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Comprehensive Truck Size and Weight Limits Study - Compliance Comparative Analysis Technical Report

Appendix C: Complete Project Plan

General Approach for this Task

This appendix provides the detailed project plan for USDOT's 2014 Comprehensive Truck Size and Weight Limits Study (2014 CTSW Study) Volume II: Compliance Comparative Analysis. The document is divided into five main sections:

  1. Detailed Project Plan for Part 1 (Desk Scan)
  2. General Approach for Part 3 (Estimation of Cost of Enforcement) and
    Part 4 (Effectiveness of Enforcement)
  3. Detailed Project Plan for Estimation of Cost of Enforcement
  4. Detailed Project Plan for Effectiveness of Enforcement
  5. Proposed Schedule for Completion

This part of the 2014 CTSW Study will focus on the identification of difference in methods and approaches, effectiveness of methods and approaches and costs associated with inspecting and conducting compliance assessments on trucks operating at or below current Federal truck size and weight limits as compared to conducting the same on trucks operating above those limits.  Two steps will be completed under this work:  making comparative assessments on the current fleet of trucks operating in the US and making similar comparative assessments on the "alternative configurations" that will be included in this Study.

As part of carrying out the responsibilities of included under this work, it is important to note that success in completing the proposed work hinges on the need to gather the necessary data supporting the technical analysis and assessments to be addressed under this part of the 2014 CTSW Study.

It is envisioned that the following data sources will be used to conduct the required work:

  • State Over-size/Over-weight Permitting Data:  In consultation with AASHTO's Sub Committee on Highway Transport, State permit data will be accessed and examined in order to identify trucks operating at or below current Federal size and weight limits and trucks that operate above those limits.
  • State Enforcement Plans: These plans provide state-specific data concerning resources (e.g., budget, personnel, facilities, equipment) directed at truck size and weight enforcement and information about the environment within which these resources are expended (e.g., extent of network, truck miles traveled).
  • Annual Certifications of Truck Size and Weight Enforcement database: This database contains state-specific information on the enforcement of commercial motor vehicle weight (by type of weighing method), violations (by type of violation), load shifting and off-loading requirements, and permit issuance activities.
  • Weigh-in-Motion data: WIM data from selected locations (subject to the criteria listed in Part 4) will provide a means to assess truck weight compliance by axle group and for the whole vehicle. The WIM data enable the calculation of the proposed performance measures (see Part 4).
  • Experiential data and intelligence: The work relies on extensive consultation with industry stakeholders. In particular, State representatives will be asked to provide experiential data to support our analysis. Case studies will be selected to investigate specific issues concerning compliance of alternative vehicle configurations in States where detailed data and/or substantial experience exist.

Part 1: Detailed Project Plan for Desk Scan

Literature Review

A comprehensive search of literature published in the last decade worldwide that will be helpful to this 2014 CTSW Study will be completed with a special focus on compliance and enforcement program costs and the effectiveness of enforcement. The principal objective of the search is to gain a thorough understanding of the current state of research and practice concerning truck weight enforcement and compliance. The literature search will include a variety of information sources: (1) engineering and scientific periodicals and journals; (2) conference proceedings; and (3) readily available government and industry reports. The starting point for this activity will be the final reports from NCHRP 20-07 Tasks 254 and 303. The American Association of State Highway and Transportation Officials (AASHTO) Subcommittee on Highway Transport (SCOHT) undertook Task 254 to summarize the activities associated with the international scan in 2006, and completed Task 303 in 2011 principally to respond to Federal truck size and weight study questions.

Beyond these initial resources, the search includes the resources shown below.

Library Catalogues and Conference Proceedings

  • Transportation Research International Documentation (TRID)
  • American Society for Civil Engineers
  • University of Michigan Transportation Research Institute Library
  • University of Manitoba Transport Information Group Library
  • ScienceDirect
  • NRC Research Press
  • Transportation Association of Canada

Heavy Vehicle Transport Technology Proceedings Government and Industry Agencies

  • Federal Highway Administration (FHWA)
  • Federal Motor Carrier Safety Administration (FMCSA)
  • The Transportation Research Board (TRB)
  • The Transportation Association of Canada
  • American Transportation Research Institute
  • National Transport Commission (Australia)
  • Australian Road Research Board
  • Organization for Economic and Community Development (OECD)
  • International Transport Forum (ITF)

The search will supplement the following list of key historical material with which we are already familiar:

