More than 200 drivers a day were caught using their mobile phones illegally in the wake of a crackdown on the practice.
Police forces in Britain penalised almost 6,000 motorists for the offence in the four weeks after tougher punishments took effect, equivalent to one every seven minutes.
Campaigners said the findings suggested many drivers were ignoring repeated warnings about the dangers of using phones at the wheel despite a string of publicity campaigns and the risk of harsher sanctions.
Since 1 March, drivers who fall foul of the rules can receive six points on their licence and a £200 fine, up from the previous penalty of three points and £100. The changes mean new drivers risk losing their licence for sending a single text.
Calls for efforts to curb illegal mobile phone use intensified in the wake of a string of high-profile cases and research indicating that it is widespread.
Figures obtained after Freedom of Information requests show forces recorded 5,977 instances of the practice in the four weeks from 1 March. Seven forces did not provide figures and some cases may not have been logged at the time FOI responses were issued.
The Metropolitan police registered the highest number, at 2,037, meaning more than 70 drivers a day were caught using a handheld phone on London’s roads.
Thames Valley police recorded the second-largest total at 478, followed by Police Scotland (339), Hampshire police (280) and Cheshire police (224).
Incidents reported by police after the tougher penalties were introduced include:
A man was spotted doing his online banking while driving on the M5 motorway near Birmingham.
Norfolk police stopped a woman who was responding to a message about her lost puppy being found.
A lorry driver was fined for texting on the M2 in Kent.
A 7.5-tonne lorry was driven around a roundabout in Bournemouth by a man using his phone.
A driver was on his phone while behind the wheel of a school minibus with 10 children on board in Manchester.
The RAC Foundation said the increased penalties were “a start” but said the figures for March suggested “the key message still isn’t sinking in”.
Steve Gooding, a director of the motoring research charity, said: “Driving is a safety-critical activity that requires our full attention. Hands need to be on the wheel and eyes looking out of the windscreen, not down at the phone screen.”
In 2015, 22 people were killed and 99 seriously injured in accidents on Britain’s roads where a motorist using a mobile was a contributory factor, Department for Transport figures show.
Police say they want to make using a mobile while driving as “socially unacceptable” as drink-driving.
The National Police Chiefs’ Council lead for roads policing, Anthony Bangham, said: “Drivers need to understand that this is not a minor offence and you will be prosecuted under new, tougher penalties.”