Original estimates saw £4.3m set aside for the multi-lane one-way system, off Dodworth Road, but a further £3.053m was granted in December 2020.
According to a report - which will be discussed by ruling cabinet members on Wednesday - a further £498,000 is set to be allocated due to ‘steel market volatility and construction costs’.
The road - commissioned by Barnsley Council in a bid to reduce tailbacks for town centre-bound traffic from junction 37 of the M1 - is partially open but was expected to be fully completed by March.
“In November 2021, following a robust procurement exercise, cabinet approved the award of the Penny Pie Park civils works contract,” the report said.
“It has not yet been executed due to a number of mining risk uncertainties raised by Network Rail - these have now been addressed following ground condition surveys and further testing.
“The results have now been accepted and signed off by Network Rail, and we are now able to approve the contract with the preferred contractor.
“A reviewed tender price - in line with clauses in the contract - and a delivery programme has been provided by the contractor and their sub-contractors.
“Additional resources of £498,000 have been approved to support the delivery of the overall scheme.
“Volatility in the steel market and construction costs mean that the contract prices are changing almost daily, meaning that the preferred contractor and sub-contractor are unable to guarantee to hold their prices.
“The council therefore moved quickly to ensure the delivery of the project and also avoid any delays which would impact on the current delivery programme agreed with Network Rail./
“Governance and value for money are at the core of everything the council delivers.
“We continue to stringently review all cost and income projections associated with the development to make sure that value for money is demonstrated and achieved.”
Although a completion date has not been set, the council revealed the project is in its final stages and a footbridge - which will provide a link between Dodworth and Pogmoor over the railway line - will be erected.
Kathy McArdle, service director for regeneration and culture, told the Chronicle: “The scheme is in the final phase, with a partial opening of the gyratory now in place.
“The full gyratory will be opened in phases that will coincide with the switching on of the new traffic controls, which we are carefully planning in terms of traffic management.
“The next stage of the plans include the building of a new foot and cycle bridge for the park, to connect the two green spaces divided by the Sheffield to Huddersfield railway line.
“The enhancements to the park area, which include tree planting, landscaping, new footpaths and new play equipment, have gone well while taking into account some interruptions due to the weather since the start of the year.
“We are looking forward to the completion of the project, which is vital to support our future business and housing growth plans, and improve access to our new town centre.”
Coun Peter Fielding said he was particularly unhappy about how the decision to give extra funding was made.
“It was made an urgent matter, meaning there was no calling period which would allow a proper scrutiny process - I’ll be asking questions about the extra costs and when this decision was made.
“If it was some time ago, it means they definitely had chance to go through the proper channels.
“I want to make it clear that I’m very much in support of the footbridge, and it was first suggested when the Horizon school was built as a valuable addition.
“My understanding is the delays have been caused because of difficult ground conditions, and they had this same problem with the one-way gyratory system.
“It’s a former landfill site, so I’m sure they knew perfectly well about the issues before starting work on it.”