Highway corridor surveys are becoming more and more difficult and expensive to carry out because of the need to minimize lane closures, traffic disruptions and safety hazards posed to the surveyors as well as the public. Roadway workers and surveyors are at risk, whether in vehicles or not, when working in the traffic corridor if they can’t move with the flow of traffic. Safety for the traveling public is also a major problem when lanes are closed, or blocked by slow moving vehicles. Working on the edge of the corridor and having to enter and exit traffic flow can also be dangerous tothe highway worker as well. Costs for the placement of safety trucks and pylons to protect the survey crew can in some instances be greater than the cost of the survey work itself. In order to mitigate these problems, a survey data acquisition tool is needed that can collect detailed topographic and infrastructure information without requiring traffic management, lane closures or even a disruption in traffic flow. Terrapoint (www.terrapoint.com) has developed a novel kinematic terrestrial based laser scanning system that can be deployed on a passenger vehicle or small watercraft. LIDAR (Light Detection And Ranging), digital imagery and digital video are collected from the survey platform while it is moving at speeds up to 70 mph. The system is georeferenced using a high accuracy GPS/INS system. Terrapoint’s mobile color LIDAR scanner has successfully been used as a stealth survey tool on existing highway corridors in California, Washington, Ontario, British Columbia, and Texas. It has also proven to be accurate enough to scan airport runway surfaces in order to predict areas where water will pool, an application that could be used in a similar manner on road surfaces. Traveling with the traffic flow and not requiring an escort, the system scans a 360 degree swath that includes the pavement surface as wellas objects to the sides and above the survey vehicle.
Samenvatting