  • Comprehensive Truck Size and Weight Study by the U.S. Department of Transportation, 2000 (2000 CTSW Study)
  • Relevant special reports by the Transportation Research Board, namely Special Report 267 Regulation of Weights, Lengths, and Widths of Commercial Motor Vehicles and Special Report 225 Truck Weight Limits: Issues and Options
  • Recent truck size and weight reports conducted in Maine, Vermont, Wisconsin, and Minnesota
  • Moving Freight With Better Trucks by the International Transport Forum
  • NCHRP Web Document 13 entitled Developing Measures of Effectiveness for Truck Weight Enforcement Activities
  • National Heavy Vehicle Enforcement Strategy Proposal by the National Transport Commission (Australia)

We envision summarizing the literature according to the following main topics:

  • Enforcement needs and approaches (including impacts of changes)
  • Enforcement costs
  • Enforcement benefits
  • Effectiveness of enforcement
  • Application and performance of enforcement technologies
  • Alternative approaches for achieving compliance

Stakeholder Data Gathering

To supplement the findings of the literature search, we will consult industry stakeholders representing enforcement and permitting programs from selected States, relevant committees within the Commercial Vehicle Safety Alliance (CVSA), AASHTO, and Transportation Research Board (TRB), and international experts from Canada, Europe, and Australia through various data gathering methods. The Appendix contains the areas of interest that we propose to use to guide the data gathering. To comply with the Federal Paperwork Reduction Act we will work through 4 AASHTO regions and through a CVSA Advisory Group of 9 States. Questions and requests for data will be coordinated through these organizations. We propose to include the following agencies (specific individuals are named where possible).

State Officials

Data will be gathered from officials from the following States and their counterparts. These States have been selected because they: (1) are considered to be enforcement programming leaders in the nation; (2) have experience in enforcing vehicles subject to grandfather provisions (e.g., Longer Combination Vehicles-LCV); and/or (3) have recently undertaken research and development projects related to truck size and weight enforcement.

  • Colorado (Mark Savage)
  • Florida (Keith Westphal)
  • Georgia (Gene Davis)
  • Idaho
  • Indiana (John Hill)
  • Maine (Rob Elder)
  • Michigan
  • Minnesota (Ted Coulianos, Tim Rogotzke, Bill Gardner, or Ward Briggs)
  • New Mexico
  • New York
  • Ohio (Jeff Honefanger)
  • Oregon
  • Utah
  • Vermont
  • Washington
  • Wisconsin (Peter Lynch or John Corbin)

Representatives from CVSA Committees

Data will be gathered from the following CVSA committee representatives and their State agencies:

  • Stephen Keppler, Executive Director
  • Size and Weight Committee: Jay Thompson, Chair (Arkansas Highway Police), Tim Levi, Vice Chair (Oklahoma Highway Patrol), and Allen Hook, Secretary (North Carolina State Highway Patrol)
  • Driver-Traffic Enforcement Committee: Thomas Fitzgerald, Chair (Massachusetts State Police)
  • Information Systems Committee: William Elovirta, Chair (Vermont Department of Motor Vehicles)
  • Vehicle Committee: Kerri Wirachowsky, Chair (Ontario Ministry of Transportation)

Representatives from AASHTO's Subcommittee on Highway Transport (SCOHT)

Data will be gathered from the following SCOHT members and their State agencies:

  • Mark Gottlieb, Chair (Wisconsin)
  • Jeff Honefenger, Vice Chair (Ohio)
  • Dan Breeden (Alaska)
  • Jay Thompson (Arkansas)
  • Alan Frew and Reymundo Rodriguez (Idaho)
  • Tommy Thames (Mississippi)
  • Jan Skouby (Missouri)
  • Gregg Dal Ponte (Oregon)
  • Glenn Rowe (Pennsylvania)
  • Carol Davis (Texas)
  • Anne Ford (Washington)

Representatives from TRB Committees

Data will be gathered from the following TRB committee representatives and their agencies and organizations:

  • Truck Size and Weight Committee (AT055), John Woodrooffe, Chair
  • Trucking Industry Research Committee (AT060), David Miller, Chair
  • Truck and Bus Safety (ANB70), Brenda Lantz, Chair

Representatives from Trucking Industry

Data will be gathered from the following trucking industry representatives and their organizations:

