More data is coming in that shows electronic safety systems – especially automatic emergency braking – really do cut accident rates.

We reported on the first UK data about this in April, but new data has now emerged from the USA. The federal Highway Loss Data Institute (HLDI) says that accident rates were 14% lower in cars fitted with Autonomous Emergency Braking (AEB) – what Ford calls City Stop.

It said warning systems that alerted the driver to an obstacle but did not brake the car showed less improvement. We are not surprised about that – such systems tell you via a light and a noise that something is wrong, but you then have to take a fraction of a second to figure out what the message is all about. If you have not already noticed the obstacle, it is probably then too late.

The other piece of technology that makes a significant difference is adaptive headlights, which turn with the steering wheels. These appear to reduce accidents by 10%, which is a remarkably high figure for something relatively straightforward. Incidentally, that must make Citroen feel a bit smug: they pioneered mechanically swivelling headlights on the DS in the 1960s, but buyers did not want to pay the premium.

Interestingly, the one safety feature which makes no difference (at least in the data collected so far) is lane departure warning. These show no measurable reduction in accident rates, which rather pleases us. Getting a vibro-massage every time you cross a white line without using your indicator is irritating – and even the Institute of Advanced Motorists says that you should not use an indicator signal if no other motorist would benefit from that signal.