Wales’ Six Nations game with France and an unrelated march are expected to affect travel in Cardiff city centre on Saturday.
Cardiff council has announced city-wide temporary road closures and a rolling road block for an anti-racism march.
Rugby fans have been advised to arrive early at the Principality Stadium due to “enhanced security measures” ahead of the kick-off at 17:00 GMT.
Road closures will be in place between 13:00-18:00.
Planned rail engineering works will add 50 minutes to Great Western Railways services between Paddington and Cardiff and return services, with routes diverted and replacement buses.
Buses moved from stops within the closure area will relocate to either Churchill Way for the east, Greyfriars Road for the north or Tudor Street for the west.
The March Against Racism includes a host of speakers including community leaders and politicians.
It starts at Grange Gardens, from 12:30, marching through Grangetown and Riverside to City Hall.
In the rugby, both teams have the opportunity to finish second in the Six Nations table, but could drop to fifth with a loss.