Wales snow: Ice risk threat as temperatures plunge
Freezing conditions are continuing to cause travel problems with temperatures as low as -4C forecast overnight.
A snow warning remains in place in north east Wales on Sunday although the worst of it appears to be over for now.
However, ice is still making roads treacherous, with a Met Office warning in place in south Wales for Monday and Tuesday.
A handful of school closures have been confirmed so far for Monday, as parents are told to monitor council websites.
The Royal Gwent Hospital in Newport and Abergavenny's Nevill Hall Hospital have been busy over the weekend with an increase in ice-related falls.
The M48 Severn Bridge has now re-opened with a speed restriction in place. Both directions had been shut since Friday.
One lane was also closed in both directions on the M4 second Severn Crossing.
And hazardous driving conditions are being reported on the M4 in both directions between junction 36 for Sarn and 38 for Margam.
The Penderyn, Maerdy, Bwlch and Rhigos roads all remain closed and are not expected to open until at least Monday.
Powys council says school transport will be operational on Monday while Rhondda Cynon Taf (RCT) council said it would make every effort to provide transport for pupils.
Parents are asked to check RCT's website for updates.
Councillor Andrew Morgan, cabinet member for frontline services, said: "Thanks to the dedicated teams who have been gritting our highways throughout the day and night on Friday and Saturday, the majority of main roads and bus routes are open.
"All efforts are now being made to clear side streets and ensure that secondary schools are open for exam week, next week."
First Cymru's bus services across south Wales were running to "near normal" timetables and most services in Bridgend and Maesteg were running following some disruption on Saturday.
Lloyds Coaches which serves Powys said all of its services were operating as normal.
First Great Western and Arriva Trains Wales services are operating normally, as is Cardiff Airport and ferry services from Pembrokeshire and Holyhead.
Meanwhile, Welsh Water has urged customers to make sure their pipes are protected from freezing in the cold weather.
Operations director Peter Perry said: "Our advice is take a few moments today and check to make sure any pipework - such as in attics, garages or running to outside taps - is adequately insulated."