Infrasense recently completed deterioration mapping for two mainline bridge decks and six adjacent ramp decks, representing over 100,000 square feet. The Silliman Evans Bridges carry Interstate 24 over the Cumberland River, just north of the I-24/I-40 interchange. The deterioration mapping was performed using vehicle-mounted high-speed ground penetrating radar (GPR) to scan each bridge deck without requiring lane closures and with no disruption to traffic flow, and data collection was completed in a single night. The GPR data was used to produce concrete deterioration maps, as well as rebar depth and asphalt overlay contour maps. These results will be used to plan future rehabilitation efforts.