Cost estimates for the completion of the final leg of the Zoo Interchange project are climbing in the wake of lawmakers’ decision to postpone that project until after the state’s current two-year budget period.

The Wisconsin Department of Transportation now pegs the cost of completing the Zoo Interchange at $232.6 million, which is up from an estimate of $202.2 million issued in 2017. Critics had warned that a delay could drive up the project’s costs when Republicans were busy adopting a provision barring work on the north leg of the Zoo Interchange during the 2017-2019 biennium.

Michael Pyritz, WisDOT spokesman, said in an email that the higher estimates are the result of inflation and design-cost predictions. He noted that the project is now scheduled to be let in 2021, rather than 2018. He cautioned, however, that the project’s final cost won’t be known until the state receives bids for the work.

“Until the bids are received it is premature to make a statement saying it is higher or lower than estimated,” he wrote.

Most of WisDOT’s increased estimate for the Zoo Interchange is the result of $21.6 million worth of contingency costs. Without those, the agency estimates that the project would cost $211 million, $7.7 million of which would result from expected inflation and $3.1 million from design costs. Pyritz declined to provide details about the cost estimate, saying that such information could influence bid results. He said the latest estimate takes into account seven components of the Zoo Interchange’s north leg.

Craig Thompson, executive director of the Transportation Development Association of Wisconsin, said it’s little surprise that the cost of completing the Zoo Interchange would increase following a two-year delay. There’s still no clear plan for how the state intends to complete the project, either.

“Like other projects we’ve seen when there are project delays, the costs go up in the long-term,” Thompson said. “If they they punt again this session, I think we should all expect the price to go up again.”