  • Trucking associations: American Trucking Associations (Darrin Roth), selected State Motor Truck Associations
  • Carriers: Landstar, Wal-Mart Transportation, FedEx Corp, ABF Freight Systems, Con-Way
  • Manufacturers: Volvo (Skip Yeakel)

International Experts

Data will be gathered from the following international experts and their organizations:

  • Anthony Germanchev, Australian Road Research Board
  • Jose Arrendondo, National Transport Commission (Australia)
  • Bob Pearson, PTRC (Australia)
  • John de Pont, TERNZ Transport Research (New Zealand)
  • Hans van Loo, Kalibra (Netherlands)
  • Loes Aarts, Ministry of Transport (Netherlands)
  • Bernard Jacob, IFSTTAR (France)
  • Paul Nordengen, Council for Scientific and Industrial Research (South Africa)
  • John Pearson, Council of Deputy Ministers of Transportation and Highway Safety, Ottawa, ON
  • David Bradley, Canadian Trucking Alliance
  • Rob Tardif, Ontario Ministry of Transportation
  • Darren Christle, Manitoba Infrastructure and Transportation, former CVSA President, and current Chair of the Standing Committee of Compliance and Regulatory Affairs of the Canadian Council of Motor Transport Administrators

It is envisioned that a summary of the findings from measurable data gathered from the stakeholders according to the same topics listed above for the literature review will be produced under this part of the 2014 CTSW Study. Findings from the data gathered will be clearly differentiated from literature findings, and will be attributed to the type of stakeholder (e.g., State official, researcher, international expert) generating the findings as possible. The results of the data gathering exercise will be summarized for internal purposes, and may also be reported as part of our deliverables. The information provides a valuable assessment (in addition to the literature) of the current state-of-the-practice.

Part 2: General Approach to Parts 3 (Enforcement Program Costs) and 4 (Effectiveness of Enforcement Programs)

A performance-based approach to estimate the costs of truck size and weight enforcement and analyze enforcement effectiveness will be applied. This approach considers enforcement program performance (or effectiveness) in terms of outputs (which reflect the way resources are used and what they are focused on: i.e., Axle, Tandem Axle, Gross Vehicle Weight and Bridge Formula violations, when conducting enforcement activities) and outcomes (which reflect the degree of success of the enforcement program in achieving compliance), as a function of resource inputs (for example, program costs). The distinction between outputs and outcomes, while subtle, is important because measuring outputs may encourage efforts to increase the quantity of inspections conducted or violations observed and reported, which ideally should decrease in situations where enforcement achieves better compliance. In contrast, outcome-oriented measures may describe the frequency or rate of compliant events (which may suggest successful enforcement) or the severity of over-weight observations (which may suggest a lack of enforcement success). Table 28 provides example measures within this approach.

Table 28: Example Measures within the Performance-Based Approach
Type of measure Example measure(s)

Input

  • Enforcement program cost
  • Number of enforcement personnel

Output

  • Inspections
  • Violations
  • Violation rate as a function of enforcement intensity

Outcome

  • Compliant events
  • Severity of over-weight axles

Application of this approach will provide the supporting framework for a multifaceted analysis designed to reveal insights about the costs and effectiveness of enforcement programs. It is acknowledged that a comprehensive, representative understanding of enforcement costs and effectiveness will be limited by the availability of reliable data. To accommodate these limitations and leverage existing datasets and institutional knowledge, a three-tiered approach will be pursued in completing the analysis for this part of the study as described below:

