Accident reconstructionists and collision investigators are often asked to reconstruct vehicle collisions with respect to the speeds and dynamics of the vehicle(s), cyclist(s), and/or pedestrian(s) involved. Most often, the reconstructionist and investigator are also asked to determine if the collision was avoidable. One of the challenges in a collision avoidance analysis is determining a reasonable perception-response time (i.e., the time required for the through driver to detect, perceive, and begin an evasive maneuver in response to the pedestrian) given the circumstances involved in the incident case.
In the following peer-reviewed, scientific publications, we take a closer look at driver response times (DRTs) in historically under-researched collision scenarios to determine relevant and useful DRT values.
Straight intersecting path or “side” collisions account for 12% of all motor vehicle crashes and 24% of fatalities. While previous research has examined driver responses to hazards striking from the right (near side), no research has quantified driver responses to hazards striking from the left (far side) of an intersection. In this study we examine the driver response time (DRT) of drivers confronted with a left-incurring hazard at an unsignalized intersection.
Previously researched path intrusion scenarios include left-turning hazard vehicles which intrude laterally across the path of the through driver. A right turning vehicle, however, creates a scenario where a hazard which was initially travelling perpendicular to the driver can intrude into the through driver’s path without also occupying the adjacent through lanes. This hazard scenario has not been previously investigated. The purpose of this research was to determine driver response time (DRT) and response choice to a right turning vehicle that merges abruptly into the lane of the oncoming through driver.
Motor vehicle crashes with cyclists are on the rise in the USA. Although some research exists on the response time of drivers to some types of path intrusions, data on the perception-response of through drivers to cyclists who fail to stop at a stop sign and ride into the path of the vehicle has not been researched. The purpose of this study was to quantify the driver response time (DRT) to a cyclist that intrudes perpendicularly in front of a through vehicle at an intersection where the driver has the right-of-way.
Left-turn crashes account for almost one quarter of all collisions. Although research has quantified the response time of drivers to left-turning vehicles with high acceleration profiles, research is lacking for driver responses to realistic left-turning vehicle acceleration. The purpose of this research was to determine the driver response time (DRT) to a left-turning vehicle from the first lateral movement of the left-turning vehicle.
Vehicle-pedestrian collisions account for 15% of fatal crashes in the USA, and there has been an increase in fatal crashes in the USA from 2006 to 2015. Although research exists on the response time of drivers responding to pedestrian path intrusions, data on the response time of through drivers to jaywalking pedestrians crossing from the far side of the road has not been determined. Therefore, the purpose of this study was to quantify driver response time (DRT) to a pedestrian that intrudes perpendicularly into the path of a vehicle from the far curb (adjacent to oncoming traffic).
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