California Department of Transportation

Sensors Research and Evaluation

Accurate and timely traffic data is necessary many functions:

  • To use in PeMS to measure the before/after performance of Construction, Maintenance, and Operations Projects

  • To provide travelers with travel time information

  • For effective real time operation of the system

  • For a most ITS functions

Consequently, DRI is developing a full complement of projects focused on both the evaluation and optimization of existing roadway detectors and the development of more cost effective new detectors. We will be reporting on new methods to collect higher quality data from loop stations, Radar detectors, wireless pan-tilt-zoom camera systems, and many other related projects as time and web bandwidth allow. Check back to this site for updates. Below is a brief introduction to two of these projects.

Developing New Sensors

Perhaps the most promising new out-of-pavement detector being developed is one DRI just patented. This has high potential to meet a multitude of functional requirements (high accuracy, easy wireless deployment, etc.) once fully developed, but there are still technical challenges before this unit will be widely available. Learn more about it here.

Evaluating Existing Sensors

Equally important as the development of the next generation of sensors is providing better tools for evaluating and diagnosing the current generation. DRI is spearheading the Caltrans Detector Evaluation Technology Team (DETT) by developing a portable detector evaluation station to be used in site selected by DETT in D7 (Los Angeles). This portable system has been designed with low cost commercial off the shelf (COTS) components, so as to be available to all districts.

DRI is also evaluating commercial Sidefire detectors at the newly completed I-405 detector evaluation facility in D12 that just came online. This testbed has unique capabilities, and it also has full time staffing, budget, etc. Both the capabilities and initial results from the I-405 facility evaluations will be reported elsewhere on this DRI site as confirmed results become available.

The portable detector evaluation system being developed by DRI should allow the assessment of any detection station anywhere. The utility of a given detector for a given application can be very much a function of the roadway geometry, mounting, placement, traffic, and other conditions, which vary from site to site. Hence, DRI has designed the system to be low cost, portable, and simple to use. Unlike the I-405 testbed (above), this system is currently being developed on a shoestring budget only using overhead staff time, but does have some interesting potential.

Portable Detector Evaluation System

This portable detector evaluation system should be useful for a number of applications:

  • To "Ground truth" the accuracy of the speed, volume, and occupancy data for existing loop stations
  • Help troubleshoot loop stations and optimize them for better accuracy
  • "Ground truth" the accuracy of the speed, volume, and occupancy data for deployed Radar and other types of detection stations
  • Help set up and optimize the placement and calibration of Sidefire Radar stations
  • Provide a portable a portable count station for temporary use
  • Provide a portable a Pan Tilt Zoom camera station for temporary use

There are three primary parts to this system: