RFID tags curb street repair time

In many cities like Dayton, Ohio, when utility companies dig up streets to install sewer pipes or fiber optic lines, they are responsible for properly filling in any holes or trenches. If the street cut isn’t repaired properly, that area could sink or turn into a pothole – a problem for the city and a potential hazard for motorists.

Officials in Dayton realized that it sometimes took the city’s only utility inspector weeks to identify which company was responsible for a defective restoration and get it fixed.

But in the last year, the city has come up with a nifty wireless fix for the problem. Dayton now requires utilities to embed a RFID (radio frequency identification) tag in the roadway. The tag resembles a 4- to 5-inch pixie stick coated in protective plastic and is loaded with data germane to each street cut. Using a handheld RFID reader, an inspector can find out instantly whether a gas, electric, sewer, water or telecommunications company was responsible for a cut, vastly reducing the time to investigate road complaints and fix problems.

“I’m sure our citizens and businesses have no idea there are RFID tags beneath some of Dayton’s streets, but the data collected should help the city save money, time and resources over the long run,” said city manager Tim Riordan in an email.

Dayton may be the first U.S. municipality to use RFID technology in street utility cuts, project officials said. The project has also been named as a finalist for the 2014 RFID Journal Awards.  

Investigating complaints

Back in July 2011, city officials asked engineer-in-training Andrew Marks to research how to make the utility inspector’s job more efficient and enhance citizen safety.

According to Marks, an experienced inspector can usually determine which company is responsible based on, for example, a nearby sewer manhole cover, a gas or water valve box or other marking. However, for most complaints, the inspector has to search a decade-old Microsoft Access database - with records of permits dating back to the 1990s - using a nearby street address. On occasion, he may also have to sift through older paper records, but even that could be a dead end. The last resort is contacting the non-profit Ohio Utility Protection Services, which comes out after 48 hours to mark all underground utilities in an area.

Initially, Marks consulted with the city’s local tech hub known as Tech Town about possibly using RFID technology to make the identification process much quicker and simpler. Those discussions led Marks to local systems integrator CDO Technologies, which eventually helped design and implement the RFID solution. The idea was that each road cut would be identified with an RFID tag containing a two-digit code corresponding to a registered utility, a five-digit permit number and the year the street cut was restored or repaired. The permit number links the information to a larger city database containing more comprehensive data about the project.

Testing RFID feasibility

But first, the team had to determine whether the technology was even feasible. Asphalt temperature, road compaction, pressure from cars driving over an area and even moisture can all affect how an RFID tag works. For instance, the tag would need to withstand the 350-degree heat of the asphalt used to fill a hole.

Robert Zielinski, director of commercial marketing for CDO Technologies, said team members tested a dozen or so different RFID tags before they settled on one that was durable and cost-effective. Not an easy task since “there are hundreds of different flavors of tags,” he said.

After some lab testing, they conducted a field test by installing a tag under asphalt. Each time they came back to read the data - after a week and then after a month or two - it worked.

CDO Technologies also configured its software platform - High Value Asset Tracker or HVAT -  for Dayton’s office and field applications.

The office application, which sits on top of an SQL database, collects utility permit data and logs relevant reference identification data onto a tag using the Alien Technology 9650 desktop RFID reader. The field application and handheld reader allows the city inspector to find and decode embedded tags.

Banking time savings

The city officially implemented the new system on April 2013. When utility companies now apply for a roadwork permit, they are also issued the appropriate number of configured RFID tags for that specific project. All that contractors have to do is place the tags two inches below the surface in the center of a road cut or at 50-foot intervals for longer trenches. CDO’s Zielinski said it was important to make the process as simple as possible for contractors.

So when the inspector is called out to investigate a needed repair, instead of looking at his database or nearby road markings to find out the responsible utility, he simply scans the cut with a Motorola handheld RFID reader. “And within seconds he’s going to be on the water company or the gas company and say, ‘Hey, you’ve got a bad cut,’ ” Marks said.

In 2013, the city issued about 2,500 tags to contractors at a cost of about $2 apiece, which is built into a permit price. It plans to distribute another 2,500 tags this year. Marks said compliance with the project has been nearly 100 percent.

While tens of thousands of street cuts still don’t contain an RFID -- and will need to be investigated the old-fashioned way -- Marks said the city will see a significant time savings when the first cut embedded with an RFID is investigated. He said it will take a few years, but the city projects savings equivalent to about $60,000 in manpower annually once all cuts contain RFIDs.

Total project cost so far is about $50,000, which includes CDO Technologies consultation, software development, two Motorola handheld readers, the Alien Technology reader, and 1,250 initial RFID tags. The city also purchased another 10,000 tags for $20,000, which should last another three years, Marks said.

He added that Dayton is investigating additional uses of RFID in other aspects of road construction. In the meantime, it recently decided to use RFID tags during the winter months when “cold patches” are used to repair roads. Cold patches are temporary fixes that tend to degrade or sink more quickly, causing road hazards. Marks said city officials initially didn’t want to waste tags on temporary fixes, but they realized safety was a year-round issue.

Zielinski said CDO Technologies has fielded inquiries from other interested cities, but the system has not yet been deployed elsewhere.