  • Tier 1: At the broadest level, relevant performance measures concerning enforcement costs (i.e., inputs) and activities (i.e., outputs) will be gathered at the State level using readily available data sources, supplemented through data gathered from industry stakeholders. The selection of States will be made considering general differences in trucking operations and varying geographic and climatic factors.
  • Tier 2: The assessment of compliance (i.e., an outcome) will analyze relevant performance measures at specific locations where representative data are available (principally, weigh-in-motion (WIM) data). This assessment enables a more detailed quantitative analysis of certain compliance outcomes (such as the proportion of compliant events or the severity of over-weight observations for specific truck configurations at that location), but constrains the ability to ascertain the effects of enforcement activities on these outcomes. Efforts will be concentrated on examining differences between trucks operating in excess of Federal limits and those operating below Federal limits. This Tier 2 deserves a little more explanation since it is the most complex. The level of compliance will be used as a way to measure enforcement effectiveness. Compliance will be measured by the degree of extremely over-weight trucks, measuring severity of over-weight axles and axle sets, and the proportion of compliant events, such as compliant axles and axle sets. The severity measure will be calculated as the average weight of all the over-weight observations and then how much this average exceeds the limit. This determination will be based on the configuration of trucks, which has weight implication and the weight limit based on classification. Using FHWA's vehicle classification scheme classes, as defined in the Traffic monitoring Guide, the Class 9 (five-axle tractor-semitrailers) will be used as the foundation truck but will also gather information on other classes 10-13 (six-axle tractor semitrailers and multiple trailer trucks), which include other configurations being considered for study. This information will be captured for those legally loaded and operating trucks and those extra-legal trucks in order to determine the proportion of compliant trucks within certain classifications at a specific WIM location. The extent to which this is information is aggregated along a corridor/in a region/in a State will be investigated as the study progresses. The determination of a specific enforcement activity related to these over-weight trucks will not be performed but will be useful in making observations toward trucks that are operating in over-weight conditions on these travel-ways. Special focus will be applied to Class 9 trucks and on specific, commonly observed "extra-legal" trucks operating under a "grandfathered provision" (for example, under a State-issued permit or a specific Federal size and weight statutory exemption).  For example, Longer Combination Vehicles (LCVs) allowed are allowed to operate, under the ISTEA-Freeze, in certain States at locations where they are known to be operating. Case study data will be examined from certain States where LCVs are allowed to legally operate and will be used to develop the adjustment factor for permits, and to help understand the compliance experience associated with trucks operating under a "grandfathered" right.
  • Tier 3: The third tier uses case studies to qualitatively investigate enforcement issues concerning alternative truck configurations that are too complex to handle at a larger scale. These case studies will be designed to support the quantitative assessment of compliance conducted in Tier 2.

The analysis approach described for Part 3 (Estimation of Cost of Enforcement) and Part 4 (Effectiveness of Enforcement) will also examine the integration of the alternative truck configuration and scenarios that are being developed for the 2014 CTSW Study as a whole. A more thorough framework for completing this integration will take shape as these scenarios are defined and clarified.

Part 3: Estimation of Cost of Enforcement

Part 3 determines and describes the inputs or resources required to manage and operate a State truck size and weight enforcement program (i.e., a Tier 1 analysis). Based on the findings from Part 2, inspection steps and procedures for the principal truck size and weight enforcement methods used in North America will be summarized, namely: (1) fixed (inspections occurring at static weigh scales, with or without a mainline pre-screening device); (2) roving (mobile officers conducting inspections using portable or semi-portable weighing devices); (3) virtual (inspections occurring using a combination of WIM and video/imaging technologies); and (4) compliance demonstration (where selected carriers are deemed responsible for compliance with all relevant matters, including weight, and are subject to auditing to assure compliance). This work focuses on the enforcement of truck size and weight limits; however, distinguishing enforcement resources directed at truck size and weight from those resources directed at safety or credentials regulations is not always easily performed. We will attempt to distinguish these program areas as far as practicable.

Truck size and weight enforcement program inputs will be gathered from selected State officials conducted as part of work to be addressed as described under Part 2 and summarized in a tabular format. Program inputs include:

  • Annual monetary cost (or budget) of the enforcement program;
  • Incremental costs of enforcement, weighings and other actions by configuration type of truck;
  • Number of enforcement personnel, the time spent conducting various enforcement activities, and the number of inspections (or weighings) by truck configuration performed by enforcement method;
  • Quantity of fixed and mobile enforcement equipment (e.g., scales or patrol cars); and
  • Quantity and type of automated enforcement technologies.

The data gathered will reveal information about the relative proportion of available resources directed at specific aspects of the enforcement program. Program aspects to be distinguished include routes and/or networks; industries and/or commodities; truck configurations (specifically those operating within Federal limits and those operating beyond Federal limits); and non-permitted versus permitted trucks. We expect that States may be unable to provide detailed breakdowns concerning some of these aspects; the level of detail available will dictate the specificity of subsequent analyses in Part 4 (Effectiveness of Enforcement).

Program cost figures for all States will be calculated from baseline information obtained from the annual certifications provided to FHWA, using staffing figures as a guide to the size of the program and adding the cost information, in proportion to staffing, obtained from selected States. This will help to normalize the data across States. Issues related to accuracy of proportional cost information will be reviewed with CVSA for quality control purposes. Additional normalization of the data will be accomplished through metrics such as highway network distance and truck miles of travel. Program costs will focus on any incremental costs (or cost savings) associated with enforcing regulations governing the alternative truck configurations currently operating in excess of Federal limits in certain States.

