Conditions on Scotland's roads remain 'challenging'
Drivers are being warned that conditions in parts of Scotland remain "challenging".
Motorists have again been warned not to drive unless it is necessary, with drifting snow on several roads.
The vast majority of ScotRail trains are still cancelled in the central belt, but a limited number started to run earlier.
They included a half-hourly service between Edinburgh and Glasgow, via Falkirk High.
ScotRail Alliance managing director Alex Hynes told BBC Scotland: "The worst of the weather is over and our task is now to reopen Scotland's railway network.
"We're working night and day now, line by line, to inspect each line of route to make sure it's safe to run."
He said the company was introducing a limited service on some routes.
He added: "We're expanding the hours of operation and over the course of the coming hours and days we'll be opening more and more of Scotland's railway network."
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Network Rail said drifting snow had made the safe reinstatement of routes "really challenging".
It added: "It is a fluid situation and we cannot give specific times at this point on when lines will re-open or if/when services will run".
Virgin Trains said no trains were running between Scotland and England on either the east coast or west coast lines.
Most flights were again cancelled at airports including Glasgow, Edinburgh and Aberdeen, with passengers urged to check with their airline before travelling to the airport. However, Edinburgh Airport has since reopened.
First Glasgow was running some bus services in the city earlier, while Lothian Buses was planning to introduce a Sunday service. A reduced tram service was also running.
Some Scottish CityLink coaches were running, but the firm said it could not guarantee travel north of Perth due to dangerous driving conditions.
Most schools remained closed across the country.
An amber Met Office warning expired at 10:00 but a yellow warning remains in place, mainly in eastern areas, with extreme cold weather expected to last through the weekend and into next week.
Transport Scotland had 200 gritters out overnight trying to keep roads clear, and there was no repeat of the scenes from the previous night when about 1,000 vehicles were trapped on the M80 and surrounding roads for up to 18 hours.
But many roads have been hit by drifting snow, with police and gritters attempting to free about 30 vehicles stuck on the A92 north of Inverbervie in Aberdeenshire.
One person was hurt after a multi-vehicle collision on the A90 near Tealing in Angus which closed the southbound carriageway.
A woman who went into labour in the village of Balgedie, near Kinross, was helped by farmers and off-duty midwives after a call for help was made on social media.
Emma Niven whose husband Rob was one of the first to get involved with his tractor spoke to the BBC's John Beattie radio programme.
She said: "It's just been the most magical morning. An emergency message went out on Facebook looking for midwives for our neighbour who was in the late stages of labour and was stuck.
"We just couldn't get her out and nobody could get to her so we got the tractors out and negotiated a couple of midwives and brought them to her just in time at a critical stage where the baby's head was actually stuck.
"So all has turned out well but oh my goodness what a morning."
In a Facebook post, the new mum said her baby boy was "safe and sound after a terrifying home birth which was only possible thanks to you all".
Police and mountain rescue teams searching for a 51-year-old woman who went missing in the Ochil Hills have found a body.
Alison Fox, from Alloa, went missing during a walk in the hills behind Menstrie on Thursday afternoon.
A small number of drivers were stuck overnight at a level crossing on the B9175 near Tain in Easter Ross in the Highlands, where snow drifts were said to be up to 5ft deep in the area. A large part of the area is said to have been cut off by snow.
Emergency services also had to clear 8ft snowdrifts on the M9 near Stirling overnight to rescue a jacknifed HGV.
South Lanarkshire Council warned of drifts up to 10ft deep on exposed routes, with "extremely dangerous" conditions in some areas.
BBC weather forecasters said the latest recordings show depths of 50cm (2ft) in Drumalbin near Lanark in South Lanarkshire - although elsewhere depths could be even higher.
Transport Minister Humza Yousaf stressed that it would take time to make routes safe despite the amber warning being lifted, and urged people to be patient.
Meanwhile, military 4x4 vehicles were drafted in to help essential staff reach Edinburgh hospitals.
Soldiers were running the transport service for the Royal Infirmary of Edinburgh and the Western General hospitals.
Police Scotland and the Scottish Fire and Rescue Service have also supplied vehicles for the operation.
Health Secretary Shona Robison said the Edinburgh transport operation followed a request from NHS Lothian.
The MoD said it was now also helping NHS staff get to work in the Fife and Tayside areas, using up to 30 vehicles and 60 personnel.
They will mainly cover NHS shift change periods.
And Power company SP Energy Networks has been providing 4x4 vehicles to ferry NHS staff to their work in central and southern Scotland.
Where to find the latest weather and travel information
Up to date forecasts can be found on the BBC Weather website
In times of severe disruption you can also follow the BBC Scotland severe weather Twitter list of key sources.
We have compiled a list of where you can find information on school closures.
Below are a number of other traffic information sources.
- Traffic Scotland
- Transport Scotland
- Ready Scotland
- National Rail Enquiries
- Traveline Scotland
- Network Rail
What the weather warning colours mean
- Yellow: Severe weather expected. Yellow means you should plan ahead thinking about possible travel delays, or the disruption of your day-to-day activities.
- Amber: Be prepared for disruption. There is an increased likelihood of bad weather affecting you, which could potentially disrupt your plans and possibly cause travel delays, road and rail closures, interruption to power and the potential risk to life and property.
- Red: Extreme weather is expected. Red means you should take action now to keep yourself and others safe from the impact of the weather. Widespread damage, travel and power disruption and risk to life is likely. You must avoid dangerous areas and follow the advice of the emergency services and local authorities.
You can also contact us in the following ways: