Final sections of the guided bus route are laid by BAM Nuttall Ltd
The final section of track has been laid on the world's longest guided busway.
Construction on the route, which includes 13.3 miles (21.5km) of guided track, began in 2006 and was due for completion in February 2009.
Bob Menzies is Cambridgeshire County Council's head of busway delivery.
He said: "Although it is good news the final piece of the track has been laid, no one is celebrating as BAM Nuttall have still not completed the job."
The contract for Cambridgeshire's guided busway was awarded to BAM Nuttall Ltd in July 2006.
However, the company has failed to deliver the finished product and a number of major defects along the northern section of the route remain.
The county council was given assurances in April 2010 that these would be rectified.
The final section of track may have been laid by BAM Nuttall Ltd, but this is far from being the end of the road for the much-maligned guided busway.
The busway contractor says that it will complete work in January 2011
"All Cambridgeshire residents want to see is the contractors complete the work so buses can finally start running," said Bob Menzies.
"BAM Nuttall are already 18 months late delivering the project.
"As a result they have been deducted in excess of £8 million in damages so far and we will continue to deduct almost £14,000 a day until the job is done."
Meanwhile, the scheme has come in for criticism from Fiona Whelan, leader of the Liberal Democrats and councillor for Madingley.
She claimed that funds put aside to pay for the inevitable legal battle between the council and BAM Nuttall Ltd could have been spent on improvements to road safety.
Ms Whelan spoke to BBC Radio Cambridgeshire and said: "The council has been cutting back on the amount of money it's been putting into road safety measures.
"In particular there is £1m left this year because that's been taken out of the local transport fund and it's going towards legal fees for the guided bus. So the council is spending a lot less on road safety programmes at the moment."
Councillor Mac Maguire is the cabinet member for highways at Cambridgeshire County Council.
GUIDED BUS DEFECTS
River Great Ouse viaduct expansion joints
St Ives Park and Ride surface ponding
Maintenance track flooding
Guideway shallow foundations
Thermal expansion gaps between the guideway beams
Rubber tyre infill between the guideway beams
He said: "We are having to make allowances for the possible additional costs that may be incurred by the guided bus, but it's not being taken from the safety budget.
"Liberal Democrat councillors are misleading residents by suggesting £1 million is being taken out of the budget for road safety improvements.
"In fact over £1 million will be spent on safety improvements this year - slightly more than was spent last year."
He added: "We have been clear all along that we are setting aside from the transport budget £1 million a year as a provision against potentially increased busway costs.
"This is exactly what any prudent authority would do.
"Should the money set aside not be required in future years then it will be returned to the transport pot.
"Our current forecast is that the cost of building the busway for the council will be just over the original budget of £116m, and if that is the case at the end of the project the money being set to one side will not be required for the scheme."
BAM Nuttall's current construction schedule states that the guided busway will be completed in mid-January 2011.
The company has refused to comment on the county council's criticisms due to "contractual obligations"