Severe weather has been blamed for a six-vehicle pile-up on an A road heading towards the M4 during a hailstorm.
According to a driver, the hail had left a section of the A4232 near Culverhouse Cross so slippery it was like "driving on an ice rink" on Wednesday afternoon.
Ambulance crew and a fire engine rushed to the scene where one person is reportedly being treated by paramedics.
Officers from South Wales Police are also at the scene.
Photographs taken at the crash shows a number of vehicles including a small van were involved.
Hail and sleet can be seen on the floor, which South Wales Traffic has said are causing dangerous driving conditions.
Traffic South Wales is urging drivers to avoid the area if possible.
It said there are “very poor driving conditions due to hail and ice”.
Sophie McMillain warned drivers about the treacherous conditions on Twitter.
She tweeted: "If you have to drive on the A4232 do so with extreme caution. Multiple crashes, road condition are very very bad."
The crash comes as frustrated drivers were stuck on part of the M74 in Scotland for hours overnight due to snow and ice.
The Met Office warned snow and ice may cause disruption, with snow likely on higher ground.
Police said the M74 was shut between junctions 14 and 15 northbound for a time overnight but was passable with care on Tuesday morning.
Cheryl Burnett said it took her six and a half hours to get from Dumfries to Glasgow, with four and a half hours stuck on the motorway.
After leaving Dumfries just after 9pm on Monday she arrived home at about 3.30am, a journey which normally takes around an hour and a half
She said: "When I left Dumfries on the A701 the driving conditions were worsening by the minute.
"I was hoping I could get to the M74 because I thought it was going to be clearer than the A road I had been on and when I got to the M74 it was OK and you could follow someone else's tracks but then it just came to an absolute grinding halt because visibility was so poor and the cars all came to a standstill.
"I had stuff in the car like blankets so it was just a case of waiting."
She added: "I thought we were going to be there all night so I turned off the engine and layered up.
"It was an eye-opening and terrifying experience."
Traffic eventually started moving again, though slowly, at around 2am after a gritter went past and she reached home in Glasgow at about 3.30am.
She urged people to make sure they have blankets, food and something to drink stored in their car in case they ever find themselves in a similar situation.
Another motorist tweeted he was stuck for an hour and another reported that he was stuck for an hour and a half.
Police in southern Scotland advised people to leave extra time for their journey and drive according to the conditions.
