A 2014, Department of Transportation report finds that to maintain the condition of U.S. highways and bridges at 2010 levels through the year 2030, between $65.3 billion and $86.3 billion per year would be required. A suburb in the greater St. Louis area has recently been searching for ways to investigate their roadways in an objective manner that will assist in repair or replace decisions as well as prioritizing the order of repair or replace decisions. The combination streets, asphalt over concrete, were giving them the most trouble due to the condition of the asphalt not always being representative of the concrete below. Initially, the city engineers believed that asphalt was in poor condition and the concrete beneath would be in relatively good shape, but after milling a few streets it was determined that the concrete was also distressed and the entire roadway would have to be replaced.
Milling can be loud, time consuming, cause lane closures and detours, and be costly. Remote sensing techniques such as Infrared Energy Pattern Analysis (IR-EPA) and Ground Penetrating Radar (GPR)provide objective data that doesn't cause inconveniences by preventing lane closures. The data is also collected in a timely and cost-effective manner. These tools can also determine if there are erosion voids or sinkholes beneath the roadway, delaminations (horizontal cracking caused by rusting rebar), water or sewer leaks that may saturate the supporting soils., separation of asphalt from concrete, as well as pavement thickness for contractor quality inspection. For a complete solution IR-EPA and GPR can be combined with lasers, accelerometers, and GPS to measure how smooth the roadway is and tie all of the results into a single GIS database for analysis and prioritization.