A Technology Transfer Success Total Station Use for Accident Investigation RESEARCHERS DOCUMENT HOW THE USE OF TOTAL STATION SURVEYING EQUIPMENT (TSSE) BY THE WASHINGTON STATE PATROL HAS PROVED SUCCESSFUL AT REDUCING ACCIDENT INVESTIGATION TIME AND SPEEDING INCIDENT CLEARANCE

INCIDENT CLEARANCE. INCIDENTS INCLUDING VEHICLE accidents, breakdowns or spills, result in a substantial amount of vehicle delay. Incident-induced vehicle delay typically comprises three components: (1) the travel lane that previously provided vehicle throughput may be blocked; providing no vehicle throughput, (2) vehicles in the adjacent lane may travel at reduced speeds (reducing vehicle throughput) because of the presence of emergency personnel or curiosity, and (3) vehicles upstream of the blockage may slow and queue as they try to change lanes. Nationally, incidents have been estimated to result in 1.3 billion vehiclehours of delay at a cost of nearly $10 billion.1 Additional costs may result from secondary incidents upstream if drivers are required to stop or maneuver suddenly or downstream if drivers use excessive speed to make up for lost time. To reduce delay costs and improve the level of safety at or near the incident scene, methods must be employed that minimize the time that the incident is on the roadway but do not compromise safety or interfere with law enforcement procedures. Technology can be considered as one -. of the important factors, such as congestion and public pressures, in driving change in transportation.2 The use of total station surveying equipment (TSSE) by the Washington State Patrol in the greater Seattle area has proved successful at reducing accident investigation time and speeding incident clearance. The Washington State Department of Transportation (WSDOT) took a national leadership role in the investigation and implementation of this technology. Afier WSDOT documented the success of this application, interest in using TSSE for accident investigation developed across the country. The reseatch report “The Use Of Total Station Surveying Equipment For Accident Investigation: A NationaJ Perspective”3 more fully documents the success of the technology’s transfer to other parts of the country. While the protection of life and property is of highest priority, police agencies are also typically responsible for accident investigation, Investigation-related duties include: (1) identi&lng any suspicious or illegal activity (e.g., illegal use of alcohol or other drugs, felony involvement) and (2) diminishing the potential for a liability dispute (i.e., subject to court action). Police troopers document all pertinent physical evidence and details at the accident scene. Such documentation may include (1) a description of the roadway and surrounding environment (e.g., locations of intersections, beginnings and ends of curves, warning signs), (2) a description of each vehicle’s movement (e. g., direction of travel, speed, unusual movements, changes in direction), and (3) a description of other pertinent details such as the beginning and end of skid marks, debris patterns, gouges and scratches. The time required to document this information varies greatly, depending on the magnitude and severity of the accident. Traditional methods of collecting physical evidence at an accident scene require a stationary reference and a means for measuring distance between an object and the reference. The two most common methods, aside from TSSE, for collecting physical evidence include the triangulation method and the coordinate method. Photographs or videotape may also be used to further document the scene. In the ofice, the accident is recreated, again by hand, relying on the field notes and measurements. To speed the documentation process, some accident investigation agencies are initiating the use of total station surveying equipment. TSSE uses an infrared