How to make your highways talk to you (so you can save money on repairs)

Wed, 2016-02-03 06:00 -- Doug Peeples

The first order of business in a smart city (or county or province or country) is to get the data needed to understand conditions. And to get it in real time, not days or weeks or months later, when it's often too late to help.

Here's a novel way to collect highway data that's being developed by the University of Massachusetts. And a clever way to use that data to impose seasonal weight restrictions that could ultimately save millions in repair costs by preventing the damage in the first place. -- Jesse Berst

Road maintenance for cities, counties and states is expensive enough as it is. But for northern regions that typically experience long spells of below freezing weather, those expenses can be magnified greatly as  smaller local roads begin to thaw during spring and the ground beneath them becomes waterlogged and soft.

When spring thaws come, the upper layer of ground close to the surface and the layer well below it warm up, trapping a layer of frozen ground in between. The problem, a research team from the University of Massachusetts believes, is the frozen layer traps water near the surface that otherwise would drain into the ground. And when heavily loaded trucks roll over those roads that no longer have a solid base, they can do a lot of damage, according to researcher Heather Miller.

The damage from heavy truck traffic during spring thaws can be as much as they would otherwise cause over a year's time, according to a rough estimate from Miller and her team. And yes, it does get expensive. The International City/County Management Association surveyed its members and found that average expenses per lane mile of road were $3,867 for road maintenance -- under normal circumstances.

The problem…
Northern governments responsible for maintaining those roads use sensors embedded in the ground to help them determine when to impose -- and when to lift -- seasonal load restrictions (SLR). But those sensors need to be read manually to collect temperature data, which is typically done only every week or two. As Miller pointed out, the decision to impose an SLR can be costly for the trucking industry which is required to make more trips with lighter loads and the people who depend on them. That, and if the restriction is imposed for too short a time, the roads are likely to sustain more damage.

And a promising solution…
In a pilot study now underway, Miller and others at the university deployed transmitters for the sensors to allow the temperature data to be sent by satellite. The transmitter-sensor combination allows temperature changes to be monitored twice a day, and additional information such as air temperature also is fed into the monitoring system.

The expectation is that once cost (data collection via satellite is expensive) and connectivity issues are resolved, the technology will be made available to other northern states. Miller said it could also be used to track rising sea levels and provide flood information to local governments in coastal areas.

Doug Peeples is a Portland, Oregon-based writer specializing in technology and energy. Follow @smartccouncil on Twitter.