Road safety

Road crashes kill and injure very large numbers of people every year, and most victims are pedestrians, cyclists and riders of two-wheelers. Engineers cannot prevent every human error, but they can design roads that make errors less likely and less deadly. That is the core of the safe system approach: people make mistakes, the human body has a limited tolerance to impact, and the road system should be forgiving.

Speed is the master variable. Impact energy rises with the square of speed, so modest reductions in speed save many lives. Engineering tools include speed management through design (lane width, curvature, traffic calming, roundabouts), separation of road users (medians, footpaths, cycle tracks, pedestrian crossings and refuges), forgiving roadsides (clear zones, frangible poles, crash barriers and crash cushions), clear signs and markings, good lighting and skid-resistant surfaces. Black spot treatment identifies locations with repeated crashes and fixes the cause.

Road safety audits review designs at each stage, from feasibility to pre-opening, with independent auditors who look at the road from every user's viewpoint. Crash data, recorded consistently, is the evidence base: types, times, locations and contributing factors. Combined with enforcement, vehicle safety and emergency care, engineering measures can cut fatalities substantially. Indian guidance covers audits, barriers, signs, markings and traffic calming.