More than 100 bus passengers were stuck in Barton, Oxford, for more an hour as traffic leading up to the roadwork-hit Headington roundabout ground to a halt.

Seven buses were trapped on the estate between 7.30am and 8.30am.

Road improvement work to create a new road to carry A40 traffic through the middle of the roundabout has caused heavy tailbacks since it started in April.

However, the delays became much longer from the beginning of last week as the roundabout and both the northern bypass and London Road approaches to it were reduced to one lane.

Highways chiefs say the problem was compounded by an accident on the ring road between the A4074 and the B480 junctions and the closure of a minor road near Islip.

But that did little to ease the frustration of hundreds of commuters who were forced to sit in traffic on the Barton estate and Bayswater Road in the rush hour on Wednesday morning.

Oxford Bus Company said at one point, five of its buses were stuck on the estate for between half an hour and an hour and a half.

At the same time, two Stagecoach buses were stuck in traffic trying to get on to Bayswater Road for between 30 minutes and 50 minutes.

Oxford Bus Company spokesman Phil Ashworth said: "The heavy traffic had a definite effect on our bus services. It has been an issue for some time, but on that morning, it was unprecedented.

"We are very sorry that people are being delayed but we know that our customers understand that it is a problem not of our making."

Chris Childs, of Stagecoach, added: "It did not ease up all day and the next two weeks are going to be the worst of the entire road improvement scheme."

Phil Griffiths, who lives in Colwell Drive, Green Ridges, said it took him an hour and a quarter to complete what is normally a five-minute journey from his home to the Headington roundabout.

He said: "I was sitting in traffic for so long. No-one was giving way, it was absolutely gridlocked and then when I got to the roundabout, there were two guys standing on shovels picking their noses.

"The residents of Barton and Green Ridges and everyone trying to access the road are being penalised by the roundabout.

"If the residents of Barton and Green Ridges and people who have to access Bayswater Road have to wear this for another 18 weeks, then the county council has to offer us some kind of diversionary routes."

Oxfordshire County Council spokesman Paul Smith said the roadworks were due to continue until the beginning of December.

But the northern bypass and A40 approaches to the roundabout were due to be fully open again by today.

County Council principal engineer Colin Baird said: "From todaymonday the eastern bypass entrance will be down to one lane and this will cause delays and we'll get that done as quickly as we can, hopefully less than a week.

"Traffic on Friday was significantly more free flowing after the one lane restrictions of earlier in the week were removed.

"They were removed because yet another phase of this job has been completed.

"The messages remain the same from us.

"Please use other routes if at all possible.

"We can't do a job as big as this without causing disruption. But the end is now close."