Field Performance Evaluation of Autosense Axle Counter at Leesburg Mainline Plaza

摘要

The Florida Department of Transportation (FDOT) Florida's Turnpike Enterprise retained CUTR to evaluate the functionality, capability and accuracy of Autosense Axle Counter (Trademark) (ASAC). ASAC is a diode-laser-based vehicle detection and classification sensor manufactured by Schwartz Electro-Optics (SEO) of Orlando. The device is ideally located on a pole alongside the highway or alongside a toll lane, pointing downward toward the center of the traffic lane. ASAC is mounted five feet above the road surface and emits two laser beams at a fixed angle separation of ten (10) degrees onto the pavement. As a vehicle passes the device, the laser beams are broken and the device is able to generate a series of two-dimensional scans of the vehicle. Once the vehicle has passed fully through the beams, a three dimensional image of vehicle is developed. This image is used to count the axles using in-built device algorithms. This device had the multiple capabilities: to detect, to separate and to classify vehicles. The evaluation took place at Leesburg Mainline Toll Plaza on the Florida Turnpike. The data used in this report included the information dating form May 17-July 14, 2002, with a sample size of 30,535 vehicles. The objective of the evaluation was to assess the accuracy of ASAC as a vehicle classifier and separator. The ASAC device evaluated in this report was a prototype.