Sussex Police are warning road users to take extra care on icy roads this winter after two fatal crashes in the last two days (December 28 and 29).
The vehicles are believed to have skidded off the road after going onto ice on the carriageway.
There have also been a number of less serious collisions.
Recent drops in temperature have led to roads, particularly more rural ones, becoming icy reducing grip for traffic.
The low sun is also said to be reducing visibility and causing glare in both the morning during rush hour and in the afternoons.
Motorists have been encouraged to check their vehicles are roadworthy before they start journeys, including making sure their windscreen wipers and lights are working and that their tyres are properly inflated and have plenty of grip.
They are also being urged to reduce their speed, increase their stopping distances and to be alert for how other road users are being affected by the conditions.
Cyclists have been being encouraged to make sure they can see and be seen on the roads, to check their bikes are in a good condition and to be aware of other road users.
Pedestrians are being asked to take extra care on slippy pavements and when they are crossing the road, including giving vehicles extra time to stop.
Chief Inspector Phil Nicholas, from Sussex and Surrey roads policing unit, said: “In the last two days there have been fatal collisions in Nutley and Horam and the initial investigations suggest the icy roads have been a factor in what has happened.
“The temperatures are not expected to rise over the next few days so the conditions are unlikely to improve.
“Please take extra care on your journey. If you are in any doubt, act as if the roads are icy.
“You may not be able to see the ice on the road ahead of you so please give yourself extra time to get to your destination, drive more slowly and increase your stopping distance so that you make sure you get where you want to safely.”
If you see a vehicle driving dangerously call 999 or to report a vehicle being driven antisocially text 65999 or report it at www.operationcrackdown.co.uk