An increasing number of local authorities are "secretly switching off street lights", the AA has claimed.
The association has said that the lack of street lighting will lead to an increase in the number of car crashes and the amount of crime.
Previous research has shown that although only a quarter of all car travel happens between the hours of 7pm and 8am, 40% of fatal and serious injuries occur at this time.
And to support its claims that turning off lights would be dangerous, the AA has pointed to research undertaken for the Department for Transport in 2003, which showed that night-time accidents were more likely to be fatal when there was no street lighting.
AA president Edmund King said that, as well as motorists, cyclists and pedestrians were more at risk on unlit streets.
"Turning off street lights to save money or reduce CO2 may backfire in terms of increased accidents and crime," he said.
"In the dark drivers' reactions tend to be slower and stopping distances longer. Street lighting can reduce the risk of crashes and their severity."
In response to claims about its motorway lighting policy, the Highways Agency said that it will only consider switching off lighting on "sections of motorway which link junctions and which are known to have a good safety record and low traffic flows in the early hours," and that junctions would remain lit.
"Safety is and will continue to be a top priority to us," a spokesperson said. "Very detailed and thorough safety risk assessments will be completed and reviewed, along with close engagement with interested groups and of course with the public - our road users."
