It costs £74,000 a night to salt 7,000km of Northern Ireland’s roads in icy conditions — and it takes just three hours.
Roads Service staff swung into action recently as an unseasonal frost made driving conditions difficult — and will now remain on stand-by until spring.
But thanks to forewarning from the Met Office, they were ready for whatever the skies would bring and managed to keep main roads open during the early cold snap.
Paying tribute to his staff, Transport Minister Conor Murphy said they reacted well to the challenge and pledged that 288 personnel will be on standby every night to salt main roads until April.
“Roads Service’s winter gritting service is a massive logistical undertaking that involves salting approximately 7,000 km of roads, in just over three hours, across the north, at a cost of around £74,000 per night,” Mr Murphy said.
Engineers use ice sensors linked to 21 weather stations across Northern Ireland, installed in conjunction with the Met Office, as well as thermal mapping of all roads on the salted network. The Met Office uses information from the stations along with their own data to provide forecasts, which are transmitted to engineers’ computers. To keep motorists up to date with road conditions, information on salting activities is relayed electronically to the broadcast media.
“It is Roads Service’s policy to salt main through routes carrying more than 1,500 vehicles per day and other busy through routes carrying more than 1,000 vehicles per day where there are difficult circumstances, such as steep hills,” Mr Murphy said.
During long periods of heavy snowfall, key traffic routes are priorities, he said.
Once these main routes have been opened to traffic, Roads Service resources will be diverted to the quieter roads, especially in urban areas, and will continue until all roads are cleared.
In very deep snow, the 11 Roads Service snow blowers will be pressed into service — the latest of these can shift 1,600 tonnes of snow per hour.
Arrangements are also in place to enlist the help of contractors and farmers to clear roads.