Motorists have been advised to avoid Derry city centre from 5 p.m. this afternoon while the National Cycling Championships visits the city.
Roads were closed for three hours this morning and will close again at 5 p.m. for three hours for the second race of the day.
Motorists are advised to expect traffic disruption around Shipquay Street, the city centre and Spencer Road.
The race will involve five laps of a 21 km course returning via Foyle Bridge and Culmore roundabout.
There will be further road closures on Sunday between 10 a.m. and 2.30 p.m.
The first race is at 7.50 a.m. and will consist of two laps of the same course as Saturday.
The second race begins at 9.50 a.m. which is due to finish at approximately 2.30 p.m.
Motorists are asked to avoid the areas on both days during the times mentioned.