Analysis of more than 700,000 traffic accidents in Britain by Direct Line Car Insurance found that drivers have a 14% higher chance of being involved in a collision on Fridays than the average day.
The riskiest hour on the roads is 5-6pm, with 9% of all incidents occurring in that period, according to the study.
Motorists are least likely to be involved in an accident on Sundays when there are 24% fewer crashes than average as there are fewer vehicles on the road.
The research revealed that the total number of crashes fell by 8% between 2011 and 2015.
Gus Park, a managing director at Direct Line Car Insurance, said: "Towards the end of the week we are often tired, rushing to get home or away for the weekend, and this can lead to people not paying as much attention to the road conditions and their surroundings.
"It is important people remain vigilant every time they get behind the wheel - for their own safety and that of other road users."
Office for National Statistics figures for personal injury accidents reported to police between 2011 and 2015 were analysed for the research.
Here are the average daily number of road accidents in Britain, according to the study:
* Monday: 397.1
* Tuesday: 419.8
* Wednesday: 419.1
* Thursday: 424.0
* Friday: 453.2
* Saturday: 363.3
* Sunday: 300.7