Helston's police have announced the road closures ahead of Flora Day next week.
People have been urged not to park on the route the night before, to avoid having their vehicles towed away and prevent them from blocking the dances.
Road closures will operation from 5.30am until 11.59pm next Thursday, May 8, and will affect Meneage Street to its junction with Grange Road, Monument Road, Church Street from its junction with Coinagehall Street to its junction with Church Hill, Cross Street, St John's Road and Almshouse/Nettles Hill.
Coinagehall Street will be closed from 4.30am until 11.59pm, although the organisers have discretion to reopen the roads earlier should proceedings finish earlier than expected.
Parking restrictions will operate in these areas from midnight on May 7. Any vehicle obstructing the route or likely to cause danger to the public will be removed at the owner's expense.
The Porthleven road will be closed from its junction with the A394 Penzance Road to Squires Lane from 8pm Wednesday, May 7 until midnight, due to the fairground. This restriction will also apply from 5.30pm, Thursday, May 8 until midnight. A one-way system will operate in Ratcliffe Lane from Helston to Porthleven.
Sergeant Ashley Putman, of Helston Neighbourhood Police Team, said: “The organisers apologise for any inconvenience this will cause, but these actions are necessary in the interest of public safety to ensure that the dance routes and other relevant areas are kept clear of vehicles.”