Speed crackdown creates passing danger
Today’s road policing may be contributing to more accidents The reality of openroad motoring now ensures even more danger during overtaking.
The police obsession with vehicle speeds may actually be contributing to the rising road crash rate by making overtaking more dangerous. In the past, many traffic officers would turn a blind eye to a driver briefly exceeding the speed limit while overtaking a slower vehicle, even though this may not have been a reflection of official policy at the time. There was a belief that a little speed was less dangerous than spending longer than necessary on the wrong side of the road.
Now the reverse case holds sway, which, along with strict policing of speed, has resulted in many drivers overtaking without exceeding the open road 100km/ h speed limit.
In the meantime car acceleration, braking, tyre grip and electronic safety systems have improved considerably.
A standard truck and trailer is 20 metres long. At 80km/h a following driver should leave a two-second gap of 44 metres. It takes at least 20 metres ahead of the truck to pull back into the lane, so there’s 84 metres in total to overtake. At a steady 100km/h that will take 15 seconds, excluding the time it takes to accelerate from 80km/h to 100km/h, which will vary considerably with different vehicles.
At 120km/h it will take just 7.5 seconds, although the period spent accelerating will obviously be slightly longer. Not much, though, with many modern cars and even SUVs capable of accelerating from 80km/h to 120km/h in around five seconds. Powerful motorcycles manage it in less than two seconds.
It will be argued that the higher the speed the greater the wreckage in a crash. However, assuming the car coming the other way is doing 100km/h there’s unlikely to be a significant difference in the damage between closing speeds of 200km/h and 220km/h.
On the other hand, the risk has halved, as the faster overtaker has spent 7.5 seconds less on the wrong side of the road. Put another way, at 100km/h he will have been on the wrong side for an additional 208.5 metres.
Of course, the reality of open-road motoring now ensures even more danger during overtaking. If the 80km/h vehicle being overtaken is a car rather than a heavy truck, it’s likely to speed up on any passing lane or straight section of road. Studies have demonstrated that it is a natural human reaction to speed up when the road is wider. An example is how different 100km/h feels on a narrow back road than on an empty multi-lane motorway.
The outcome is that the overtaking manouevre can take considerably longer, with it far from uncommon for two cars to reach the end of a passing lane side by side at 100km/h.
It can’t be a coincidence that a number of head-on smashes occur near the ends of passing lanes.
Also in reality, the heavy truck is more likely to be travelling at 95km/h, which means it will take a whole minute – or 1.7km of road – for a car doing 100km/h to get past. How often do you sit back and watch one car use up an entire passing lane to overtake a truck, leaving a queue of impatient motorists behind?
And this introduces yet another hazard. Any cars following the slow overtaker can be hung out to dry beside the truck as the first car ducks in front right at the end of the passing lane. Truck drivers often have to take to the hard shoulder to give cars space to get by, or hit the brakes and drop back behind.
Many — probably most — of these drivers could quite safely remain in control of their vehicles for a brief burst at 120km/h, which would enable them to overtake much more safely.
All that’s preventing them is fear of a speeding ticket.