Drivers using the Queensferry Crossing have been warned they could face 'chaos' this winter if car windscreens are hit again by falling ice from the bridge's cables.
Scottish Conservative Lothian MSP Miles Briggs highlighted an incident whereby falling ice resulted in three car windscreens being smashed on March 16th this year, prompting an investigation.
Mr Briggs says he is alarmed that the Scottish Government is yet to fit ice sensors, which would alert engineers to the hazard of ice build up on the cables.
But a Transport Scotland spokesman said the sensors will be installed "as soon as possible," stressing ice build-up of this kind has not been an issue on other cable-stayed bridges like the Erskine and Kessock and has been "very rare" in the UK.
If there is a danger of ice falling, lanes could be closed on the bridge to protect motorists.
Mr Briggs said: "The build up of ice and the risk to motorists using the bridge is a hazard that should have been considered before the bridge was opened to traffic.
"With winter having arrived and temperature set to plummet it is urgent that these sensors are installed to detect the build up of ice.
"In other countries, such as Canada, they have encountered the same problem as the Queensferry Crossing and they have been able to find a solution.
“Solid blocks of ice falling on motorists cars is hugely dangerous and all necessary steps must be taken to ensure the safety of motorists using the Queensferry Crossing."
Other structures in the UK have been affected by ice in the past and the Forth Road Bridge was once briefly closed to traffic to allow for ice to be cleared from cables.
Road bridges over the Severn in south-west England had to be closed ten years ago after ice fell from gantries on the Second Severn Crossing.
The Queensferry Crossing's structural health monitoring system is expected to be fully operational later this year. This system monitors the entire bridge structure and how it responds to variables such as weather conditions - wind speed, direction and temperature - and loading. The ice sensors are different to this and purely just for the purpose of monitoring ice build up.
The Port Mann bridge in Canada uses a collar system which is said to be one of the most successful systems in the world, however it is not fool-proof. Snowfalls during December 2016 resulted in approximately 50 insurance claims from falling ice and snow.
The Transport Scotland spokesman said: "Ice build-up of this kind has not been an issue on the other Scottish cable-stayed bridges, Erskine and Kessock, and historically has been very rare in the UK. Ice sensors will be installed as soon as possible
"In the event of icy conditions in the future, the bridge will be closely monitored, informed by our investigations into last year’s ice accumulation, using data from weather stations and public safety will be prioritised. We continue to explore international best-practice and possible methods of preventing ice build-up in the future.
"Close to 80,000 vehicles have been using the Queensferry Crossing every day since 2017. The new wind barriers have undoubtedly delivered a more resilient crossing during severe weather. It has remained open to high-sided vehicles and HGVs on over 30 occasions when the Forth Road Bridge would have been closed or restricted."