Swansea fans forced to drive to the LDV Vans final at the Millennium Stadium because there are no trains face a 100% rise in park and ride fees on arrival.
Cardiff Council is increasing the cost of the service to £10 the day before 30,000 football fans are expected to journey east along the M4.
Coach operators have also warned they are running out of vehicles, which could force even more fans to use cars.
Cardiff Council said the rise on 1 April was due to increased costs.
Rugby fans for last Saturday's Six Nations match with France paid £3.50, and the cost for football fans up to the end of March has been £5 per car.
The council said that football matches required more park and ride sites because of the need for segregation of supporters.
Network Rail is closing the line between Swansea and Cardiff on 2 April for engineering works meaning everyone travelling east to the game will have to go by road.
Swansea have sold 10,000 tickets to season ticket holders and the club expects to sell a further 20,000..
Fans started queuing for tickets at 0600 GMT on Thursday when they went on general sale and by mid morning there were over 100 waiting in line.
The Official Swans Travel Club said it had already filled 33 of the 36 coaches it had been able to secure to date.
"It's becoming a struggle to get coaches - not to fill them up," said a spokesman.
"Ten years ago when we last had such a big exodus there were far more coach companies in the local area.
"It's not just us looking for coaches - its sports clubs, social clubs, everybody.
There were long queues as tickets went on general on Thursday
"Many people will have to drive. I would image the M4 could be like a car park."
The AA has warned motorists that a contraflow system will be in place on the day at the M4 at Margam with a 50mph speed limit.
It is advising supporters to car share where possible and to leave plenty of time for the journey.
SWANS' FANS TRAVEL
Coaches: M4 Jct 33 for Lloyd George Ave
Cars: M4 Jct 33 for Leckwith (yellow carpark), Queensgate (purple) and County Hall/UCI (Green)
Bus drop off points at Tresillian Way behind station, north of Callaghan Sq and Bute Terrace behind ice rink
Park and ride 0800-1830 GMT, cost £10 per car, last bus pick-ups 1800
Coach/minibus free passes: 029 20 822145
Source: Cardiff council
Cardiff Council said part of the reason for doubling the cost of its park and ride service to the Millennium Stadium was to encourage car-sharing.
From 1 April, the cost for international rugby and local football matches rises from £3.50 to £5 per car and for football matches involving away teams it is rising from £5 to £10.
A spokeswoman said: "The increase in charges will reduce the burden of event-related costs falling on the council tax payer."
The council said it also reflected the increasing cost of operating the large number of buses needed.
"In addition, the availability of suitable sites for the park and ride operations is reducing as land is developed.
"Large football events, particularly those where segregation by team is required, involve the use of more sites that are not council-owned and, therefore, incur greater costs."