy truck, on state highways rather than on Interstates, in clear weather rather than in rain or snow, and during the day rather than during at night. Vehicles usually do not cut in when a truck is following another vehicle at less than 25-m (82-ft) or 1.0-s headway. For manual response times, the rear-end crash risk increases considerably at headways of less than 1.0 s; for automated response times, crash risk is almost negligible at headways as low as 0.5 s.

Effects on Drivers’ Behavior of Forward Collision Warning System Alerts:

Forward collision warning (FCW) systems have been available for some time. Drivers 20-29 years of age are especially at risk for being involved in motor vehicle crashes due to distraction. (FCW) systems could potentially reduce rear-end crashes caused by distraction and other factors. A field operational experiment was run to determine whether FCW systems could reduce over time for this cohort the driving conflicts (rear-end crashes and near crashes) with lead vehicles. Information was gathered on 38 drivers over varying periods of time (up to a year) on alert rates [over vehicle miles traveled (VMT) or months], conflict rates, and responses to conflicts. Conflicts per 1,000 VMT decreased by 76.6%. The decrease in conflict rates was correlated with the decrease in alert rates (0.71), suggesting that drivers were responding positively to the alerts. There was no change in the responses to conflicts. Females had many fewer alerts than males.