Dumb thinking or intelligent speed limiters?

Intelligent Speed Adaptation – not so intelligent and not so adaptable 

Who’s the best person to control your throttle pedal?  You, the person behind the wheel, checking for hazards and moderating your speed according to constantly changing road conditions or your local councillor who’s worried about getting re-elected and under pressure to lower limits?  Rhetorical?  Sure.  But it’s the reality of Intelligent Speed Adaptation (ISA).  It’s in the news this week, although the idea has been around for years – as has the legislation and even the limiters themselves.

In fact, you’ll already find speed limiters in cars like the Fiat 500X, the Ford S-Max, Galaxy and Focus as well as the Mercedes S-Class, the Volvo S90 and V90 and the Jaguar F-Page and XF.  The Honda Jazz also has a limiter; conclusive proof that even bureaucrats have a sense of irony.

These ISA systems use cameras at the front of the vehicle which ‘read’ speed limit signs and either cut power to the engine (if the driver is above the limit) or remove throttle response so you can’t exceed it. As Jaguar says, “If the system detects a speed limit lower than the current vehicle speed, it automatically slows the vehicle to meet the speed limit.”  The system won’t brake for you, but will adjust the fuel flow to the engine, effectively slowing you down to meet the limit or prevent you exceeding it.

If the cameras don’t spot the signs, there’s a back-up linked to the car’s GPS satellite navigation with a handy database of speed limits.

At the moment, there are three flavours of ISA, each exercising progressively more control over the driver.  The lowest level of interference comes from an ‘informing system’ which either beeps at you until you slow down, flashes a warning light or both.  ‘Half-open’ systems will warn you when you exceed a limit and also stop you doing it by taking away your throttle control – but you can still override it.  Finally, closed systems give you no choice – you stick, limpet-like, to the limit with no ability to outrule the computer. 

At the moment, most systems are half-open and drivers can still choose whether or not to engage ISA.  The European Transport Safety Council has said it “…supports a full on/off switch for the system…” but only, it adds, “…to aid public acceptance at introduction.”  The direction of travel is pretty clear. 

Interestingly, carmakers are selling ISA to the public more as a way to avoid a ticket than as a safety aid.  Roelant de Waard from Ford of Europe says. “Intelligent Speed Limiter is one of those technologies that people will wonder how they did without – not just because they avoid speeding fines but because driving becomes that much less stressful.”

And, for many drivers – the less enthusiastic sort – that looks, at first glance, like a good shout.  If you buy a domestic appliance car and simply regard it as a way to get around that’s better than the bus, ISA will certainly stop you getting ticketed.  You can simply avoid turning the system off and let your car do the thinking for you.

But handing over control of your throttle pedal comes at a price.  Even the European Commission – one of ISA’s biggest fans – admits there are problems.  They talk about three main issues: diminished attention, over-confidence and frustration and admit “At present there is insufficient insight into the size of these possible negative side effects and their consequences.” That seems quite a gap for a system that’s already being rolled out across Europe. Fancy being a beta tester for something that controls your car?

We know already, from studies at the University of Leeds, that ISA makes drivers more frustrated and anxious.  Anyone who’s tried sticking to a limit with an aggressive tailgater will know the feeling and it’s hardly conducive to safe driving.  Worse, the ISA-generated anxiety and frustration are highest on motorways and in 20 limits.  

The studies also showed an increase in amber light running. Presumably drivers felt it was better to just keep rolling than stop – or perhaps they had just switched off from the task of driving.  They also tailgated more before overtakes and “cut in more aggressively when driving with an active mandatory ISA system” too.

Surprisingly, the Leeds study also measured the effect of ISA on drivers’ ‘joy’.  Unsurprisingly, it seems driving with a bureaucrat’s foot controlling the accelerator results in a significant decrease in enjoyment.  Perhaps that’s part of the idea. H.L. Mencken had it right: “Puritanism: The haunting fear that someone, somewhere, may be happy.” 

Given that the Commission and Leeds University’s transport academics aren’t exactly known for their love of the open road, it’s pretty fair to assume that ISA is being imposed on drivers more in hope than understanding.

But perhaps the weakest link in the whole ISA chain is the way speed limits themselves are set. For ISA to have credibility, the basis for speed limit setting needs to be scientific, evidence-backed and robust.  In fact, limits are set by councillors, often with no road safety background. Instead, they’re concerned about re-election and under pressure from residents who fear cars are travelling ‘too fast’ – even when there’s no history of accidents. 

Perhaps the road safety industry is concentrating on what it can measure rather than what’s important. The European Transport Safety Council, one of the groups backing ISA, certainly seems to be. “Speed is the number one killer on Europe’s roads, it claims.” It also says that ISA will reduce crashes by 30 percent and save 25,000 lives over 15 years.

This view is a little hard to square with the UK government’s stats. According to the Department for Transport, in 2018 ‘exceeding (the) speed limit’ was a factor in just 5% of crashes.  Compared with “failed to look properly” at 38% and “Failed to judge other person’s path or speed” at 20%, there seems to be a measure of governmental gnat-straining going on.

And the obsession with speed limits just isn’t working. Despite the millions spent on lower limits, limiters and speed cameras, fatalities and serious injuries have stopped falling – since 2010 they’re flatlining.  The Government is now so worried about the lack of improvement in road safety that they’re launching an inquiry to find out why. 

If one looks deeper, there are plenty of studies which, rather than forcing compliance with an increasingly arbitrary limit, emphasise the importance of developing drivers’ hazard perception abilities.  These are the trainable skills that enable good (i.e. safe) drivers to spot dangerous traffic situations and take the best action – whether that’s slowing down or simply anticipating and planning ahead.

Given the issues with ISA – and with increasingly hardline speed limit enforcement as a whole – we might be better making ongoing driver training a condition of retaining a licence, perhaps linked to reduced insurance premiums from lower risks. It’s got to be better than letting a bloke behind a desk in county hall control your accelerator.