Emergency services are advising drivers to take an alternative route after a lorry overturned on the A470.
It happened just before 11:00 BST on the A470 northbound near the Coryton interchange. Police say the slip road is closed and diversions are in place.
Heavy traffic is expected across much of the city this afternoon as Australia take on Fiji in the World Cup at the Millennium Stadium.
One lane is closed and there is queueing traffic after an accident on the A470 at A4054 Coedpenmaen Road / A4223 / Bridge Street / Ynysangharad Road (Bridge Street Interchange).
One lane is closed and there is queueing traffic because of emergency repairs on the A470 Northern Avenue inbound before Ty'n-Y-Parc Road (Whitchurch High School). There is congestion on the M4 to J32 A470 / A4054 (Coryton Interchange).
There's queueing traffic because the road is blocked after a car fire on the A470 Northbound between Abercynon Roundabout and Abercanaid Roundabout.
One lane is closed and there's queueing traffic for three miles after an accident and recovery work on the A470 Northbound near the B4275 (AberCynon South)
There's congestion to the A4054 (Bridge Street Interchange).
The A470 has re-opened after earlier accident investigation work between A4059 / A472 (Abercynon Roundabout) and A4060 (Abercanaid Roundabout).
The A470 Crimea Pass is just passable but there are hazardous driving conditions because of snow between Blaenau Ffestiniog and Betws-Y-Coed.
One lane is closed and there's queueing traffic for six miles after an earlier accident and a broken down van on the A470 Southbound at the A4054 (Upper Boat Interchange)
There's congestion on the A470 to the A4059 (AberCynon Roundabout).
There's queueing traffic and one lane is closed after a multi-vehicle accident on the A470 Southbound at the A4054 (Upper Boat Interchange).
There's congestion on the A470 to the A4054 (Bridge Street Interchange).
One lane is closed and there's queueing traffic after three accidents on the A470 Northbound between the A4059 / A472 (AberCynon Roundabout) and the A4060 (Abercanaid Roundabout).