TRIENNIAL STRATEGIC PLAN

TRB Committee on Highway Traffic Monitoring

Evaluation Period: February 1, 2006 to January 31, 2009

1. Name and Scope

Committee Name: Highway Traffic Monitoring – ABJ35

Committee Scope: This committee is concerned with all aspects of research in the fields of highway traffic monitoring, including detection, counting, classification, and in-motion weighing of highway vehicles. Its scope encompasses the full range of monitoring technology, including traffic sensors (both intrusive and non-intrusive), installation materials and techniques, signal processing algorithms, analysis and reporting techniques, and comprehensive monitoring programs. The committee is also concerned with highway monitoring standards to ensure the applicability and quality of traffic data in all its applications.

During the Evaluation Period the Committee moved from the Pavement Management Section (AFD) to the Data and Information Systems Section (ABJ), and the scope was broadened in order to bring it in line with the activities of the committee. Here is the scope that was changed:

Previous Scope: This committee is concerned with all aspects of research in the fields of in-motion weighing, counting, and classification of highway vehicles. Its stimulation and dissemination functions may extend to dynamic vehicle axle loadings and automatic vehicle identification, as well as other areas to improve the accuracy of vehicular flow estimates; it will also extend into the application of weigh-in-motion technology and the utilization of data therefrom in the design and reconstruction of pavements and structures.

An issue that remains is to clarify the focus of the committee from that of the Operations Section (AHB) concerning the various ways in which traffic data derived from operations are used. For example, research papers about improved traffic operations which use data from traffic detectors installed for operational purposes would not normally be considered part of the ABJ35 scope. Another question is the extent to which the use of probe vehicles is included in the scope.

The committee has two subcommittees, which are important means of conducting committee business. The first one is a joint subcommittee with the Urban Transportation Data and Information Systems Committee (ABJ30):

Subcommittee Name: Archived Data User Service (ADUS) – ABJ35(1)

Subcommittee Scope: The scope of this subcommittee includes all aspects of the archiving and management of highway traffic data collected via intelligent transportation systems (ITS) and other systems designed for traffic operations. The focus is on the management of data over time: data transfer, fusion, structure, storage, documentation, dissemination, etc. for analysis of variations, trends, patterns, etc. This is incorporated in the National ITS Architecture’s Archived Data User Service (ADUS).

A second subcommittee was formed in 2008:

Subcommittee Name: Weigh-in-Motion (WIM) – ABJ35(2)

Subcommittee Scope: This subcommittee is concerned with all aspects of research into weigh-in-motion (WIM) of highway vehicles. Its functions extend to WIM sensors and systems, dynamic vehicle axle loadings, and the applications of WIM data. It includes vehicle classification in so far as WIM is used to classify vehicles.

2. Critical and Cross-Cutting Issues

Highway traffic monitoring is by its nature a cross-cutting activity. The data and information derived from traffic monitoring are used throughout surface transportation. Several uses of traffic monitoring data and information are critical to transportation, including policy development, planning, safety analysis, and performance management.

3. Membership and Meetings

The committee has 29 members distributed as follows:

6

6 academic
3 emeritus
2 federal government
2 international
9 private sector
1 research institute
4 state government
2 young

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The subcommittees do not distinguish between members and friends. The ADUS Subcommittee has a roster of 69 people and the WIM Subcommittee has a roster of 32 people.

2007 Annual Meeting:
Attendance: 15 members and 25 friends
Papers: 32 reviewed, 8 presented, 7 recommended for publication

2008 Annual Meeting:
Attendance: 19 members and 25 friends
Papers: 34 reviewed, 23 presented, and 8 recommended for publication

2009 Annual Meeting:
Attendance: 18 members and 22 friends
Papers: 35 reviewed, 16 presented, and 8 recommended for publication

The ADUS Subcommittee sponsored workshops at the annual meetings in 2007, 2008, and 2009.

The committee also met during the North American Travel Monitoring Exhibition and Conferences (NATMEC) held in 2006 and 2008. Attendance at these mid-year meetings by personnel from state highway agencies was significantly higher than at the annual meeting. A continuing challenge of the committee is to include the participation of state personnel engaged in traffic monitoring who have difficulty getting permission to travel out of state. For this reason the committee does not usually have a mid-year meeting unless it is held in conjunction with a conference or workshop that a number of its members and friends are attending.

4. Interactions

The committee has jointly sponsored sessions with committees from the Pavement Management Section and the Data and Information Systems Section. Through the committee’s close association with the Task Force on Traffic Monitoring Conferences (AJB25T), the committee has jointly sponsored sessions with the Freeway Operations Committee (AHB20). The committee and its subcommittees maintain liaisons with other committees, notably, the Motor Vehicle Size and Weight Committee and committees from the Pavement Management Section, the Operations Section, and the Data and Information Systems Section.

Liaisons should be considered with other committees, in particular, the Safety Data, Analysis and Evaluation Committee (ANB20) because of the need for good travel data for safety analysis and the Motorcycles and Mopeds Committee (ANF30) because of the special challenge of collecting travel data for motorcycles. There may be opportunity to work with operations committees involved in active traffic management, an emerging area which requires substantial improvement in traffic data systems.

