Large parts of Aberdeen almost ground to a standstill last night after one of the main bridges over the River Don was closed by a gas leak.
Drivers had to endure a day of misery when the Persley Bridge carrying the busy A90 in both directions was forced to shut.
And more disruption is likely today as the bridge, which crosses the Don near the Haudagain roundabout, is expected to remain closed until lunchtime after emergency repairs to a gas mains.
A police spokesman said last night: “All traffic entering the city, north and south, was affected throughout the day with traffic brought to a near standstill several times.
“Basically, all the traffic which uses one of two main Don crossings was filtering through to use the one remaining crossing, and this was always going to lead to major issues.”
For around 14 hours, long queues of traffic stretched on numerous roads as frustrated commuters sought out alternative routes well into the evening.
From 7am until 9pm, lengthy tailbacks built up, particularly in the north of the city as engineers worked flat out to repair the leak.
There had been disruption after Scotia Gas Network (SGN) started work near the bridge at 6.30pm on Tuesday.
Initially, traffic was allowed across the bridge controlled by temporary traffic lights, but after the leak had been noticed by a member of the public, the road was completely closed at 11.45pm.
The worst affected areas were King Street, Beach Esplanade, Great Northern Road, North Anderson Drive, and a warren of streets connected to them.
Tailbacks lasted until after 9pm, before traffic started to ease off, but the knock-on effect was widespread.
A SGN spokeswoman said: “In order to manoeuvre our equipment and carry out our work it has been necessary to close the road in both directions.”
The road works caused huge tailbacks during peak times for traffic yesterday.
Pedestrians were still able to access the bridge, but motorists faced a detour via the A956 Ellon to King Street Road, Great Northern Road and St Machar Drive.
Diversions were also put in place at Scotstown Road and Whitestripes Road.
The SGN spokeswoman added: “We apologise for inconvenience to motorists. We’re very conscious that it’s a really busy road.”
SGN was first made aware of a gas leak in the area on April 7 after a member of the public reported a smell at the Persley Bridge. After making the mains line safe on the day, bosses arranged to carry out permanent repairs this week.
A spokeswoman for Bear Scotland – which manages Mugiemoss Road – said: “We liaised closely with Police Scotland and Aberdeen City Council this morning to close the road and ensure that a suitable diversion route was put in place.”
Bridge of Don councillor Willie Young said “unforeseen circumstances” had conspired to cause the situation.
“It’s very, very unlucky that there’s a gas leak, and it’s lucky that it’s in the school holidays,” he said.
“When it’s human life versus traffic congestion, human life comes first. We have to make sure that the public are not at risk.”
Mr Young also denied suggestions that opening bus lanes on alternative routes would have helped to ease traffic jams.
He said: “The difficulty with the bus lanes opening up is we need the bus lanes to deal with the traffic.
SGN said it aimed to reopen the bridge by lunchtime today, having completed the gas repairs yesterday afternoon.