The Millennium Stadium is the stage for a feast of rugby this weekend and fans are advised to plan their journeys into the city centre early to avoid congestion and costly parking charges.
The semi-final double header sees Sale Sharks take on Leicester Tigers at 2.30pm and Cardiff Blues face the Ospreys at 5.15pm on Saturday March 24.
An estimated crowd of 50,000 is expected at the stadium and the best way for fans and visitors to travel to Cardiff is on public transport.
If you do bring your car into the city, fans should consider car sharing and using the park and ride services.
The park and ride sites can be accessed from J33 of the M4. You can park at County Hall (Green car park) where the drop off point is on Callaghan Square in the lay-by by Eversheds. Park and ride costs £5 per car which includes a return journey on the bus.
Coaches should leave the M4 at J32 and use the parking at the Civic centre. Parking opens at 9am. The last bus will leave the pick-up point at 8.30pm, with the car park closing at 9pm.
There will be a small road closure of Westgate Street from 1pm - 8.30pm.
The following roads will be closed for coach parking between 6am and 8pm -
King Edward VII Avenue from its abutment with Boulevard-de-Nantes to its junction with Corbett Road;
Museum Avenue from its junction with Gorsedd Gardens to its junction with Corbett Road;
City Hall Road / College Road from their junction with Museum Avenue to their junctions with North Road.
Judgement Day is back at the Millennium Stadium for 2015 with the Welsh Rugby Union (WRU) and Regions confirming today that tickets will cost just £10 per head to see all four of Wales' GUINNESS PRO12 sides in action under one roof.
Battling Cardiff Blues produce a performance of full pride and heart in adversity as they lost out to reigning champions Leinster Rugby in a pulsating Guinness PRO12 encounter at BT Sport Cardiff Arms Park.
Cory Allen scored the only try of the game as Cardiff Blues edged an absorbing and dramatic Welsh derby with Newport Gwent Dragons at Rodney Parade to open 2015 in the Guinness PRO12 with a crucial victory.