Systems WIM
Weigh-in-Motion (WIM)
Weight Enforcement
The Transportation Research Board states that, "enforcement is a critical element of any plan for controlling vehicle weights. Without effective enforcement, including the certainty of penalties and sanctions sufficient to deter violations, weight limit laws become meaningless." It is well known and accepted that heavy trucks cause a significant proportion of damage to roads and bridges. One way to minimize the impact of heavy trucks on our nation's roadways is through intensive weight enforcement.
Traditionally, weigh stations with static scales have been used to weigh the majority of commercial carriers on the road. Where truck volumes are low, static scales are an effective method of weighing trucks. However, many weigh stations today cannot accommodate the increasingly high volumes of truck traffic, without causing unnecessary truck traffic backups, delays and allowing many carriers to bypass without ever being weighed. As well, permanent weighing sites cannot reach trucks that choose to travel on bypass routes to avoid inspection.
To address the problem of inefficient and time consuming weighing at weigh stations, IRD provides WIM Mainline and Ramp Sorting Systems, to preweigh and presort trucks prior to weigh stations. Only those trucks potentially in violation of weight regulations or other operating requirements are directed to report for further inspection. To address the problem of overloaded trucks on bypass routes, IRD provides its Virtual Weigh Station and its Mobile Weight Enforcement and Truck Inspection System.
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How WIM Works
IRD's Weigh-in-Motion systems vary widely in functionality and level of complexity, using Piezoelectric and Lineas® Quartz WIM sensors, Slow Speed WIM scales, PAT Bending Plate WIM scales or Single Load Cell WIM scales. At weigh stations, WIM systems provide preliminary dynamic weight readings which can be used to preclear and automatically sort vehicles. The truck traffic over the static scales can be minimized to target only those vehicles which are suspected of being overweight. In some cases, trucks can be precleared through a weigh station, without even slowing down along the mainline. On bypass and secondary roads, IRD's Virtual Weigh Station can be used to identify suspected overloaded trucks and offenders. In other cases portable WIM equipment, such as the DAW 300PC, can be used for spot checks on back roads and alternative routes that are not protected with weigh stations. If there is a possibility of a truck being overweight based on portable WIM results, it is directed to a nearby static scale for more accurate weighing.
IRD integrates WIM technology with a combination of other technologies, including AVI systems, freeze frame cameras, fiber optic signs (fixed, changeable and fully variable), static scales, databases (varying from local to nationwide), lane control signals and other weigh station components. IRD develops and modifies software using its standardized modules that are customized to meet the particular needs of each site. By using a majority of off-the-shelf hardware and components, service and maintenance costs are minimized.
- New WIM Applications (pdf - 2.3 mb)
(PDF files require Adobe Reader)
