Six months after he became Prime Minister, Rishi Sunak has finally honoured one of the smaller, but more eye-catching, promises he made during his party leadership campaign. He has announced an end to the building of so-called ‘smart’ motorways, citing the economic cost and safety concerns.

In doing so, Sunak has halted a near 20-year policy that has been increasingly distinguished not only by its unpopularity among the car-driving public, but by its toll in lives. Thirty-eight people died in the five years to 2020 on ‘smart’ motorways, even though they only make up a small proportion of the road network.

If the cost of smart motorways has been judged to be too high, what makes those already built any different?

Indeed, the only people who seemed wedded to the concept in recent years were successive transport ministers who apparently bought into the idea that an overcrowded road network could be expanded on the cheap.

For those who have never had the pleasure of driving on a ‘smart’ motorway, they are motorways where the hard shoulder or breakdown lane has been upgraded and brought into use as a regular lane. The carriageways are monitored by cameras, with signs appearing on overhead gantries to warn if a lane is blocked. Cheerfully orange-coloured refuges have been added at intervals to accommodate any vehicles that have the misfortune to break down.

At this point, even if you have never sat behind a steering wheel, you may have spotted a potentially fatal, and I stress fatal, flaw. How many drivers have the luck or the time to reach a breakdown refuge in an emergency? And if they don’t, how much warning will following vehicles receive if their lane is blocked? Without an instantaneous alert, even the most law-abiding drivers may be unable to slow or swerve in time to avoid a collision of the sort that has now accounted for so many lives.

For me the ‘smart’ motorway issue is also personal. A few years ago, I was driving along the M20 towards the Channel Tunnel when a left-hand drive lorry veered into my lane without warning. The impact span our car around, and I only just managed to steer it on to the hard shoulder. The car had good anti-crash protection; the glass splintered, but did not cut, and my husband and I were unhurt. A kind motorist behind stopped to check we were okay, offered to be a witness if that was needed (it was), and waited until the police came.

Now imagine (and I have imagined many times) if the same sort of accident had happened on a ‘smart’ motorway. There would have been nowhere to go – unless, of course, the lorry driver had had the foresight to pull into my path just before a refuge. Like all roads to the Channel ports, the M20 carries a large number of heavy lorries. It would have taken a miracle not to be hit – indeed, to avoid a multi-vehicle pile-up.

This is not, it should be said, how ‘smart’ motorways began. The original idea was for ‘dynamic’ lanes, where the hard shoulder might be used as an extra lane in areas, or at times, of particular congestion, and when strict limits on speed were applied. This is what happens in some continental countries and has proved generally effective and uncontroversial. Alas, successive UK governments did not stop there. Instead, the incorporation of the hard shoulder was made permanent in a version of ‘smart’ motorways known as ‘all-lanes running’.

Yet as the casualties mounted, so did the opposition. The Select Committee on Transport published a report in 2016 calling on the government not to proceed with a major investment in ‘smart’ motorways so long as safety concerns existed, saying that the trade-off between safety and reduced congestion was ‘an unacceptable price to pay’. By 2019, however, a big expansion of ‘smart’ motorways was announced. That was then paused, but not stopped, to allow for a five-year safety assessment. A new Commons committee report objected that the precautions so far announced were nowhere near enough.

None of this seriously deterred the proponents of ‘smart’ motorways, who decided that any problems were mainly down to the ignorance and poor skills of drivers. So they commissioned an advertising campaign to re-train us. A jingle sung to the tune of the Pet Shop Boys’ Go West told drivers who broke down on a motorway to ‘Go Left’. Where exactly that ‘left’ might be, on motorways without a hard shoulder, was another matter. I was one of many who lodged a complaint with the Advertising Standards Authority to the effect that this was misleading, but the ASA did not agree.

And this brings us to today. For, grateful though many of us may be that Rishi Sunak has started to put a stop to the ‘smart’ motorway madness, the campaigning will go on, tinged with disappointment on the part of those who thought Sunak would remove all smart motorways entirely.

The call, supported by both main motorists’ organisations, the AA and the RAC, is  now to reinstate the hard shoulder on motorways where it has been removed, or at very least return to the original concept of ‘dynamic’ lanes, where the hard shoulder may be opened to traffic at peak times, with strict speed monitoring. How hard could such a change be?

Supporters of smart motorways, however, have not yet thrown in the towel. They insist that ‘smart’ motorways, by relieving congestion, are safer. They believe that technological improvements are the answer and – wait for this – that one reason for our problems is the British motorist’s appetite for risk and cavalier attitude to signs (in contrast to the greater obedience of our continental cousins).

But the clinching argument has to be this: if the economic and human cost of all-lane running motorways has been judged to be too high, what makes those already built any different? Given that emergencies are rarely predictable, and that accidents can happen in a split second, it seems improbable that either the technology or we, as drivers, will ever be smart enough to make ‘smart’ motorways safe.