Thu, 08 Dec 2011 07:23 CST
They said the people could be putting themselves in "considerable danger by travelling".
Association of Chief Police Officers of Scotland (Acpos) told STV News that travel should be avoided in the between noon and 7pm in the west and 2pm and 9pm and the Central and Lothian and Borders area.
The Met Office warned of severe weather and gale-force winds on Thursday with councils deciding to close hundreds of schools. Gusts reached 130mph over Aonach Mor, near Ben Nevis, and 102mph over Glen Ogle in the Trossachs.
Red warnings - the higest level of Met Office alerts - were issued for wind in the Strathclyde, central belt, Tayside, Lothians and Borders areas.
Speaking for Acpos, Assistant Chief Constable Allan Moffat from Central Scotland Police said: "The advice for motorists across the central belt of Scotland is to avoid travel as the severe weather moves across the country from west to east, starting around noon on the west side of the country.
"It is expected that the impact of the weather will affect the east side of the country from 2pm onwards. This advice to avoid travel is not given lightly but is based on the clearest information yet from weather forecasters that there will be high winds with gusts of up to 90mph.
"The time frame for these exceptional conditions is between noon and 7pm and I am being given clear information that a wide area of Scotland will be affected. People could be putting themselves at considerable risk by travelling in these conditions.
"We are receiving continuous updates from the Met Office advising of severe weather which will impact across Scotland.
"The forecast for such extreme weather means that it is probable that we will need to close some or all of the major bridges. This will inevitably cause disruption on major routes and have an impact on other road networks.
"The predicted impact of the wind is such that it may cause structural damage and is a specific danger to high sided road vehicles.
"I would ask the public to pay close attention to weather and road updates and act accordingly to the advice given.
"I recognise that this is a significant statement however it is based upon the premise of ensuring public safety and minimising the risk to road users in the affected areas."
Chief Inspector Stewart Carle, of Strathclyde Police's road policing unit, said that all travel on the roads in the region was being advised against.
He told STV News: "We are advising against all travel on the roads due to the disruption that will be caused by the severe weather, such as fallen trees and flooding.
"I have every available patrol car out there monitoring key routes such as M8 at the Kingston Bridge and the M74 will be watched.
"We are advising to avoid travel and stay in and tune in for updates on the situation."
In North Ayrshire, a school bus was blown over on the A737 near Dalry at around 10am. There were no passengers on board at the time, while the driver was uninjured. Strathclyde Police closed the road in both directions as they tried to move the vehicles.
The Scottish Government issued guidance that schools across the west, central and Southern Scotland should either not open or close early and those in the east close around lunchtime.
Deputy First Minister Nicola Sturgeon said: "We can expect very severe gales, at wind speeds not seen for many years, across large parts of western, central and southern Scotland throughout Thursday.
"On the basis of the earlier 'Red Warning' from the Met Office, some Councils had already taken the precaution of closing schools early to make sure that parents can safely collect children before the most dangerous weather and travel conditions arrive.
"In light of the latest forecast, and in particular the timings which suggest the severe weather affecting the west-central part of the country earlier than originally anticipated, some of these closure timings may have to change.
"Having considered the updated information received from the Met Office tonight, the police have advised that there is a probability that they will change their travel advice in the coming hours from warning about a high risk of disruption to a position where they will advise drivers to avoid travelling on the roads in the affected areas.
"Given that many drivers and parents will need clarity before leaving home in the morning, and on the basis of the very latest advice from the Met Office and ACPOS, we are advising Councils in all the affected areas to give parents and teachers the earliest possible notice of their intention to either not open schools at all in the west or to close at noon in the east.
"The decision is a matter for individual authorities but the warnings are of the highest level of seriousness and we are clear that safety has to be the paramount issue. Parents should check locally through websites, local radio and with their schools to find out the specific situation with their own schools.
"More generally, it is clear that there will be widespread disruption across the transport network tomorrow, and the real possibility that key bridges will be closed for a time to all traffic. As well as possible bridge closures the authorities are preparing to deal with blown over vehicles and trees.
"All commuters are advised that if they can adjust their working pattern to reflect the latest weather and travel advice or work from home that would be a very sensible step to help avoid possible traffic disruption. The authorities are all working hard to keep Scotland moving."
The Scottish Environmental Protection Agency has issued 11 flood alerts for locations across Scotland. The areas affected are: Argyll and Bute, Ayrshire and Arran, Caithness and Sutherland, Central, Dumfries and Galloway, Easter Ross and Great Glen, Findhorn Nairn Moray and Speyside, Borders, Skye and Lochaber, Tayside, and West Central Scotland. So far, no flood warnings or severe flood warnings have been issued.
