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

Appendix B. Summary of Data Gathered from International Experts on Truck Size and Weight Enforcement

This appendix summarizes data gathered from international experts on truck size and weight enforcement. Data were gathered through telephone/internet calls and via email exchange. Ten experts provided data; these experts included government regulators, researchers, and private consultants from Australia, Canada, France, the Netherlands, New Zealand, South Africa, and the United States.

The following sections provide summary findings organized into the following sections: (1) enforcement needs and approaches, (2) enforcement costs, (3) enforcement benefits, (4) effectiveness of enforcement, (5) application and performance of enforcement technologies, and (6) alternative approaches for achieving compliance.

Enforcement Needs and Approaches

  • Increasing allowable truck weight without changing allowable truck and axle configuration should not affect how on-road enforcement is conducted; however, changing the configuration could introduce new costs such as requiring additional enforcement staff training, educating stakeholders about regulatory changes, adjusting regulations, and updating supporting information systems. Increasing the number of axles due to increases in GVW may increase the inspection time for these trucks but likely not significantly more than current inspection times. Further, increasing truck size and weight limits may reduce the number of overweight/oversize permits issued, which has the potential to lower the number of inspections required.
  • A shortage of human resources has been identified as a current enforcement issue. This suggests that there may be an opportunity to invest in technologies that can automatically perform enforcement tasks or help enforcement officials more efficiently enforce truck size and weight limits.
  • Carriers sometimes express frustration with the varying enforcement practices across jurisdictions, indicating the potential need to pursue harmonization of these practices. Various regulatory and political differences present challenges to achieving this consistency.

Enforcement Costs

  • Many jurisdictions struggle with the high and often rising cost of enforcement, particularly those using traditional methods such as roadside inspections. Opportunities to reduce costs include reducing enforcement staff and using technologies such as WIM. Technological implementation has the potential to improve enforcement efficiency and effectiveness despite staff reductions.
  • The magnitude of enforcement costs have resulted in a South African benefit-cost analysis to consider the re-allocation of overweight enforcement funding to pavement maintenance.

Enforcement Benefits

  • There is insufficient data about enforcement effectiveness and benefits. Anecdotal evidence combined with logical reasoning suggests that increasing enforcement positively correlates with fewer size and weight violations, although experience indicates that this relationship may not be linear.
  • There is doubt that a reliable benefit-cost analysis can be achieved particularly due to difficulties in quantifying benefits. Benefits to consider include: (1) fine revenues over time; (2) cost savings in terms of actual enforcement activity; (3) safety benefits (i.e., crashes avoided) by removing overloaded vehicles from the road (not so far possible with available data); and (4) reductions in pavement/bridge damage by removing overloaded vehicles from the road (difficult to do over the lifespan of transport infrastructure with high reliability).

Effectiveness of Enforcement

  • Overall, there is uncertainty within the enforcement community about appropriate and feasible enforcement metrics; however, there is general agreement that metrics should be based on compliance rates rather than citation (or violation) rates. Implementing accreditation and auditing programs may be an effective way to measure compliance. Providing incentives (e.g., insurance discounts, increased weight) for accredited carriers can help develop a database that can accurately measure compliance. Measuring the number of inspections and violations is susceptible to providing skewed results since the whole trucking population is not necessarily represented.
  • Mobile enforcement seems to be more effective than fixed weigh scales and some jurisdictions have indicated that mobile patrolling of fixed scale by-pass routes can be effective.
  • Implementing enforcement and compliance strategies such as the chain of responsibility without providing the resources to prosecute violators does not seem to impact compliance; however, prosecuting even a small sample of violators can create enough deterrence for these programs to be effective.
  • Analyzing network-wide WIM data can shed some insight into compliance; however, limited geographic scope and the inability to identify overweight vehicles operating legally with a permit are limitations to this method.
  • Recording and collecting data from on-board load cells can provide a metric for compliance, particularly if this technology is adopted by a significant portion of the truck fleet (the adoption of this technology can be stimulated by requiring on-board cells as part of an accreditation program). This technology has been implemented in various jurisdictions including Ontario, where it provides real-time feedback to drivers and indicates whether a vehicle is compliant. An important issue to consider with on-board scales is determining who can install these sensors and who calibrates and maintains them.

Application and Performance of Enforcement Technologies

  • There is little evidence or research that quantifies the effectiveness of different enforcement technologies.
  • Due to the uncertainty about the effectiveness of different technologies and their ability to perform the multiple duties assigned to an enforcement officer, it is difficult to determine when it is appropriate to implement enforcement technologies. Technologies to assist enforcement personnel in the field (e.g., pre-screening technologies) have demonstrated their usefulness and application. For example, high-speed WIM devices can be used for pre-screening trucks and low-speed WIM devices can be used to inspect potentially overweight trucks identified by the pre-screening WIM device. Some European jurisdictions are moving towards the use of low-speed WIM for issuing citations.
  • WIM requires regular calibration, especially low-speed WIM if it is used for issuing citations. Low-speed WIM has been proven to be comparable and in some instances interchangeable with static scales. Further, low-speed WIM can sometimes provide a more accurate weight measurement than static scales since they can minimize the issues associated with springs and shifting weight that can occur when a truck stops (particularly for liquid tankers).

Alternative Approaches for Achieving Compliance

  • Anecdotal evidence suggests that the chain of responsibility, accreditation, and the Intelligent Access Program (IAP) in Australia, and virtual weigh scales and targeted enforcement in the U.S., are highly effective. Overall, incentive-based strategies that encourage self-regulation (as opposed to punitive-based strategies imposed by government regulators) appear promising and have already demonstrated perceived success.
  • If carriers want the benefits of higher vehicle weights, they should be subjected to higher safety and compliance standards.
  • Effective alternative methods for enforcement and achieving compliance include:
    • Chain of responsibility;
    • Accreditation;
    • Intelligent Access Program (IAP) developed in Australia;
    • Virtual weigh scales;
    • Targeted enforcement (i.e., analyzing a network of WIM data to identify roads most susceptible to overweight trucks and deploying mobile units to these areas)
    • Pre-screening using WIM; and
    • On-board scales

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