Mobile stop-and-go laser scanning for the digital survey of unsafe crossroads

The objective of this work is the safety analysis of complex crossroads, together with the evaluation of efficiency and performance, in terms of saving time, for a mobile stop-and-go survey. We propose high accuracy digital measurements of all the elements present in order to analyze the critical factors and be able to redesignroad intersection and/or reposition of road signs.The mobile laboratory of “Geomatica”of the University of Catania (Italy) has been set up to start an innovative digital survey ofan unsafe crossroad located in Giarre (Sicily). The set up of this mission includesa Fiat Ducato, a notebook with bluetoothmodule, a Terrestrial Laser Scanner (TLS) Leica P20, and a self-leveling platform Scan&Go with relative accessories (power cable and tool to attach and fix it on the roof of the vehicle).Cutting planes of the TLSpoint cloud locatedat 1.1 and 2 meters height demonstrate that there is a condition of poor visibility of the intersection near the stop line, revealing unsafe visibility condition. The results achieved show that the use of laser scanner for safety analysis in road intersections appears to be an effective, complete and precise approach, allowing a clear improvement in the acquisition speed compared to other methods.