The warning, from police, came as a section of Peel Road in Lytham – and several nearby junctions – were closed following a crash involving a VW Passat and Lotus at around 7.45am.
One of the cars had spun and crashed into a fence near to Hybank Farm, police said.
The male driver of the Lotus escaped with minor injuries, suffering a twisted ankle, a spokesman for the force added.
He said: “Drivers need to be extra careful because of the conditions. They are treacherous.”
One eyewitness said lengthy tailbacks had built up during rushhour, and said motorists were forced to u-turn after getting caught up in the crash’s aftermath.