We would like to share these insights:
1. Overview
The problem with driving 235km/h in a 120 zone is not necessarily the speed itself. In his work, Traffic Safety, researcher Leonard Evans provides data showing that when a human body experiences a Delta-V (change in velocity) of 105km/h or more in a crash, fatality rates are 100%. A crash generating a Delta-V of 105 km/h could easily be occasioned by hitting a bridge pillar or other solid object at 120km/h, or an oncoming truck at an even slower speed. In other words, your death risk in a crash at 120 is not necessarily much lower than at 235. Bear in mind that cars are only crash-tested at 64km/h!
2. Speed for conditions
Having dealt with the issue of fatality risk, there remain three problems with travelling at such a high speed:
• You are sharing the roads with traffic whose speed may differ vastly from yours – the slightest error by another driver leaves you with no safety margin at all.
• Your braking distance under ideal conditions at 235km/h may exceed 300 metres. You are travelling at nearly 66 metres per second, meaning that your reaction time under ideal conditions is equivalent to nearly a city block, and possibly much longer if you are fatigued, distracted or have consumed alcohol.
• You may not physically have enough forward visibility to detect hazards and respond to them timeously at that speed. I have video footage proving that there there is less than three seconds of visibility at 120km/h at many blind rises and corners. That is cut in half at 235km/h, and there’s no way a mere 1.5 seconds at that speed will be adequate for collision avoidance. Your reaction time alone may be a second or more! Consider other hazards too: another car having a tyre burst and swerving into your lane, a load falling off a truck or a pedestrian running across the road.
Granted, pedestrians are not supposed to be on freeways, but they nonetheless are, and must be dealt with on that basis.
Leaving aside the legalities, from a safety point of view, I would concede that a typical freeway could sustain 140km/h safely. Perhaps even 160km/h under light traffic conditions. But I can envisage no circumstances under which 235km/h could be considered a safe speed to travel in South Africa.
Maybe in Germany where other drivers are disciplined, cars are roadworthy, roads are well-maintained and other sundry aspects like pedestrian control and load management on heavy vehicles are properly enforced. But definitely not in South Africa.
3. Government safety campaign
It is the responsibility of government to implement and promote national road safety campaigns. When an MEC, a highly-placed member of government, notches up the highest recorded speed of the festive season, it signals that there is a gap between what government says about road safety and what its individual members believe and do about it.
It is optimistic to hope that citizens will drive with care and respect for the safety of other road users when our elected officials – and often our law enforcers – don’t set the correct example.
For further information contact:
Rob Handfield – Jones
rob@driving.co.za
www.driving.co.za