Key findings and trends will be summarized and used to assess the enforcement community's ability to sustain viable enforcement programs in the context of potentially expanded use of the alternative truck configurations on specified networks. For example, trends showing budget reductions over time, extra costs and/or time associated with certain methods of enforcement (for certain truck configurations or networks), or investments in new technologies will help assess program viability. This particular component of the analysis will be shaped by further characterization of the scenarios being developed in the other work areas.  In order to avoid highlighting States that could be boastful or need high levels of remedial action we plan to work with the States to consolidate findings on a regional basis or along certain corridors of the country.

To support the foregoing analysis, an investigation will be conducted into the costs and performance of existing and near-term enforcement technologies through gathering of experiential data from key technology users and vendors. Special attention will be given to the Smart Roadside Program that both FHWA and FMCSA have been promoting. This program is expected to be a key feature for improving enforcement effectiveness and future productivity. The virtual weigh station (VWS) initiative and wireless roadside inspection (WRI) technologies, two components of Smart Roadside, are already operating in several States across the nation. Although WRI is focused primarily on safety, any cost implications associated with truck size and weight will be captured in this cost analysis. Findings related to safety will also be considered and integrated into the work being completed in the Highway Safety/Truck Crash Analysis work are of this Project, as applicable.

Part 4: Effectiveness of Enforcement

Work to be completed under Part 4 will determine and describe the outputs and outcomes of enforcement programs and evaluates effectiveness by developing relationships between resource inputs and program outputs and assessing compliance outcomes. The proposed approach to meet the requirements of this area of the Project involves: (1) compiling and analyzing program outputs at the State level (i.e., a Tier 1 analysis); (2) assessing compliance outcomes using Weigh-in-Motion (WIM) data collected at representative locations (i.e., a Tier 2 analysis); and (3) conducting targeted case studies to identify enforcement issues associated with the alternative truck configurations (i.e., a Tier 3 analysis). In addition, we will identify statutes and regulations pertaining to Federal truck size and weight limits that would be impacted by regulatory changes.

Another important area of investigation included under this Part will be to determine the impact that the introduction of the "alternative configurations" included in this Study will have on the cost of enforcement programs and the impact on resource requirements needed to operate effective truck size and weight enforcement programs.  Outputs generated under the Modal Shift work area of this project will be used to define the boundaries for this assessment.

Analysis of Program Outputs

This component analyzes (at a Tier 1 level) weight enforcement program outputs, including:

  • Violations by type (i.e., axle weight, GVW, bridge formula);
  • Number of load shifting and offloading vehicles;
  • Over-weight permits issued by type (i.e., divisible vs. non-divisible, trip vs. annual); and
  • Violation rates, calculated as violations per number of inspections and number of vehicles weighed or by enforcement method.

The output analysis will be conducted on a State-by-State basis using the Annual Certifications of Truck Size and Weight Enforcement Activities dataset. Output measures such as overloads identified and avoided (e.g., through load shifting and/or offloading) are considered direct benefits of an enforcement program. Violations will be interpreted as observed incidents of non-compliance with all applicable size and weight laws and regulations.

An examination into the two relationships to further understand the effectiveness or performance of enforcement using these outputs and the inputs acquired in Part 3 (Estimation of Cost of Enforcement). The relationship between violation rate and inspection intensity (i.e., the number of inspections conducted per unit of time devoted to inspections), and between violation rate and enforcement intensity (i.e., the number of inspections conducted per unit of truck travel in a geographic region) will be established as part of this work. Previous research conducted in Canada reveals that higher inspection and enforcement intensities (related to traditional on-road activities) lead to lower violation rates, but produce an ever-diminishing return. Essentially, at some point, increases in intensity cause no further decrease in the violation rate. In addition, relevant States will be selected to gain more detailed analysis of these relationships. Specifically, information will be disaggregated by enforcement method (e.g., fixed vs. roving) and vehicle configuration to contribute to a more precise understanding of these relationships. The selection of States will be completed based on data availability (ascertained during the data gathering process) and directed at developing meaningful insights.

Assessment of Compliance Outcomes

Enforcement program effectiveness will also be evaluated based on its ability to meet its main objective: compliance. For this component, compliance is treated as an outcome within the performance-based approach. The compliance assessment occurs in the context of a Tier 2 analysis, as described earlier. Since directly measuring compliance is difficult, the approach to assessing compliance will be supported by using WIM data to provide an indication of compliance rates and the intensity of over-weight observations (level of over-weight) at selected locations.

