Strabane Royal Black District Chapter No 2 will host a parade in Donemana on Saturday, August 30.
A total of 25 bands and preceptories are scheduled to take part. They are expected to start arriving in the village from 10.30am.
The main parade will set off from the assembly field, which is opposite Earlsgift Church on the Longland Road, at 1.30pm or thereabouts, returning there for a religious service.
From about 4pm, visiting bands and preceptories will parade from the field to their buses.
Roads will be closed from 12.30pm and no traffic will be allowed onto the parade route after this time.
A PSNI spokesman said diversions will be signposted away from the village using the surrounding ‘back roads’.
WThese roads are both narrow and winding in places, therefore drivers of large vehicles are asked to avoid the area altogether. Roads will be reopened again at around 5.30pm.
“The route through Donemana is a popular one for motorists travelling to and from Belfast and the international airport, and anyone make this journey on the day of the event is advised to seek alternative routes,” the spokesman said.