People travelling to the tsunami relief concert at the Millennium Stadium in Cardiff are being asked to plan their journey carefully to avoid delays.
The concert at the stadium begins at 1530 GMT
As well as the 61,000 going to the concert, about 15,000 football fans are expected in the city for the Cardiff-Burnley game.
People arriving by car are advised to use park and ride facilities.
Drivers are warned a full city centre road closure will be in operation between 1300 GMT and 2330 GMT.
People arriving from east of Cardiff are advised to leave the M4 at junction 29, and those from the west at junction 33.
Park and ride facilities in Cardiff are:
- University Hospital of Wales (red car park) - drop off at rear of Cardiff Castle
- Companies House (blue car park) - drop off Hilton Hotel
- Knox Road multi-storey - park and walk at Eversheds (white car park)
- Queensgate (purple car park) - drop off at Callaghan Square
- County Hall (green car park) - drop off at Callaghan Square.
The park and ride facilities at Leckwith Stadium will not be available to concert goers or shoppers.
UHW and Knox Road both open at 0900 GMT and the first bus leaves UHW at 1000 GMT.
The others all open at 1100 GMT.
The last bus leaves the pick-up points at midnight and parks close at 0030 GMT.
Coaches are to use coach parking bays in Corbett Road and the lay-by on the south side of North Road at its junction with the Boulevard de Nantes.
The following roads will be completely closed from 1300 GMT to 2300 GMT: Duke Street, Castle Street, High Street, St Mary Street, Caroline Street, Wood Street, Central Square, Westgate Street, Quay Street, Guildhall Place, Golate, Park Street, Havelock Street and Scott Road.
Sections of the some roads will also be closed to all but traders and residents: Kingsway from North Road to Duke Street, Neville Street as far as Westgate Street, Tudor Street between Clare Road and Wood Street, Plantagenet Street and Beauchamp Street from Despenser Place to Tudor Street.
Arrival Trains Wales have said they will be providing additional and strengthened services on some routes before and after the concert.
A queuing system will be used in Cardiff Central Station after the concert ends to allow safe movement of passengers through the station.
The company advised passengers to wrap up well in case of very cold weather.
Information is available from Connect 2 Cardiff on 029 2087 2087. the Millennium Stadium website or the Traffic Wales website and for rail passengers, the Arriva Trains Wales website.