Recently there has been a lot of discussion in the media and elsewhere about how we can reduce the road toll and how speed plays a part in this. While the impact of speed on the road toll is well known – the faster you go the bigger the mess – the appropriateness of the speed limit doesn’t get much discussion.
A lot of people seem to think that a lot of thought has gone into the setting of speed limits, when in reality most of our speed limits are purely historical with little sound engineering behind them.
- In 1948, it was increased to a maximum of 50mph.
- With cars becoming more powerful, the open road speed limit was increased again in 1962 to 55mph and 60mph in 1969.
- While the open road speed limit was dropped back to 50mph (80kph) in 1973, as a fuel saving measure, this was raised again in 1985 to 100kph – partly to reflect prevailing vehicle speeds.
What this shows is that the historical thinking around speed limits had very little to do with safety, but rather about vehicle capability. If we were to continue this thinking today, the open road speed limit would be set at 130kph+ which is what the majority of vehicles on our roads can do – but for which our road network clearly is not designed for.
Over the last 10 – 15 years, as a more considered approach has gone into reducing our road toll, the discussion has shifted to setting SAFE and APPROPRIATE speeds. Just because a vehicle can be driven at a certain speed, it doesn’t mean it’s safe – the appropriate speed will consider the movement and place function of the road, its design and surrounding infrastructure. This approach, part of the Safe System philosophy, also recognises that drivers will make mistakes but that the mistake shouldn’t result in a death or serious injury.
As we apply this more rounded approach, and look at the engineering and design of our roading network and its usage, its quite clear that the 100kph limit is not appropriate. Its simply a hangover from the past which is contributing to our horrendous road toll. That is not to say we can’t have 100kph or higher roads, look at the Waikato expressway, but recognise it was designed for this speed – appropriate lane and carriageway widths, median and side barriers with roadside infrastructure, such as light poles, behind them. Compare this photo (right) of the Waikato expressway with other parts of the open road – notice the difference?
The simple fact is that the majority of our network was not designed for the 100kph and we are now simply trying to correct this relic of history.
So next time you get a ticket for doing 110kph in a 100kph zone, don’t complain to the officer about how your speed was ‘safe’, thank them for letting you off lightly, as the safe and appropriate speed is, in reality, likely to be 70 or 80kph. After all, they are also just trying to keep you safe.
Matthew Noon
Associate Director, Safe System