Lane-hoggers now face instant fines
The level of fines for some existing offences, such as using a mobile phone while driving, will also rise.
But the changes seem set to go down badly with motorists, with a recent poll of 3,000 drivers by Auto Trader showing that 60% reckoned the new fines would make no impact on road safety.
And an AA/Populus survey revealed that 29% admitted to sticking in the middle lane of motorways, with the AA adding that the Government had not done enough to warn people of the new penalties.
The lane hogging and tailgating fines are part of changes giving the police powers to issue fixed-penalty notices for careless driving. The penalty will be £100 with three points on the driver's licence. The most serious examples will continue to go through court, where offenders may face higher penalties.
The police will also be able to offer educational training as an alternative to endorsement. Drivers will still be able to appeal against any decision in court.
The changes give the police greater flexibility in dealing with less serious careless driving offences, freeing them from resource-intensive court processes.
Also from tomorrow, various fines, for which drivers do not have their licence endorsed, rise from £30 to £50. These include such offences as not having an easily-seen car tax disc and failing to give way at a junction.
Other fines, such as using a mobile phone at the wheel, and some speeding offences, rise from £60 to £100. These offences lead to an endorsement on the licence.
The fine for failing to wear a seatbelt also goes up from £60 to £100, while the driving-without-insurance fine rises from £200 to £300.
Road Safety Minister Stephen Hammond said: "Careless driving puts innocent people's lives at risk.
That is why we have made it easier for the police to tackle problem drivers by allowing them to immediately issue a fixed-penalty notice for low-level offending rather than taking these offenders to court.
"We have also increased penalties for a range of driving offences to a level which reflects their seriousness and which will ensure that they are consistent with other similar penalty offences."
First announced earlier in the summer, the changes are being introduced following extensive public consultation with road safety groups and police forces.
The Department for Transport said fixed penalty levels for most of the motoring offences in tomorrow's changes had not increased since 2000, making them lower than other penalties of a similar severity.