The council is urging anyone visiting Cardiff or travelling through it on Friday to plan ahead and consider leaving their cars at home, with ten city centre roads confirmed to be either fully or partially closed between 6am and 6pm.
If large crowds turn out to see His and Her Majesty, a further four city centre roads could close "as a contingency."
Additional road closures will also be in place in Sophia Gardens, Llandaff and Cardiff Bay.
Cardiff Council says the closures are necessary to both facilitate the Royal visit and keep the public safe.
Cardiff city centre road closures
From 6am until 6pm on Friday September 16th, the following roads will be closed:
North Road between Boulevard de Nantes and Kingsway
Kingsway from North Road to Duke Street
Duke Street throughout its length
Castle Street throughout its length
Wood Street between Westgate Street and St Mary Street
St Mary Street from Custom House Street to High Street
High Street throughout its length.
Cowbridge Road East between Westgate Street and Cathedral Road but access will bemaintained.
If large crowds materialise, then the following road closures may also be put in place:
Lloyd George Avenue throughout its length
Herbert Street between Lloyd George Avenue and Callaghan Square
Callaghan Square from Dumballs Road to Bute Street
Full length of St Mary Street until Callaghan Square.
From 6am until 6pm on Friday, September 16th, the following roads will be closed:
Sophia Close – service users must use the pay & display car park accessed viaCowbridge Road East
Limetree Avenue – exit for the campsite will be via Dogo Street
The following roads are already closed and will not re-open to motor vehicles until Saturday, September 17th:
Access is currently being controlled into the area for those on foot, or on bike, with alternative parking available for motorists at the pay & display car park and on Fairwater Road.
From Thursday, September 15th at 8pm until Friday, September 16th at 4pm, the following roads will be closed in their entirety:
Heol-y-Pavin (access maintained)
Bridge Street (access maintained)
If large crowds materialise, the following roads will also be closed:
Cardiff Road from the junction with Llantrisant Road to the junction with WesternAvenue
Fairwater Road to the junction with Pwllmelin Road (access maintained)
The following roads are already closed and will not re-open to vehicles until Fridayafternoon:
All those travelling to Cardiff for the Royal visit are advised to plan their journey in advance and leave plenty of time to get into the city and use public transport wherever possible.
Local residents are strongly encouraged to leave their cars at home and either take the bus or train or walk and cycle if they are able to.