TRB's Transportation Research Record: Journal of the Transportation Research Board, No. 2407 consists of 8 papers that examine surface wave measurements to characterize surface-breaking cracks in concrete bridge decks; a portable seismic property analyzer to assess Colorado's hanging lake tunnel liner; ultrasonic tomography to detect structural impairment in tunnel linings; and field monitoring of rebar debonding in concrete bridge decks under traffic-induced vibrations.