More than 10,500 motorists in and around Sheffield have points on their driving licences for using their mobile phones behind the wheel.
Figures released by the road safety charity Brake reveal 8,459 men and 2,076 women living in areas with an S postcode have had their driving licences endorsed for phone use.
The statistics come as Brake launches its flagship campaign Road Safety Week today.
It is being supported by Vincent and Margaret O’Sullivan, the parents of Jemma O’Sullivan, aged 22, who was killed in a crash caused by a texting truck driver on the M18 near Doncaster in September 2010.
Vincent said: “It is unbearable to think Jemma was killed for the sake of a text message.
“We are appealing to all drivers - please don’t kid yourself you can get away with multi-tasking at the wheel. No text, call or other distraction is worth taking someone’s life and inflicting terrible suffering on an innocent family.”
In Sheffield alone the offenders number in their thousands.
In the S5 postcode area, which covers motorists living in Parson Cross, Firth Park, Shirecliffe, Shiregreen, Southey, Longley, Fir Vale and Wadsley Bridge, 399 men and 90 women have been caught using their phones while driving.
In S6 - Hillsborough, Walkley, Malin Bridge, Stannington, Upperthorpe, Fox Hill and Bradfield - there are 313 men and 78 women.
Drivers in S10 - Broomhill, Broomhall, Crookes, Crookesmoor, Crosspool, Fulwood and Ranmoor - account for 221 of the offenders, 167 of them men, 54 women.
And in S8 - Woodseats, Batemoor, Beauchief, Greenhill, Jordanthorpe, Lowedges, Meersbrook and Norton - there are 327 drivers with points on their licences for mobile phone use, 257 of them men and 70 women.
The campaign calls on all drivers to turn off their phones when they get behind the wheel, or put them in the boot - and everyone is being urged to refuse to speak on the phone to someone who is driving.
Brake spokeswoman Sarah-Jane Martin said: “Many people who wouldn’t dream of drink driving are succumbing to using their phone and other distractions while driving, oblivious that the effect can be similar and the consequences just as horrific.”
It is almost a decade since handheld mobiles at the wheel were banned.
The Association of Chief Police Officers is supporting the week by coordinating heightened police enforcement, targeting drivers on hand-held phones. Forces including South Yorkshire are running activities.