Gov. John Hickenlooper on Wednesday vetoed a measure that would have required more public scrutiny of public-private road deals.

Senate Bill 197 was prompted after critics this year attacked the 50-year contract signed by the Colorado Department of Transportation with Plenary Roads Denver for the management and collection of tolls on U.S. 36 between Boulder and Denver.

They claimed the pact was done largely in secret and the length of the deal was too long.

Hickenlooper said Wednesday he supported the bill’s provisions that would have required more public scrutiny of further public-private partnerships. However, he said the bill also would have discouraged private firms from investing in any future road deals.

“We firmly believe that government should always strive to be transparent and accountable,” Hickenlooper wrote in a letter to the state Senate. However, the governor said, he could not support the measure because it “also inappropriately constrains the business terms of future P3 agreements.”

The bill would have required legislative approval of a variety of provisions of future public-private deals, including contract terms of more than 35 years and noncompete clauses.

“These constraints on business terms would create a chilling component on future transactions, making investors unlikely or unwilling to bid on Colorado projects due to the increased risks this process would generate,” Hickenlooper said.

Hickenlooper’s statement about the veto included a list of 45 business groups, communities and public officials who backed his move.

“While SB 197 contained many laudable transparency provisions,” said Tony Milo, executive director of the Colorado Contractors Association, “the bill also contained … provisions that limited the state’s flexibility to negotiate transportation financing deals, and could open the door to politicization of future transportation projects.”

In vetoing the measure, Hickenlooper signed an executive order meant to “improve transparency, accountability and openness relating to the Colorado Department of Transportation High-performance Transportation Enterprise.”

Hickenlooper has quashed a pair of measures this year. One would have limited what insurers require patients to pay for physical rehabilitation services, while the other concerned prohibiting the state from entering into an agreement for payments in lieu of taxes.

Spearheaded by state Sen. Matt Jones, D-Louisville, SB 197 also was intended to provide clear information on the costs and alternatives of such deals, require public participation at three key stages in the development of any deal, and promote more communication with state lawmakers.

“Those of us elected now will not be around when our children, grandchildren and great-grandchildren will have to live with these agreements,” said Jones, noting he respects Hickenlooper’s decision. “Taxpayers have a right to know. It’s disappointing when we seemingly trust Wall Street more than the people, and those they elect to represent them, to protect taxpayer dollars.”

Jones said he’s already working on a bill for next session that would address this issue.

State Rep. Mike Foote, D-Lafayette, said SB 197 was an attempt by Democrats and Republicans to protect the rights of taxpayers.

“Public-private partnerships must have the support of the people and their elected representatives,” Foote said. “Presenting a deal to the public and its representatives after completion won’t gain that support.”

Under the U.S. 36 contract, Plenary — a consortium of six companies — will finish the second phase of the $497 million U.S. 36 Managed Lanes project and be responsible for the upkeep for the entire corridor, including ice and snow removal, until 2063.

Kurtis Lee: 303-954-1655, klee@denverpost.com or twitter.com/kurtisalee