Motorists are putting lives at risk by using the hard shoulder as a shortcut on the M62.
Police and highways officers have warned that people found using the hard shoulder to overtake traffic or reach exit sliproads more quickly could be given penalty points on their licence.
They said abuse of the hard shoulder was a growing problem, which could delay emergency vehicles from reaching crash victims.
Roads policing inspector David Peach said: “There may be a vehicle broken down or a stationary vehicle in front of you which needs assistance.
“If we have an incident on the motorway our primary objective is to save life, and if this passage is blocked, the delay in getting there could be the difference between life and death.”
The warning is particularly important with the M62’s managed motorway scheme about to open fully this autumn.
It will mean that motorists travelling between junctions 25 and 30 will be told which lanes are open and closed by overhead electronic signs.
At peak times only, the hard shoulder will become a fourth running lane, as indicated by the signs.
But in similar schemes elsewhere in the country, such as on the M42 near Birmingham, a small minority of motorists have been found ignoring the signals in order to jump queues.
Insp Peach added: “If you see a red ‘x’ in the lane you are in, then it’s time to move out of that lane.
“If people do not comply then we will have no option but to go for enforcement. It will lead to a prosecution, a day in court and points on your driving licence.”