The selection of WIM locations to include in the compliance assessment requires consideration of:

  • The WIM data requirements of other Reports, such as the pavement and bridge assessments included in the Project, so that quality control and pre-screening efforts can be minimized and standardized;
  • The calibration record of WIM equipment;
  • The quality and expected accuracy of WIM measurements, which varies by the type of WIM equipment;
  • The proximity of a WIM station to a weigh scale;
  • The availability of a full year of data to avoid seasonal bias;
  • The need to include WIM data representative of various truck operating, geographic, and climatic conditions;
  • The need to include WIM data representative of conditions on various highway networks (e.g., Interstate System, national network, etc.);
  • The ability to document the enforcement activities undertaken by the State in which the WIM is located (this will be assessed based on findings from Part 3 (Estimation of Cost of Enforcement); and
  • The ability to identify truck configurations from the WIM database that routinely operate under grandfather provisions, with the aim to isolate these from trucks that may operate under State issued over-size or over-weight permit.

At the selected WIM locations, specific configurations will be identified from the WIM dataset (using standard axle-based classification algorithms) and then analyze the weight data using the following performance measures:

  • Gross vehicle weight compliant, proportion: the fraction (or percentage) of the total observed truck sample which complies with the legal (static) gross vehicle weight limit.
  • Gross vehicle over-weight, severity: the extent to which average measured gross vehicle weights for the observed sub-sample of over-weight trucks exceeds the legal (static) gross vehicle weight limit.
  • Steering-axle compliant, proportion: the fraction (or percentage) of the total observed truck sample for which the steering-axle weight complies with the legal (static) steering-axle weight limit.
  • Steering-axle over-weight, severity: the extent to which average measured steering-axle weights for the observed sub-sample of trucks with an over-weight steering axle exceeds the legal (static) steering-axle weight limit.
  • Single-axle compliant, proportion: the fraction (or percentage) of the total observed truck sample for which all single-axle weight observations comply with the legal (static) single-axle weight limit.
  • Single-axle over-weight, severity: the extent to which average measured single-axle weights for the observed sub-sample of trucks with over-weight single axles exceeds the legal (static) single-axle weight limit.
  • Tandem-axle compliant, proportion: the fraction (or percentage) of the total observed truck sample for which all tandem-axle weight observations comply with the legal (static) tandem-axle weight limit.
  • Tandem-axle over-weight, severity: the extent to which average measured tandem-axle weights for the observed sub-sample of trucks with over-weight tandem axles exceeds the legal (static) tandem-axle weight limit.
  • Federal Bridge Formula-B compliant, proportion: the fraction or percentage of the total observed truck samples determined to comply with the Federal Bridge Formula.
  • Federal Bridge Formula-B violation severity:  the extent to which the average estimated bridge formula violations exceed the calculated value for each observed configuration that would deem it compliant.
  • Tridem-axle compliant, proportion (if applicable): the fraction (or percentage) of the total observed truck sample for which all tridem-axle weight observations comply with the legal (static) tridem-axle weight limit.
  • Tridem-axle over-weight, severity (if applicable): the extent to which average measured tridem-axle weights for the observed sub-sample of trucks with over-weight tridem axles exceeds the legal (static) tridem-axle weight limit.

To simplify the analysis, Class 9 trucks (standard five-axle tractor semitrailers) will be used as the base analysis vehicle for all locations. In addition, at certain locations, the truck configurations will be identified from the WIM database that routinely operate under grandfather provisions. Candidate truck configurations will be identified through consultation with State enforcement officials. Scoping the analysis to include only specific vehicle configurations minimizes the potential inclusion of permitted loads, which cannot be identified from the WIM data but which could be measured as over-weight despite being in compliance with permit conditions.

Performance measures listed previously will be used in order to define above as the basis for revealing insights about the compliance experience at the selected WIM locations. These insights will be shaped by knowledge gained about the enforcement practices and intensity in the State where the WIM is located. Specific findings concerning the effects of enforcement on compliance outcomes will be limited by the expected inability to attribute the intensity and type of enforcement activities to the specific WIM location. This issue, in addition to other uncontrolled variables, will also impact the ability to make direct comparisons of the compliance outcomes between WIM locations. Nevertheless, pragmatic insights will be drawn from the compliance assessment, and will select a sufficient number of WIM locations to generate and support these insights, subject to the selection considerations listed above.

