Nearly two in five motorists drive without due care and attention, with Leeds having the worst road users, according to a new survey.
Independent researchers for insurance company Direct Line checking the driver behaviour of 11,000 motorists in 10 UK cities found 37% drove carelessly.
Failing to indicate was the most common offence, followed by failing to stop at a pedestrian crossing.
A total of 5% of motorists regularly flouted the mobile phone rules, with Birmingham drivers the worst culprits in this respect.
After Leeds, the motorists driving the most carelessly were those from Manchester, followed by Bristol, London and Birmingham. The most considerate drivers were found in Norwich.
Direct Line motor spokeswoman Emma Holyer said: "We conducted the research to find out how many drivers are flouting the law and our findings are shocking.
"Careless driving is a major cause of accidents, and aside from the increased risk of causing a crash, a careless driving offence carries severe penalties.
"So we are reminding motorists to take care, keep their full concentration on their driving and brush up on the rules as detailed in the Highway Code."
