Thousands of people are expected to take to the narrow streets of the East Sussex town of Lewes on Friday to celebrate its annual bonfire event.
It is the largest annual policing operation in the county, and 400 police officers will be deployed.
The Lewes Bonfire Council, which represents the town's bonfire societies, has urged people living outside the town not to try to attend.
Roads in the town will be closed, and trains and parking will be restricted.
Southern Railway said as with previous years, there would be a queuing system in place at Brighton station from 1500 GMT onwards for trains to Lewes.
Queuing systems will also be in place at Falmer, London Road and Moulsecoomb stations, while for return journeys there will be a queuing system in place at Lewes station.
Six Lewes bonfire societies will take part in more than 30 processions through the streets of the town.
The event will culminate in six bonfire and firework displays at various locations.
Supt Tony Blaker said: "If you plan to go to the Lewes Bonfire, please note that there will be considerable delays on train services and road access is restricted.
"Any cars parked in contravention of the road closure orders will be removed, so please don't drive to Lewes unless you have arranged somewhere to park."
The event starts at 1700 GMT, with firework displays from about 2130 GMT.