A roaming sensor system collects data on the condition of roads and bridge decks and identifies and maps defects, including cracks, potholes, debonding, tracking, delamination, surface ice, surface water, and rebar corrosion. Data are collected by a vehicle or a fleet of vehicles driven at normal traffic speeds. The vehicle is outfitted with sensors that collect data using acoustic surface waves, ground penetrating radar, mm wave surface radar, and/or video images. The data are transmitted to a control center for analysis and distribution.