What is the secret to making roads more durable and ultimately cost less to build and maintain? The answer might be inside a host of sensors embedded in a pavement test track located in Minnesota.

The MnDOT (Minnesota Dept. of Transportation), www.dot.state.mn.us, Duluth, Minn., is researching various types of materials and pavement designs. This research is being done inside its MnROAD facility, and the objective is to make roads last longer, perform better, cost less to build and maintain, and have minimal impact on the environment.

One of the methods to document performance is to embed sensors—sometimes hundreds of sensors—in the different test cells in the road. Data is then collected from the sensors as the test vehicle is driven over the sensor. The precise location of the sensor becomes key in order to properly analyze the data for both concrete and asphalt-surfaced roadways.

The challenge is that in order to obtain accurate results the test vehicles need to be driven directly over the sensors. In the past, GPS survey equipment, visible markers, and video surveillance had been used to determine the location of the sensors, but proved unsuccessful.

As such, the MnDOT decided to take a different approach—RFID (radio frequency identification). Working with Portable Technology Solutions, www.tracerplus.com, Calverton, N.Y., the developers of TracerPlus and ClearStream RFID software, and EMKAT, www.emkat.com, Plymouth, Minn., the MnDOT began using RFID tags in the pavement test track.

The team installed the RFID tags roughly 6 inches below the concrete within 1-2 inches of the sensors. Once embedded, a Motorola device with TracerPlus mobile RFID software allowed the team to locate each sensor and mark the path with 90% accuracy.

With the technology, the team was able to reduce costs and increase efficiency of the testing performed by ensuring the test vehicles are driven accurately above the sensors.

Sensors and RFID are increasingly proving to be worthwhile investments in the construction industry, as the price of the tags come down and the use cases become more evident. This is just one example of how the technology can provide value in construction.