Saints bosses have “strongly advised” supporters heading to Twickenham for Saturday’s Aviva Premiership Rugby Final to use public transport.
Around 50 coaches are expected to depart from Franklin’s Gardens from 10am for the big East Midlands clash, between Saints and Leicester Tigers.
Thousands more fans are expected to travel to the home of English rugby on the train and by car.
However, the club has today urged fans not to drive, unless they have booked a car park space.
A spokesman for the club said: “Club coaches will begin departing Franklin’s Gardens at 10am on Saturday morning, with the last coach leaving at 11.30am.
“Because enough tickets have been sold to fill around 50 coaches supporters are advised to arrive at Franklin’s Gardens early enough to allow for prompt departures.
“Public car parking for travellers will be available in the Edgar Mobbs Way car parks from 9am. Car parking will not be available in the Weedon Road and Ross Road car parks.
“Coach travellers must retain their ticket for both the outbound and return portions of their journeys, and use the same coach.
“Coaches will begin returning from Twickenham once they are full, with the Rodber Suite being open at Franklin’s Gardens once supporters return to Northampton.”
The club spokesman added: “A very limited number of car parking passes at Twickenham Stadium are available now from the club. All of these passes are in the Cardinal Vaughan Car Park and cost £30 per car.
“All the roads surrounding the stadium are for resident permit holders only and any unauthorised vehicles will be towed away.
“If supporters do not have car parking passes at Twickenham then they are strongly urged not to drive to the stadium itself.
“Instead supporters should look to use public transport for at least part of their journey.”
London Midland trains will be running a normal Saturday timetable, with a recommended last departure of 12:05pm from Northampton to allow for a reasonable walking time between Twickenham Station and the stadium.
Supporters travelling by London Midland can either change at Watford Junction and use the surface line to Clapham Junction and then on to Twickenham, or head into London Euston before using the Northern Line to Waterloo and then South West Trains to Twickenham.
Alternatively supporters can drive to stations close to the M25 such as Staines or Windsor before using South West Trains for the final part of their journey.