Ingenieur Vol 76 ingenieur 2018 October | Page 16

INGENIEUR Care must be taken, however, to establish and differentiate the pre- and post-collision damage. For example, a vehicle might have been damaged in a recent, or previous accident or it might have suffered some damage in its removal by a tow- truck or during the extraction of bodies trapped in the wreckage. 2. INSTRUMENTS FOR INVESTIGATION An accident investigator should be adequately trained and well equipped with a proper camera for taking photographs, and equipment for taking various measurements and tests. All such instruments should be examined frequently, periodically calibrated and be well maintained. During an on-the -scene investigation, photographs should be taken from various angles. Sketches and photographs of a vehicle’s damage should be made from an overhead view. These are particularly important for matching the damage between the vehicles and other objects, either photographically or diagrammatically or, a combination of both. For the investigation of the road features and conditions, PWD’s investigation team have been equipped with a number of basic testing equipment. Some of these equipment and their purposes are presented below: ● ● Sand Patch Method for Texture depth; ● ● Road Marking Reflectometer for road markings retroreflectivity; ● ● Traffic Sign Retroreflectometer for traffic signs retroreflectivity; ● ● British Pendulum Tester for skid resistance; ● ● Radar Speed Gun for spot speed studies; ● ● Ball Bank Indicator for advisory speed; and ● ● Laser Range Finder for measuring distances. 1 2 3 4 5 6 1. Ball Bank, 2. Checking retroreflectivity for road markings, 3. Checking retroreflectivity for traffic signs, 4. Conducting sand patch method, 5. Conducting skid resistance test, 6. Taking spot speed 6 14 VOL 2018 VOL 76 55 OCTOBER-DECEMBER JUNE 2013