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This Technical Summary pertains to LRRB-produced Report 2013-27, “Improved Approach to Enforcement of Road Weight Restrictions,” published November 2013.

This Technical Summary pertains to report 2021-27, Refining Inductive Loop Signature Technology for Statewide Vehicle Classification Counts.

This Technical Summary pertains to Report 2015-17, “Commercial Vehicle Enforcement Innovation,” published April 2015.

This Technical Summary pertains to Report 2015-18, “Implementation of Traffic Data Quality Verification for WIM Sites,” published May 2015.

This research project utilized statistical inference and comparison techniques to compare the performance of different Weigh-in-Motion (WIM) sensors. First; we analyzed test-vehicle data to perform an accuracy check of the results reported by the sensor-vendor Intercomp. The results reported by Intercomp mostly matched with our own analysis; but the data were found to be insufficient to reach any conclusions about the accuracy of the sensor under different temperature and speed conditions. Second; based on the limited data from the Intercomp and IRD sensor systems; we performed tests of self-consistency and comparisons of measurements to inform the selection of a superior system. Intercomp sensor data were found to be not self-consistent but IRD data were. Given the different measurements provided by the two sensors; without additional data; we were not able to reach a conclusion regarding the relative accuracy or the duration of consistent observations before needing recalibration. Initial comparisons indicated potential problems with the Intercomp sensor. We then suggested alternate approaches that MNDOT could use to determine whether recalibration was required. Finally; we analyzed ten-month data from the IRD WIM system and four-month data from the Kistler WIM system to evaluate relative sensor accuracy. While both systems were found to be self-consistent within the data time frame; the Kistler system generated more errors than the IRD system. Conclusions regarding relative accuracy could not be reached without additional data. We identified the sorts of measurements that would need to be monitored for recalibration and the methodology needed for estimating future recalibration time.

This report presents tabulations of types of vehicles and weights of trucks found at various locations on State-Trunk Highways during the years 1973, 1974 and 1975. Data processing errors found on the 1973 and 1974 data delayed publishing the 1974 report and invalidated much of the previously published 1973 report; hence, a three year report is required. This report is also being published while the Department is in the midst of updating both the vehicle type and truck weight programs to make them more user oriented and economical. Therefore, this report reflects some of the changes being made (elimination of truck interview and dimensions data, additional graphs), while future reports, to be prepared biennially, are expected to be even more usable and comprehensive.

This report contains 1984-1985 data collected at three permanent continuously operating weighing-in-motion (WIM) stations. A map showing the locations of these stations is on page 4.

In 1980, Minnesota created a new enforcement technique for controlling overweights in trucks. This new law allowed Bills of Lading, weight tickets, and other documents that indicate the weight, of a truck to be used as evidence in a civil court proceeding to establish overweight violations. Under many circumstances it. is no longer necessary for the State patrol to catch an overweight truck on the road. A demand for the payment of penalties can be sent out in the mail and if not paid a law suit initiated under civil proceedings. In spite of the fact that this legislation was supporter) by the trucking industry, this new technique bas created some controversy. This report outlines the issues and problems associated with this law and is intended to provide background material for individuals interested in weight enforcement.

The Third National Conference on Weigh-in-Motion (WIM) was held to share information and experience on this rapidly advancing technology. The first such conference was held in Denver, Colorado in 1983 and explored the technology in its infancy. The Conference looked ahead to experimentation, testing, and demonstrating the capabilities of WIM. A second conference was held in Atlanta, Georgia in 1985. WIM use and interest had grown from a handful of states to a majority of states and the conference looked ahead to the use of WIM data for enforcement, design, and pavement management. The third national conference on WIM was attended by representatives from all 50 states and eight foreign countries. Presentations and demonstrations clearly revealed wide spread acceptance and use of WIM for both enforcement of vehicle weight laws, pavement design, and management.

The Minnesota Department of Transportation has operated permanent continuous weigh-in-motion stations since 1981. At present, 16 sites are collecting volume and weight data by vehicle type for use in transportation planning and design. Questions that can be answered from an analysis of this data can provide useful information. For example, gross weight trends of big trucks in Minnesota have been speculated on with great interest. Are trucks on the highways getting heavier? With a number of years of accumulated data from the first WIM sites and several years from succeeding locations available, we have the means to answer this question.