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 IV is nearly upon us. The showpiece event, held for the fourth year running at the Principality Stadium, will see Cardiff Blues facing Ospreys, followed by the clash between Scarlets and the Dragons.
For the past two seasons you may have noticed an artist in the crowd and drawings appearing on twitter and TV. These collections of drawings were all produced from life, on the spot without the use of a camera in order to capture the vibrancy, emotion and atmosphere of the moment.
Join Cardiff Blues for Wales' home matches in the 6 Nations with our fantastic hospitality packages at BT Sport Cardiff Arms Park - but act quickly to take your place with our Scotland packages now SOLD OUT!