Abstract: A mobile system for measuring characteristics of traffic-bearing surfaces has laser cameras mounted on a vehicle for measuring the distance to the surface as the vehicle travels along it. A rotating laser at a known, fixed elevation generates a laser plane over the surface while a second oscillating or rotating laser generates a substantially vertical laser plane in the direction of measurement of the surface. The vehicle carries a pair of sensors for detecting the incidence of the laser planes thereon. The sensors generate signals which represent the exact vertical and lateral position of the vehicle with reference to the fixed laser planes at any point on the surface. These signals are used to obtain values representative of the vertical elevation of the surface compensated for deviations in the vertical position of the vehicle during the measurement, and to record and control the measuring path of the vehicle.

Abstract: A method and apparatus are provided for measuring the load bearing capacity of a surface by continuously transporting a known load along the surface and measuring the resulting deformation thereof. In one embodiment a contactless laser transducer is mounted directly in front of and behind a loaded wheel for measuring the elevation of the surface before and after the load. A computer determines the difference between the measured elevations which is indicative of the load bearing capacity of the surface. Conventional recording, display, and storage equipment are provided for recording, displaying, and storing the elevation values and the corresponding differences. The load velocity and longitudinal position may also be determined and stored with the corresponding elevation and difference values.