The Forth Road Bridge is to close for four hours between 3pm and 7pm on Thursday because of the stormy weather. At around 10.30am the Erskine Bridge was closed to all vehicles after restrictions had been put in place earlier.
In Glasgow, all schools will be closed on Thursday but the council said staff should report to work as normal. East Ayrshire also announced a complete closure of its schools. South Ayrshire said all its schools would be closed too. North Lanarkshire changed its advice overnight and said all its schools would close. South Lanarkshire also said its schools would not open.
While in Edinburgh, schools will shut at noon. Fife schools will close at lunchtime, as will Midlothian schools. West Lothian schools will close at noon.
Renfrewshire Council announced all schools were closing at 1pm on Thurday after the alert. All special schools, including Hollybush Pre-five Centre, will be closed all day.
Historic Scotland confirmed the closure Edinburgh Castle, Stirling Castle, Dunfermline Palace and Linlithgow Palace due to the severe weather. Iona Abbey, Caelaverock, St Andrews Castle and St Andrews Cathedral were also closed.
In Glasgow, organisers of the festive Glasgow on Ice event in George Square have confirmed it will close as the gale force winds are expected to hit the city.
All classes at the University of Strathclyde are cancelled, and while the University of Glasgow will remain open, all classes and exams are cancelled.
Stirling Council has also taken the decision to close all primary schools, nurseries and high schools at 12.30pm on Thursday. East Renfrewshire also said its schools would close from 1pm on Thursday.
North Ayrshire issued a recomendation for parents to "keep children at home" and said its schools would be closing early. Scottish Borders Council said all its schools would close at lunchtime.
The warnings have been described as "highly unusual" by Transport Scotland, which is urging people to pay attention to police travel warnings. Police advise that conditions for travel between 3pm and 6pm on Thursday are likely to be extremely poor and significant delays should be expected.
The Scottish Government said the wind could lead to all main road bridges being closed and will have a severe impact on Thursday's rush hour, while disruption to power supplies and property is also a strong possibility.
ScotRail said speed restrictions of 50mph could be put in place tomorrow on trains travelling after 10am.
Steve Montgomery, the train operator's managing director, said: "We will constantly review weather forecasts and respond accordingly. Our aim is to ensure as robust a service as possible.
"The forecasts are that the peak of the high winds will be in the afternoon and early evening. If that happens, it would be a sensible step to allow more time for journeys, to keep checking our website and where possible leave work earlier to avoid rush-hour."
Transport Minister Keith Brown said: "Tomorrow looks set to be a major challenge for our transport system, commuters and the public. I can assure them that a lot of work is already underway to ensure Scotland is prepared for any likely transport disruption caused by severe winds.
"We are in regular contact with the Met Office, the police, operating companies, power suppliers and other authorities and agencies to ensure everything that can be done is being done.
"Potentially many of our main road bridges could be closed at some point tomorrow afternoon. According to the Met Office the worst period will be from 3pm to 6pm and they are confident that wind speeds will exceed 75mph. They have issued a red alert, which suggest speeds could even exceed 90mph. As well as possible bridge closures, we need to prepare for blown over vehicles and trees."
Assistant Chief Constable Allan Moffat, on behalf of the Association of Chief Police Officers, said: "With weather conditions expected to change dramatically over the next 24 hours, I would ask motorists to plan ahead for any journeys by checking travel updates through television, radio and internet sites before they set off.
"If the weather is as severe as currently being predicted, then there will be a significant impact on the roads network with a high risk of disruption.
"As with any conditions that can make driving and travel hazardous, I would ask that people drive with caution, plan ahead to ensure routes are open and safe, and be prepared for any delays or disruption that could affect their journey."
STV weather presenter Sean Batty added: "A storm system will pass over Scotland on Thursday bringing heavy rain and very strong winds.
"Winds will be strong enough across western southern and central areas, in particular, to cause structural damage.
"The winds may exceed 75mph in places and that could even include parts of the central belt, where it could be particularly disruptive in the heavily populated areas."
On Wednesday the A939 Cock Bridge to Tomintoul road, the B974 Banchory to Fettercairn road and the A93 between Glenshee and Braemar were all shut due to heavy snow.
A drop in temperatures in Dumfries and Galloway in southern Scotland caused icy road conditions in some areas. The A75 was forced to close at Barskeoch, west of Newton Stewart, due to a road smash involving a lorry and a 4x4 dragging a trailer containing 30 sheep.