Sefton Central Labour MP Bill Esterson is urging motorists to take greater care on Formby Bypass.
The MP's call comes in the week that a man lost his life following a fatal crash on the busy road.
The speed limit on the road was cut from 70mph to 60mph last year in an attempt to make the road safer.
But the tragic death of the 49-year-old Southport man this week, is the latest in a line of fatal accidents on the road.
Bill said: "Because Formby Bypass is a long and fairly straight road, some motorists do feel that they can put their foot down.
"Even despite the best efforts of the Highways Agency to make safety improvements, which includes the reduction in the limit from 70mph to 60mph, there are people who are speeding along the road.
"It seems obvious to say, but when a crash occurs at speeds in excess of 60mph, then the results are more often than not fatal."
Bill said: "There is a legal limit on Formby Bypass, but sadly, some motorists ignore the speed limit, while others don’t take enough care over how they drive.
"If some motorists aren't willing to stick to the limit, then maybe the police will need to intervene and carry out regular speed checks on this dangerous stretch of road.
"I would urge motorists themselves to slow down. Is it really worth risking your life, or the lives of others just to get where you are going two minutes earlier?"
Bill added: "I would like to send my heartfelt condolences to the family and friends of the man who died this week."