Better timing for seasonal load restrictions with connected sensors

By Bill Holloway

Researchers at the University of Massachusetts, Dartmouth, have developed a new way to monitor the underground sensors that help states determine when seasonal load restrictions (SLRs) should begin and end. States impose SLRs during times when roads are particularly vulnerable to damage by heavy trucks, most commonly during the spring thaw, when heavy trucks can do a year’s worth of damage in a few days.

Many states use in-ground sensors to monitor soil conditions but these have to be checked manually by workers who need to drive to each sensor site and connect the device to a data logger. The labor intensive process, and the fact that many of the sensors are located in remote areas, has meant that the sensors are checked only every week or two. The lack of regular data about the freeze-thaw cycle affecting roads has meant that setting SLRs has been somewhat imprecise. If SLRs are put in place too early, trucks will have to make more trips to carry the same amount of freight—adding to business costs, traffic congestion, and air emissions. On the other hand, if SLRs are enacted too late, then the heavy trucks could do serious damage to the roadway.

The solution developed by the researchers involves connecting transmitters to the in-ground sensors to enable them to regularly transmit their data to an online platform and decision-making tool that also receives air temperature data from Weather Underground. Using this tool, states can better predict the best times to impose and lift SLRs.

The project is currently in its pilot study phase and researchers are working out how to lower operating costs for the system and adapt it for other purposes, such as monitoring water levels in coastal and flood prone areas.

Find more on this topic in Ben Miller’s article on the subject in FutureStructure.

Bill Holloway is a Transportation Policy Analyst at SSTI.