The cost of building Bristol's MetroBus network has gone up by almost 5% in a year to £230m, the city council has revealed.
Initially estimated to cost £190m in 2015, the bill has risen a further £10m from £220m since November, a report to cabinet says.
Contractor costs, design changes and contaminated land disposal are cited as key reasons for the rise.
Extra borrowing and "additional parking income" will make up the shortfall.
The report says the overall cost for the controversial public transport scheme has gone up to £230.496m from £220m since November 2016.
The majority of the overspend relates to the Ashton Vale to Temple Meads section - one of three parts of the overall system.
Bristol will have to find £6.8m to pay for its share of the overspend, but the report says it will need to "stop certain schemes" and redirect funding/borrowing from other projects.
South Gloucestershire and North Somerset councils will pay £3.47m and £0.46m respectively for their share.
The report adds council officials will ensure "cost pressures for the programme are scrutinised and challenged and the programme is delivered as economically beneficial as possible".
The latest cost hike comes after neighbouring South Gloucestershire Council said its highways maintenance budget will need to be raided for 10 years to pay for cost overruns on the Metrobus's North Fringe to Hengrove route.
Extra costs including the removal of protesters from trees in Stapleton Road allotments and additional security measures were blamed for the overall bill rising to £216m last year.
- 20 June 2017
- 26 October 2016
- 21 October 2016
- 24 February 2015