Drivers are advised to take extra care on the roads with heavy hail showers predicted in Devon and Cornwall.
Police and Highways England dealt with a number of road traffic incidents in adverse weather conditions on the A30 during the morning of February 28, particularly on higher ground around Bodmin and Redruth.
It generally takes at least twice as long to stop on a wet road as on a dry road because tyres have less grip on the surface.
In wet weather you should:
Slow down if the rain and spray from vehicles is making it difficult to see and be seen.
Keep well back from the vehicle in front as this will increase your ability to see and plan ahead.
Ease off the accelerator and slow down gradually if the steering becomes unresponsive as it probably means that water is preventing the tyres from gripping the road.
Tim Bagnall, operations manager at the Highways England Regional Control Centre, said: "Due to the unique geography of the South West peninsula we regularly experience significant localised hail showers."
"These can happen with very little warning resulting in short lived but treacherous driving conditions."
“We would urge drivers to take note of weather forecasts prior to making their journeys and remain vigilant at all times. Whilst these weather events can occur anywhere, we have seen particularly heavy shower events on the A30 in Cornwall in the Redruth area and across Bodmin.”