When assessing truck weight compliance using WIM data, it is important to note two issues that arise because of the nature of the WIM measurements. First, WIM devices measure axle weights while trucks are in-motion and are therefore subject to the dynamic interactions between the vehicle and the road. As such, an over-weight observation by a WIM may not result in an over-weight observation if the same axle (or truck) is weighed on a static scale. Because of this, our analysis differentiates between an over-weight observation as recorded by a WIM and a violation, which normally arises from a static weighing with reference to a legal (static) load limit.

Second, because most WIM scales are not selective about the trucks they weigh (i.e., it does not target a vehicle for weighing based on the likelihood that it is over-weight), the proportion and severity of over-weight observations is representative of all trucks passing over the scale during the observation period. In contrast, the proportion and severity of over-weight observations at a static weigh scale could reflect targeting of trucks likely to be over-weight. By extension, it is incorrect to assume that the proportion of compliant vehicles observed at a WIM is the same as that observed at a weigh scale.

Case Studies of Alternative Truck Configurations

The case studies (Tier 3) investigate and document the enforcement and compliance experience associated with the alternative truck configurations not currently allowed nationwide but which are already in common use (under grandfather provisions or on State roads) in certain States. The investigation supports the quantitative compliance assessment of vehicles operating under grandfather provisions undertaken as part of this work by providing qualitative information obtained through in-depth data gathering. Specifically, we propose to review experiences with the 88,000 lb. five-axle tractor semitrailer (a candidate State for this project is Florida), the 97,000 lb. six-axle tractor semitrailer (this case study may focus on an industry sector, for example hauling of forestry or agricultural products), and LCVs operating in a number of western States or international jurisdictions (for example, States located west of the Mississippi and/or Canadian provinces). Each case study (up to three in total) will attempt to document any specialized or targeted enforcement activities or technologies directed at the alternative vehicle configurations and the results of these efforts within a specific operating context (e.g., in a State as a whole or within a specific industry sector).

Identification of Statutes and Regulations

In this work area, all statutes and regulations pertaining to Federal truck size and weight limits that would be impacted in the event of changes to these limits will be identified. The review will focus on relevant language contained in US Code Title 23: Highways and US Code Title 49: Transportation, as well as the corresponding regulations in the Code of Federal Regulations, Title 23, Part 658 and Code of Federal Regulations, Title 49 that pertain to Federal truck compliance program activities.  Consultation with State enforcement personnel responsible for the delivery of truck enforcement program activities will be conducted to ensure the appropriate Federal statutory and regulatory references are identified.

Appendix: Proposed Data Gathering Tools

As discussed in the body of the Project Plan, coordination with the four AASHTO regions (Western Association of State Highway and Transportation Officials [WASHTO], Southern Association of State Highway and Transportation Officials [SASHTO], Mid-American Association State Transportation Officials [MAASTO] and the Northeast Association of State Transportation Officials [NASTO]) and in consultation with CVSA Advisory Group comprised of no more than of nine States related to data gathering. Questions and requests for data will be coordinated through these organizations.

Questions to Guide Data Gathering with State and Industry Stakeholders and Data Experts

Note: Regarding the question on differentiating between at-limit and above-limit States based on gross vehicle weights, a category for States that do not have divisible load permit rights and require trucks to operate at no more than 80,000 pounds will be established with a second category for states that do have grandfathered, divisible load permit rights and allow permitted trucks to operate above 80,000 pounds will also be established. Representative cost information for each of those two categories will be collected from several States.  A factor will be developed to be applied to the remaining States. Information developed during the conduct of the desk scan should be helpful in identifying which States have the most reliable and current data available to complete this part of the work.

State Officials

General comment: While conducting the data gathering activities needed to complete this part of the study, States will be identified in which more detailed analysis, especially by vehicle configuration and enforcement methods that are routinely applied, may be most feasible and practical. In addition, this effort will help determine where there are opportunities for relevant vehicle-specific case studies that can be conducted.  To identify the States where detailed analysis and case studies may be most appropriate, the following information would be helpful:

