Google and Apple have agreed to amend their audio prompts after a double fatal crash appeared to have been caused by incorrect directions from a sat-nav.

A coroner warned tech companies, including TomTom, to a risk of future deaths after a woman drove the wrong way onto the A5 near Milton Keynes.

Sean Cummings, assistant coroner, said Tracey Haybittle, 58, and Amal Mohamed Ahmed, 38, both died in a head-on collision after Ms Ahmed appeared to have followed “audio directions from her sat-nav application”.

TomTom said recent changes had been made to its verbal instructions. Apple and Google hoped changes to their audio prompts would provide clearer guidance.

In November 2023, Ms Ahmed was “following audio directions” when she drove down the slip road near the Little Brickhill junction.

In a Prevention of Future Deaths report for Ms Ahmed, the coroner noted police attending the crash saw three other vehicles “perform exactly the same manoeuvre as Ms Ahmed and attempt to travel down the slip road in the wrong direction”.

National Highways has since erected signs to prevent motorists from accessing the slip road.

Responding to the report, a spokesperson from Apple said the company would add special voice guidance for drivers heading past the A5 offramp toward the A5 onramp.

They said: “We trust that the steps we are taking will be helpful to try to avoid any future such tragic events.”

Motorists will be instructed to “continue straight at the overpass” as they travel west. While on the overpass, drivers will be instructed to “turn right onto A5 toward Milton Keynes, Bletchley”.

Google said while it was not clear whether Google Maps was involved in the incident, it had also made improvements so similar incidents did not occur in future.

It said its teams were working on improvements to the timing of audio to provide enhanced guidance in situations such as those in this case.

A spokesperson said: “This will involve an amended audio prompt as a driver approaches a junction where they would cross an overpass – ‘after the overpass, turn right’.

“We hope that this will provide clearer guidance for drivers and help reduce the risk that they make an incorrect turn.”

TomTom recommended users updated their systems after it recently implemented additional safeguards to “limit drivers’ confusion where possible”.

It said this had been done by timing the verbal commands closer to the actual exit, and after passing the off-slip road.

Follow Beds, Herts and Bucks news on BBC Sounds, Facebook, Instagram and X.