The M8 through Glasgow city centre has been branded the worst commuter route in Britain in a new survey.

Leading traffic information service, Keepmoving, conducted a study to find the UK's most congested road around major cities such as London, Birmingham, Manchester and Glasgow.

In order to calculate the percentage of time that motorists were stuck in a traffic jam, they measured the speed of vehicles at three minute intervals between 7:30am and 8:30am and between 5pm and 6pm on all motorways and trunk roads near the four cities.

The figures they collated during April revealed that travellers in and around Glasgow were stuck in a queue and had to cut their speed more times than anywhere else around the country.

Glasgow's top five hotspots are all on stretches of road on the M8 Eastbound, between Junctions 16 and 20, where delays are almost inevitable and are most acute at Junction 16 at Cowcaddens where there was an 85% chance of being stuck in a queue.

At the Kingston Bridge (J20) the chance of delays were 81%, at St George's Cross (J17) it was 79%, and at Charing Cross (J18) and Anderston Cross (J19) the figure was 78%.

Alex Petrie, product director of Keepmoving, said: "Commuter congestion in London and the South-east is still a major problem but increasingly roads in the Midlands, North-west of England and Scotland feature among the worst in Britain."

Neil Greig, of the IAM Motoring Trust in Scotland, said: "I am not surprised at the results of the survey. Between Charing Cross and the Kingston Bridge you have all the traffic being filtered into two lanes which is always going to cause problems.

"The only real solution to ease traffic problems in that area is to take traffic away. Because of that it is important the stretch of road which will be the M74 extension is opened as soon as possible.

"That will allow traffic from Ayrshire and Renfrewshire to get across to Edinburgh without having to go over the Clyde or through Glasgow which will greatly ease congestion."

Transport Scotland, the Scottish Executive's roads monitor, said it realised the importance of the M8 to the Scottish transport network.

A spokesman said: "We recognise the national importance of the M8 and are commited to a multi-million pound maintanence programme.

"In addition to the major impact the M74 completion project will have on M8 congestion, we are also committed to delivering a £180m upgrade of the A8 trunk road between Baillieston and Newhouse to motorway standard. This will provide a continuous motorway link between Glasgow and Edinburgh by 2011." The spokesman added that the five-mile-long M74 extension was currently at the tendering stage and it was expected to cost somewhere between £375m and £500m.

The extension will be a three-lane motorway which will start at the Fullarton Road junction near Carmyle to the M8 motorway just west of the Kingston Bridge. Expected to be completed by the end of 2010, it is designed to improve access along the entire Clyde corridor and make it easier for people to catch flight connections from Glasgow Airport.