Will speed limiters in cars truly save lives?
Researcher: "We don't know the answer to that yet"
Research has uncovered several disadvantages of speed limiters.
Published
After 14 people lost their driver's licenses in a district in south-eastern Norway on the night of Sunday, October 27, the Norwegian Council for Road Safety advocated for a speed limiter in new cars, according to Norwegian Broadcasting Corporation NRK.
Enforcing speed limiters would save many lives, the Norwegian Council for Road Safety believes.
But do we really know that?
An open question about whether speed limiters save lives
Theoretically, fewer people would be severely injured or killed if all drivers kept to the speed limit.
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This is shown by research from the Institute of Transport Economics (TØI). It could have led to 15-20 per cent fewer serious accidents.
But theory is not the same as practice.
Whether enforcing speed limiters actually save lives is therefore an open question, according to Alena Høye, a researcher at TØI.
Several drawbacks of enforcing speed limiters
When we talk about speed limiters, it is often the intelligent variant that is most relevant.
These are systems that adapt to the speed limit.
"No country has yet introduced enforcing intelligent speed adaptation for all cars. So we don't know the answer to that yet," says Høye.
Together with colleague Rune Elvik, she has reviewed Norwegian and international research on the topic in TØI's traffic safety handbook (link in Norwegian).
They found several disadvantages.
Harder or impossible to drive faster
Research on enforcing speed limiters has uncovered these negative aspects:
- It is unpopular.
- Those who want to drive fast may stick to older cars, buy cars from abroad, or find other ways to bypass the limiter.
- Some drivers rely too much on the system and drive faster than is safe.
- The system may display an incorrect speed limit if it fails to detect a sign.
- The gap between cars decreases when people use intelligent speed limiters.
Therefore, Høye believes it is difficult to estimate how many serious accidents such a speed limiter mightprevent.
"With all the potential disadvantages, I think it's a bit misleading to say that theoretically, so and so many people would not have been killed or seriously injured if everyone had driven with an enforcing speed limiter," says Høye.
Does not target reckless drivers
The question is whom such a measure would affect.
The most realistic alternative might be a speed limiter that makes it harder to drive over the speed limit. For instance, requiring a firm press on the accelerator to exceed the limit.
Research on this type of intelligent speed adaptation shows that the speed decreases.
Cars drive slower, but only on average.
For reckless drivers, it does not have an impact.
"It has a very good effect among drivers who are positive to begin with, but less among those who don't really want it," says Høye.
The display provides a lot of information to process
And among some regular drivers, speed actually increased.
Høye believes this may be due to the display in the car detracting from drivers' judgment.
There is a lot of information to process.
And not everyone has given much thought to where the information displayed in the car comes from.
Confiscating cars for speeding
So what alternatives are there to enforcing speed limiter?
More speed checks could reduce speed among regular drivers, according to the TØI researcher.
But tougher measures are needed to stop reckless drivers.
Losing a driver's license does not seem to be enough.
An effective alternative could be to confiscate the car.
"Studies from the USA that have looked at this conclude it's quite effective, especially among those driving expensive cars," says Høie.
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Translated by Alette Bjordal Gjellesvik
Read the Norwegian version of this article on forskning.no
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