The Highways Agency is advising road users to drive with extra care in the current wet conditions and prepare for travel disruption from early on Saturday (8 February).
The HA alert follows a similar one from Sussex Police and comes in the light of the severe weather being forecast for across the south east of England in the next 24 to 48 hours.
There are currently delays of two hours on part of the M25 due to flooding from nearby saturated land, and the Met Office has issued a severe weather alert.
It is forecasting strong winds and rain across the south of the country with the potential of wind gusting at up to 80mph in the Straits of Dover and a low risk of river and surface water flooding.
Highways Agency South East Emergency Planner, Oliver Brown said: “The Highways Agency is working closely with the Met Office and other partners to monitor conditions and keep the road network running safely.
“But I’d like to encourage everyone making a journey by road over the weekend to be alert to the weather conditions and to drive with extra care.”
Due to forecast weather, planned maintenance work for this weekend in and around the M25 has been cancelled.
The planned overnight closure of the A3 Hindhead Tunnel tonight (Friday 7 February) and tomorrow night (Saturday 8 February) has also been cancelled.
Ms Brown added: “High winds can affect any section of road, especially those on coastal routes like the A27 and high bridges like the Queen Elizabeth II Bridge at the Dartford Crossing or the A2 Jubilee Way near Dover.
“Be aware of sudden gusts of wind, and give high-sided vehicles, caravans, and motorbikes plenty of space. In the event of persistent high winds at the bridges we may need to close them to traffic for a period, so please be alert for warnings of closures and follow signposted diversion routes.
“I would also like to remind drivers that it takes twice as long to stop when the road is wet, so leave plenty of space between vehicles, and slow down if heavy rain or spray is making it difficult to see the road ahead.”
At present, lanes 1, 2 and 3 of the M25 clockwise at junction 16, for the M40, Buckinghamshire, are closed due to flooding from nearby saturated land following heavy rain overnight.
The Highways Agency and our contractors are working with Buckinghamshire County Council to clear the floodwater and open the remaining lanes as soon as it is safe to do so. There are delays of approximately two hours and road users are asked to plan ahead and avoid the area if possible.