INVESTIGATION OF TRAFFIC DETECTORS FOR USE IN HAWAII


PI: Panos D. Prevedouros, Associate Professor of Civil Engineering
Collaborator: Lawrence Klein, Ph.D.
Assistants: Zhang Lin (Ph.D.), Matthew Chan (MSCE), Brad Takahashi (BSEE), Stephen Sung (BSEE), Katie Horgan (MSCE), Susan San (BA)

Sponsor: Highways Division, Hawaii DOT (20%) and Federal Highway Administration (80%) - HDOT Project Manager: Goro Sulijoadikusumo

Project Duration: May 2000 - December 2004

Currently the Hawaii DOT and Honolulu DTS conduct a number of counts for statistical purposes (Highway Performance Monitoring System mandate of the FHWA) as well as specific analyses and research. There is evidence that counts obtained without inductive loops are unreliable for statistical uses and clearly useless for the evaluation of TSM and ITS applications, or other measures that produce benefits in small increments because they contain large errors. In addition, on occasion loops became inoperable due to fatigue or construction. There is a need for alternative technology detectors which can provide continuous volumes counts with a better than 5% accuracy as well as measurements of speed and vehicle classification.

FHWA sponsored a study on "Field Test of Monitoring of Urban Vehicle Operations Using Non-intrusive Technologies" which tested passive and active infrared, passive magnetic, Doppler microwave, radar, passive acoustic, pulse ultrasonic and video detectors. The results of the study are informative but cannot be used by any state DOT for selection of detectors because: (1) It evaluated most technologies but fewer than half of the devices available; (2) Since the mid-1990s, many devices have undergone substantial improvement through ITS funding and field testing; (3) Some devices are no longer available or have been replaced; and (4) The study explicitly recommended that state DOTs select based on their requirements and priorities.

A detailed review of all the specifications of all detectors, including loops, is being conducted as part of this project. Special emphasis is given to detectors suitable for measurements on arterial streets and rural highways. Additional issues to be analyzed include the identification of detectors which are best suited for a Congestion Management System, the management of information produced by a large number of detectors collecting data around the clock for HPMS and other archival uses, maintenance requirements, potential efficiency gains and possible losses due to maintenance, and data reduction and analysis requirements.

This project includes tests of several portable and semi-portable detectors. This file provides a list of the detectors tested so far and this file provides a pictorial tour of sample field deployments.The links below provide instructions for the installation and basic data retrieval from the detector examined.

  • 3M microloops and Canoga
  • Spectra's ORADS portable laser sensor
  • RTMS and RTC of EIS
  • SEO's AutoSense II
  • Econolite's Autoscope
  • IRD fiber optic counter/classifier
  • Roadtrax BL piezoelectric sensors
  • Smartek SAS-1 acoustic sensor
  • JAMAR TRAX RD pneumatic tube sensor
  • Wavetronix SmartSensor

    Other sensors are added as the project progresses. Accuracy of volume, speed and classification counts under congested/uncongested, sunny/cloudy/rainy and day/night conditions are being investigated and reported.


    Last updated in August 2004.