Intelligent Speed Adaptation (ISA)
A car that won't break the speed limit?
Whether you consider it a gift from the gods or the exact opposite, technology capable of preventing a car from breaking the speed limit is just around the corner. The technology is known as Intelligent Speed Adaptation – ISA for short.
How would ISA work?
All that is needed already exists.
Satnavs can already place you on a map, and know the name of the road you are on, and it's easy for them to be programmed to know the speed limit.
Once that's been achieved it's a fairly simple matter to link the system to the throttle so that a car won't go beyond the speed limit, and one that is exceeding the speed limit is slowed until within the limit and prevented from going faster.
What could ISA do?
There are three simple options for ISA.
- Advisory - a very simple device that tells you the speed limit, and which bleeps or gives some other kind of warning when you go over the limit
- Controlling - hard wired into the car so that it was impossible to break the limit
- Discretionary - a halfway house, where the driver could switch between 'controlling' and 'advisory' or even switch the system off altogether
Would fitting be mandatory?
Not at the moment, but if all worked well it would be expected to be at some time in the fairly distant future.
It would be most unlikely for the government to require existing cars to be fitted retrospectively though and that is something that the AA would most likely oppose.
More likely is that some businesses will fit it to their fleet cars or vans, possibly in advisory form. Then car makers might start offering 'advisory' or 'discretionary' systems as optional extras.
If popular/effective on an optional basis then, as was the case with air bags, ABS brakes and stability control, manufacturers might then start fitting ISA as standard, initially on more expensive models.
It is unlikely that car makers would fit 'controlling' systems unless there were legislation requiring them to do so.
The question then is whether, and when government would make such a decision. It seems unlikely it would be done in a hurry, and it's hard to see that it could be a British decision alone as vehicle standards are regulated at the EU level. However, most new car technologies that prove effective in road safety terms have eventually become compulsory.
What could go wrong?
One possibility is that an ISA system could apply the wrong speed limit, cutting motorway traffic to 30mph because of a close minor road for example, or allowing a car on the minor road to do motorway speeds.
Opponents will say that the merest chance of this should be enough to prevent the system ever taking to the roads.
Supporters on the other hand would argue that the motorway driver should be able to notice the application of the lower limit within milliseconds and turn the system off, while traffic on the minor road would not be forced to accelerate, and the driver would have to make a conscious decision to do so.
As ISA would only ever stop you exceeding, or warn you of the maximum speed limit, drivers will have to continue watch their speed ensuring that it is appropriate for the local situation.
How could ISA affect driving?
ISA could make overtaking difficult, and prevent accelerating out of a misjudged situation in some cases. But it can be argued that drivers would just have to remember to switch the system off when overtaking.
Similarly there could be problems if the speed limit changed downwards during an overtaking manoeuvre. Again the value of the off-switch can be argued, while some would argue that no driver should overtake under those circumstances anyway.
It has been suggested too that ISA would lead to 'bunches' of cars, all travelling at the same speed, and that many drivers would depress their accelerator to the floor and drive just as fast as the car let them.
While most who have taken part in experiments with the system have not done this, it does have to remain a possibility.
But if it is a problem it would soon come to light as ISA becomes more widely available as an option.
What do drivers think?
Much depends on what sort of system is being debated. In an AA Populus poll of 17,481 respondents, 43% thought the compulsory introduction of 'controlling' ISA would be acceptable compared to 49% who didn't. So drivers don't want it forced on them.
But another survey showed that 61 per cent of drivers said that if their car was fitted with a device that when switched on would stop them exceeding the speed limit, then they would use it. This seems to suggest greater support for discretionary ISA. The AA also gets calls from members wanting to know how they can get hold of this system.
AA view
On balance a voluntary, discretionary or advisory system probably has safety and practical benefits as it can remind us of speed limits and help prevent accidents and penalty points.
However, a mandatory system would be a step too far as the human element of judgement must always govern our safe driving. Perhaps the best answer is to allow time, and the market, to take its course as has happened with other in-car systems. But ultimately the best speed limiter is the drivers' right foot.
5 February 2009