5. Research Needs

The committee has submitted several research needs statements (RNS) to the TRB Research Needs Database:

  1. Impact of Axle Configuration on Vehicle Classification Accuracy
  2. Improving Motorcycle Detection and Count Data
  3. Weight vs. No Weight Vehicle Classification
  4. An Assessment of the Quality of Vehicle Classification Data and a Demonstration of How It Can be Measured and Improved to Support the Mechanistic-Empirical Pavement Design Guide (MEPDG)
  5. Evaluate the Feasibility of Using Multiple Sensor Weigh-In-Motion (WIM) Systems to Alleviate Errors Caused by Pavement Roughness or Vehicle Dynamics
  6. Length-Based Vehicle Classification

The ADUS Subcommittee has identified these RNS:

  1. Using arterial street sensor data for performance monitoring
  2. Corridor management applications and model integration/validation issues
  3. Detailed considerations for transit vehicle location archives
  4. Identifying discretionary trip deviations/stops (quality control) from probe vehicle data
  5. Privacy issues and considerations associated with data archives
  6. Marketing existing ADUS standards

These NCHRP Synthesis Topics have been submitted:

  1. Short-term Traffic Counting Procedures
  2. Video Image Technology in Transportation Practice

A research need that the committee previously identified was funded by NCHRP: Project 07-16, “Recommended Revisions to the AASHTO Guidelines for Traffic Data Programs.” The report was published as NCHRP Report 618 and is presently undergoing review by AASHTO. A synthesis project that was discussed at the committee’s annual meeting in 2006 led to NCHRP Synthesis Report 386, “High Speed WIM System Calibration Practices.”

However, the NCHRP route has not usually been successful for funding traffic monitoring research. One route that has been more successful is the pooled-fund approach. For example, there is a series of three pooled-fund projects on “Evaluation of Non-Intrusive Traffic Detection Technologies.” There is a new pooled-fund project called “Loop and Length Based Classification” that incorporates RNS number 6 listed above.

A Small Business Innovative Research (SBIR) project entitled “Motorcycle Detection, Classification and Characterization” includes elements of RNS number 2 listed above.

6. Activity Plans

The committee plans to continue its close association with the NATMEC series of biennial conferences. While the committee usually does not have a mid-year meeting when there is no NATMEC, the committee will join the 2009 Joint Summer Meeting.

The ADUS Subcommittee is taking the lead in exploring the use of the Internet for its activities, such as starting a “wiki.” The WIM Subcommittee plans to hold two webinars in 2009: one on the influence of vehicle classification data on pavement design and another on WIM calibration.

In order to provide more focus to the papers submitted to the committee, the committee and subcommittees plan to issue calls for papers on particular topics. It is expected that the WIM Subcommittee will take a major role in the next International Conference on Weigh-in-Motion (ICWIM), which is expected to be held in the U.S. in 2012.

7. Future Goals

Priorities

1. Assisting agencies with understanding of traffic requirements for the MEPDG through dissemination of research findings on this topic will continue to be a priority for the group. Agencies are currently struggling with implementation, and methods by which available data can be aggregated to meet the needs of the program (Load Spectra, Truck Traffic Classification, etc). A planned webinar on “Influence of Vehicle Classification Data on Pavement Design” is part of the committee’s response. A call for papers or panel discussion is also expected.

2. Accurate counting and classification of vehicles has grown in area of concern, as traffic patterns appear to be changing from historical norms. Evidence suggests that growth rates have been in decline for years, and we are now seeing negative growth in some areas. Impacts on many related areas, including forecasting of needs, revenue generation, and others need to be evaluated. The ability to accurately count and classify vehicles has never been more important that it is now, and there are concerns that the equipment and software being used to accomplish this task aren't up to the challenge. Research needs to be focused on methods and tools for accomplishing this goal. At a minimum this should lead to a synthesis topic.

3. Algorithms for vehicle classification continue to struggle to accurately portray the vehicles using the roadways. Research should continue to address the need for better axle-based classification and new research should examine length-based classification, which is becoming more common. This could follow the “Loop and Length Based Classification” pooled-fund project referenced above. A call for papers would also focus attention on this topic.

4. For many purposes the distribution of traffic data collection equipment around the roadway network is wholly inadequate. Agencies generally have limited requests for weight data, but there are many requests for volume and percent truck information. A broader need for knowledge of the number of vehicles by general type is important for things such as accident rates, a critical statistic for safety considerations. Research needs statements will be developed to address how data can be effectively gathered on a broader array of sites, or how information may be reasonably imputed from data sites and assigned to others, to meet this high demand need.

5. Non-intrusive data collection technologies offer a number of key advantages in the collection of monitored traffic data, not the least of which are cost and safety. In addition to the “Evaluation of Non-Intrusive Traffic Detection Technologies” pooled-fund project reference above, research needs to continue to be focused on using and advancing these technologies to their greatest application.

Challenges

1. Agencies continue to struggle with manpower constraints in the traffic data management area. It is hard to maintain quality and timeliness in data submittals when people are not available to process data into usable information. A challenge to the committee will be to assist those charged with this responsibility by helping them find methods and tools that will make this task more efficient.

2. For the committee, all public and private agencies are closely scrutinizing costs, and pro bono work such as required to meet the needs of TRB and others is being discouraged more and more. Addressing the priorities and challenges will be a growing problem if participants are unable or unwilling to donate the time to it.

3. Resources for data collection are very limited so working with the data user community to secure adequate resources should help. However, this continues to be a challenge because of the diversity of data users and data requirements and the reluctance of users to pay for something that has not cost them in the past.

Opportunities for Collaboration

1. Traffic Monitoring committee intends to continue its support for the ADUS subcommittee jointly with the Urban Data Committee, as an emerging area of interest to many. The concept of storing and using data for multiple purposes remains economically attractive, if some substantial hurdles to implementation can be overcome. Addressing these challenges should be the continued focus of the ADUS Subcommittee.

2. Discussions related to traffic data needs for the MEPDG must include coordination with representatives of the design and construction community. Liaison activities must remain active with the Pavement Management committees to make sure that efforts in this area are focused where they need to be. Addressing these challenges should be a priority of the new WIM Subcommittee.

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