Update. 12.37pm: Reports that the A39 is now open, and traffic is flowing.
Update Noon: The A39 at at Perranarworthal is still closed due to flooding and structural concerns.
Update 9.45am: A39 at Perranarworthal remains closed while highways engineers assess condition of the leat system above.
There are also reports of an accident on Arch Hill in Truro with long delays on Morlaix Avenue.
Some school children may not be making it to school this morning, after the 007 bus to Penryn College became stuck at Ponsanooth.
There are reports of severe traffic disruption this morning with commuters facing long journey times between Falmouth and Truro.
The road through Perranarworthal is closed with the road surface in poor condition due to flooding. The road through Ponsanooth is reported to be near gridlock.
Ian Crewes, who faced a one hour and 20 minute journey from Truro to Falmouth this morning said: "I set off at 7.30am and took the route up to Chiverton, through Scorrier, St Day and Ponsanooth.
"I knew the main road was closed so I took the diversion, but the police had not stopped people parking on the road at Ponsanooth, so the traffic was not flowing.
"Where were the police, and why were the cars not stopped from parking on the main road?"
There are reports that highways engineers are worried about structural safety of A39, and that it will remain closed until an assesment is made.
Traffic also ground to a stop at the Chiverton Roundabout due to the sheer volume, with cars backing up along the Newquay Road.