CCTV cameras are being installed to enforce the bus lane rules east of the Rottingdean traffic lights on the A259.
Brighton and Hove City Council said that the move was necessary to tackle the growing problem of cars and vans driving in the bus lane.
Enforcement will begin in the next few weeks, the council said, meaning that drivers face a £70 fine if caught.
Bus lanes in Brighton form part of a wide-ranging programme of measures to improve the reliability and punctuality of public transport and provide extra space for cyclists.
The council said: “This in turn encourages more people to switch from the car to other forms of transport, reducing congestion and air pollution.
“The number of people travelling by bus in the city has more than doubled in recent years.
“The A259 bus lane gives priority to buses, taxis, cyclists and motorbikes.
“In a survey carried out last year between 7am and 7pm nearly 1,500 cars and vans were found driving in the last 10 metres of the bus lane and more than 600 had moved into the lane between 30 and 50 metres out preventing buses from entering the bus stop.
“The survey was done as part of the trial of motorcycles using the bus lane but the council also received complaints about delays to buses.
“This is caused by vehicles filtering into the dedicated lane before the traffic lights rather than moving over to the left at the end of the bus lane.”
Councillor Ian Davey, the Green administration’s lead member for transport, said: “We need to make sure that bus lanes are free from unauthorised vehicles so that buses can provide a reliable, efficient and attractive service to the city’s residents and visitors.
“This bus lane also offers an alternative route for cyclists and motorcyclists on a popular coastal stretch.
“It’s time to do something about the increasing numbers of vehicles driving in the bus lane at Rottingdean.”
Compliance with bus lanes in Brighton is generally good, the council said, with just 12 penalty charge notices issued for being in a bus lane on an average day.
Brighton and Hove Buses managing director Martin Harris said: “People in Brighton and Hove use their buses more than any city outside the capital and keeping the bus lanes moving for all the bus users is essential for the economic and social life of the city.”