  • Approaches to and methods employed in truck enforcement program activities -
    • Fixed, stationary scales (weigh-bridges);
    • Mobile enforcement using portable or semi-portable scales;
    • Roadside screening technologies used to identify trucks needing closer compliance checks and measurements.
  • Areas of specific enforcement interest -
    • Specific routes and roadway networks;
    • Specific truck configurations or types;
    • Specific commodities being hauled.
  • Impacts that a change in truck size and weight limits will have on enforcement program resources, costs and manpower needs.
  • Resources that support enforcement programs:
    • Annual budget (i.e., program costs)
    • Number of on-road officers and FTEs (specify if seasonal employment occurs)
    • Number of weighings by fixed and mobile
    • Approximate number of hours conducting inspections (fixed and mobile)
    • Quantity of fixed equipment (i.e., weigh scales)
    • Quantity of mobile equipment (e.g., portable scales, patrol cars)
    • Percentage of resources (in terms of budget, personnel, or FTEs) devoted to safety, weights & dimensions, driver/vehicle credentials.
    • If available, any information on percentage of resources allocated to specific types of truck configurations or highway networks.
  • Data used to conduct truck enforcement program activities -
    • WIM for pre-screening mainline truck traffic;
    • Ramp WIM for sorting at weigh station locations;
    • WIM as part of a mainline pre-clearance program;
    • Real-time, roving network connection WIM;
    • Digital photo identification of vehicle;
    • Automatic vehicle identification (AVI);
    • Automated counting at scale;
    • Virtual weigh stations;
    • Wireless roadside inspections technologies;
    • Others
  • Scope of enforcement program responsibilities -
    • Number of centerline miles by roadway type and jurisdiction;
    • Number of centerline miles monitored;
    • Truck vehicle miles of travel.
  • Benefits, quantified or monetized, identified with truck enforcement program.
  • Identification specific enforcement strategies seen to be very effective.
  • Alternative compliance techniques being used.
  • Methods used to measure enforcement program effectiveness.
  • Factors used to evaluate program effectiveness and monitor program performance
  • Long term trends in resources availability and program performance.
  • Recent studies or reports completed on truck enforcement program performance or program effectiveness.
  • Truck size and weight enforcement cost analysis information or data.

Representatives from CVSA Committees

Several of the previously identified data elements are relevant for data collection from State enforcement program personnel.  A number of additional data elements are also needed:

  • Program cost information associated with State enforcement agencies in conducting truck enforcement program activities.
  • Over-size and over-weight (os/ow) permit data and information.
  • Oversight responsibilities for permit compliance and enforcement.

Representatives from AASHTO SCOHT (State Regulatory Personnel)

Note: These are primarily the motor carrier safety program and regulatory personnel within State  Departments of Transportation but, in some States, are assigned to Public Safety Agencies, Departments of Motor Vehicles and Department of Revenue agencies across the country. They generally differ from State law enforcement people.

  • Availability of os/ow permit data.
  • Locations and regions or sub-regions of the State where permits are most frequently used.
  • Breakdown of permits by type (radial, annual, single trip, etc.).
  • Vehicle weights that are most frequently issued permits.
  • Enforcement personnel's access to permit information.
  • Divisible load permits associated with vehicle weight (number of permits and weight that can be permitted).
  • Availability to permitting program requirements and allowances.
  • Intensity of permit usage by type of commodity.
  • Permit compliance monitoring and enforcement activities.

Representatives from TRB Committees

Representatives of the various TRB Committees referenced previously are seen as sources of more specific information on truck enforcement practices and research and in providing insights into enforcement program activities internationally.  Consultation with Committee members will be conducted as needed.

Representatives from the Trucking Industry

Consultation with trucking industry representatives will be completed to ascertain enforcement program and technique effectiveness from their perspective.  It is not envisioned that specific data elements will be pursued from these stakeholders.

International Experts

Practices and techniques in truck size and weight enforcement have the potential of contributing to understanding the additional cost to enforcement in resources and manpower for overseeing the operation of the alternative configurations included in the 2014 CTSW Study.  The following data elements were felt to be beneficial if attained from truck size and weight personnel from other countries -

  1. Size and weight (dimension and mass) limits for commercial motor vehicles.
  2. Impacts that changes in truck size and weight regulations have had on enforcement program effectiveness.
  3. Benefits, quantified or monetized, of truck weight enforcement.
  4. Technologies used for truck weight enforcement.
  5. Enforcement strategies effectiveness.
  6. Alternative compliance techniques and their effectiveness.
  7. Measures used for enforcement effectiveness.
  8. Methods used to monitor or evaluate enforcement program activities.
  9. Recent studies or reports completed in the area of truck size and weight enforcement.

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