More than half of motorists say obscured signs are a frequent occurrence on their journeys, according to a survey by the RAC.
The motoring organisation said the findings reveal that out-of-control foliage can have a detrimental effect on road safety.
Three-quarters (74%) of drivers say speed limit signs are the most likely type of sign to be covered up by overgrown foliage, with 30mph signs the most commonly obscured.
While 53% of motorists said obscured signs are a frequent occurrence on their journeys, a further 39% said signs are occasionally harder to see in the warmer months.
Only one in 12 drivers (8%) said obscured signs are not a problem on roads near them.
More than half (52%) of drivers said 30mph signs were the most obscured by foliage, while a further two in five (39%) said 40mph signs were hardest to see and 16% said 20mph signs were overgrown.
Drivers said red circle and ‘give way’ signs were difficult to detect
More than two in five (42%) of the motorists who noticed signage obscured by foliage said it led to them accidentally breaking the speed limit, and a quarter (26%) said they missed important information that compromised theirs or someone else’s safety.
The RAC said it was concerning that ‘red circle’ signs, which tell drivers what they must do, seem to be most often hidden by untrimmed trees and bushes.
RAC Breakdown spokesperson Alice Simpson said: ‘Drivers shouldn’t be left to rely on their local knowledge and navigation apps to know if there’s a change in speed limit or if a junction is approaching. And new in-car systems that normally detect road signs and display them on the dashboard are redundant if a sign isn’t visible.
‘While we realise local councils are under enormous pressure financially, we nonetheless ask them to inspect all the signs on their networks and do everything in their power to ensure they are clear and visible to drivers, as it’s these signs that can save lives.’
