Accident study objectives, causes, preventive measures

Objectives of crash (accident) study

• To find the number, severity, types and causes of crashes.
• To identify hazardous locations (black spots) and the accident-prone times and vehicle types.
• To study the factors (human, vehicle, road) that contribute.
• To design remedial measures (engineering, education, enforcement) and to rank them by priority and cost-benefit.
• To evaluate the effect of safety measures by before-and-after comparison.
• To support policy, planning, traffic law and insurance decisions and to give a base for safety audits.
• To compute crash rates and costs.

Causes of accidents and preventive measures

1. Road user (human) factors: over-speeding, drunk or drowsy driving, overtaking in unsafe places, ignoring signals, jaywalking, lack of experience or training, fatigue, using mobile phones. These account for about 80-90 percent of crashes.
2. Vehicle factors: brake failure, tyre burst, steering defects, overloading, defective lights, poor maintenance and lack of fitness tests.
3. Road and geometric factors: sharp curves, poor sight distance, narrow carriageways and bridges, insufficient superelevation, slippery or damaged pavement, absence of shoulders, poor intersection design.
4. Traffic control factors: missing or confusing signs, signals and markings, absent or poor lighting.
5. Environmental factors: rain, fog, snow, landslides and flooding (especially important in Nepal's hilly roads); night-time.
6. Other causes: animals on the road, poor enforcement of law and lack of emergency services.

Preventive measures — the 5 E's

• Engineering: safe geometric design, adequate sight distance, proper superelevation, signs, markings, guard rails, crash barriers, street lighting, speed humps, pedestrian crossings and bridges, black-spot treatment, road safety audit.
• Education: driver training and licensing, school programmes, public awareness campaigns and media.
• Enforcement: speed and drunk-driving checks, helmet and seat-belt laws, vehicle fitness inspection, penalty and demerit points under the Motor Vehicles and Transport Management Act 2049.
• Encouragement: reward safe drivers; promote safety culture and use of protective equipment.
• Emergency services: quick ambulance and first aid, trauma care and a good crash reporting system (IRC:53 forms A-1 and A-4).