Drivers are being urged to disregard sat nav directions that reroute them onto rural roads.
The plea from road safety charity IAM RoadSmart comes as its recent survey found 54% of motorists are being diverted onto country lanes to bypass congestion on motorways, dual carriagewayss and other major A-roads.
The warning comes as Department for Transport (DfT) figures for 2024 reveal 60% of road deaths in Britain occurred on rural roads, despite carrying only 45% of traffic.
IAM RoadSmart highlighted inherent dangers: agricultural vehicles, narrow lanes, and restricted visibility from roadside foliage.
It warned that without increased capacity on major roads, more drivers risk being directed onto unfamiliar, hazardous rural routes.
Then-prime minister Rishi Sunak cancelled all future smart motorway projects in April 2023 because of safety concerns.
All lane running smart motorways – which boost capacity by converting the hard shoulder into a live lane – were rolled out from 2014.
IAM RoadSmart director of policy Nicholas Lyes said: “Every year, more people are killed on a rural road than any other road type, yet worryingly we’re seeing a high number of people taking unplanned diversions to use them.
“Congestion is inevitable, but we would encourage people to question if a diversion onto an unclassified or single-track route is worth saving a few minutes, considering the increased hazards they might face.
“Often, other people following sat navs will similarly divert and you end up with traffic volumes that exceed what the road is designed for.
“Traffic growth shows little sign of abating, yet without a commitment to increase capacity on the wider strategic network, we may see more traffic filtering onto the rural road network, with potentially grave consequences.”
– The survey of 1,042 UK motorists and 114 IAM RoadSmart motorbike riders was conducted by research company Online95 in February.

