American Association of State Highway and Transportation Officials

Special Committee on Research and Innovation

FY2023 NCHRP PROBLEM STATEMENT TEMPLATE

Problem Number: 2023-G-12

Problem Title

National Traffic Sensor System Evaluation Program

Background Information And Need For Research

Traffic sensors are essential components of all highway traffic monitoring and traffic management systems. Traffic monitoring depends upon reliable vehicle detection and accurate measurement of traffic volume, speed, classification, and weight. Active traffic management systems and other intelligent transportation systems applications require these parameters and more, for varied uses like wrong-way driving detection, near-miss crash analysis, commercial vehicle screening, predictive analysis, and others.

Sensor systems based on new and emerging technologies—such as optics, electronics, communications, and artificial intelligence—are rapidly supplanting traditional traffic sensor systems, but they typically lack independent evaluation of their accuracy and performance. State and local agencies must often rely on informal, inconclusive evaluations and pilot deployments to assess sensor systems’ suitability for highway applications. The burden to test every sensor type and revision that comes to market creates massive duplication of effort and wastes time, effort, and funding.

Although millions of traffic sensors are in use, manufacturers and distributers can rarely provide independent third-party test results demonstrating their real-world performance. Sensor errors can seriously affect safety and mobility, particularly in critical traffic contexts. For example, the lack of quantified error rates and types introduces significant risk into use cases involving high traffic volumes and speeds. In addition, the lack of information regarding system performance and reliability in different operational domains can lead to misapplication of sensor systems, unacceptable performance, or short service life.

An authoritative method is needed to characterize the performance and identify the operational domains of current and emerging traffic sensor systems. AASHTO’s National Transportation Product Evaluation Program (NTPEP) has expressed interest in expanding into this type of evaluation. The research should develop test procedures that can be applied within the NTPEP or a similar program.

Literature Search Summary

Because a review of the TRID database revealed no innately similar traffic sensor evaluation programs, outreach was undertaken with industry leaders. Most cited ad hoc sensor validation by their own organizations or reliance on peer agency experiences. Recent research seems to be focused upon vehicle detection for freeway or signalized intersection applications.

The two-volume Federal Highway Administration’s Traffic Detector Handbook , was a comprehensive description of traffic sensor technology as of its 2006 publication date, but it does not address more recent technologies and did not propose a standard test methodology for traffic sensors. A 1997 study tested in-ground and overhead traffic sensor technologies, but it is now almost 25 years old. The Indiana Department of Transportation has adopted a basic test method for certain sensors. ASTM has established standards for traffic monitoring devices and weigh-in-motion systems , but they emphasize traffic monitoring rather than traffic management applications. The Federal Highway Administration is in the early phase of research to establish model systems engineering documents for traffic sensor detection systems (TSDS), which may be useful to the proposed work.

What appears to be lacking within the proposed topic is research on:

(1) sensors focused upon other modes of travel (e.g. pedestrians, bicycles, scooters, wheelchairs)

(2) use cases beyond traffic monitoring or basic count, occupancy, and signal call/extend functionality

(3) ways to consistently present test results that can be easily understood and compared

(4) a way to scale & extend the evaluation methodology to a repeatable, authoritative testing process that can be replicated by a geographically diverse network of laboratories.

A comprehensive literature review will be conducted as part of this research.

Research Objective

This research will examine current practice and needs, and then define a comprehensive traffic methodology applicable to traffic management and traffic monitoring sensor systems in each mode being detected (e.g. vehicle, pedestrian, bicycle, etc.). The test protocols will incorporate factors such as weather conditions, lighting and background, and traffic and roadway characteristics to characterize sensors’ operational domains. The methodology will allow testing laboratories to evaluate sensor systems with confidence that the methods and protocols are replicable, transferable, and ultimately useful to transportation agencies.

The research will also examine the feasibility of establishing a national testing program through either existing or newly created institutions and evaluate potential business models in consideration the needs and receptivity of transportation agencies and industry.

Urgency And Potential Benefits

Agencies lack a cost- and resource-effective way to assess real-world performance of traffic sensor systems over a spectrum of operational and environmental conditions prior to investing time, effort, and funding in demonstration pilots or fully operational deployments of traffic sensor systems. Too often sensor systems are overpromised and underdelivered for agencies’ multi-modal, multi-purpose applications. Cycles of revisions to address discovered deficiencies consume even more agency resources before sensors are deemed good enough.

Without this research, public agencies will be forced to rely on informal, resource-intensive, and often inconclusive evaluations to assess the performance of sensor systems for critical traffic control applications. The industry will continue to operate traffic sensors in environments and for applications for which they are not suited, resulting in unintended operational and safety problems.

Implementation Considerations

Traffic operations, safety, Intelligent Transportation Systems, and traffic monitoring staff at state and local agencies will be the biggest beneficiaries of this research and creation of an established testing program. Staff of the Georgia DOT, Utah DOT, Oregon DOT, City of Portland, Indiana DOT, Washington County, Oregon, and others have expressed their strong support for the proposed research. DOTs will be able to use the testing methodology and the testing program to more intelligently and confidently select sensor systems for specified applications, reducing cost while increasing effectiveness. The proposed methodology could be incorporated into AASHTO test methods.

To create awareness and facilitate implementation of the research results, the research team is expected to apply proven practices from similar test programs. The research should include workshops with a cross-section of agencies, vendors, regulators, and manufacturers involved in the production, evaluation, and use of ITS traffic sensor systems across a variety of safety and mobility-related use cases. AASHTO/TRB/FHWA outreach mechanisms can be used to broadly disseminate and market findings to support implementation.

As the sponsoring AASHTO Committee for this research proposal, the AASHTO Committee on Transportation System Operations will lead efforts to implement this research. The AASHTO Traffic Engineering committee, the Institute of Transportation Engineers (ITE), Federal Highway Administration, and several state and local transportation agencies have expressed support for this research and its implementation.

Recommended Research Funding And Research Period

Research Funding: Required research funding is expected to be $600,000.

Research Period: 30 months. The research time estimates for this problem statement are:

• 21 months to perform the research

• 9 months to engage in communication and outreach efforts.

Problem Statement Author(S): For each author, provide their name, affiliation, email address and phone.

• David Hirsch, Oregon DOT, 541-604-4977, david.hirsch@odot.state.or.us

• Shaun Quayle, Washington County, OR, 503-846-7938, shaun_quayle@co.washington.or.us

• David Huft, South Dakota DOT, 605.773.3358, dave.huft@state.sd.us

Potential Panel Members: For each panel member, provide their name, affiliation, email address and phone.

• Darcy Bullock, Purdue University 765.494.2226 darcy@purdue.edu

• Mark Taylor, Utah DOT 801.887.3714 marktaylor@utah.gov

• Jianming Ma, Texas DOT 512.506.5106 jianming.ma@txdot.gov

• Lawrence A. Klein, Klein & Associates 714.356.2275 larry@laklein.com

• David Huft, South Dakota DOT, 605.773.3358, dave.huft@state.sd.us

Person Submitting The Problem Statement: Name, affiliation, email address and phone.

Galen McGill

Oregon Department of Transportation

AASHTO CTSO Research Coordinator

Phone number: (503) 986-4486

Email address: galen.e.mcgill@odot.state.or.us