Transportation took center stage in the Colorado governor’s race Thursday as a commission appointed by Gov. Jared Polis signed off on a climate-minded reordering of major project priorities, while his Republican challenger laid out a vision that heavily favors expanding road capacity.

The state Transportation Commission met in the morning to approve an updated 10-year project list that tamps down the state’s plans to widen highways — and speeds up plans for rapid-bus corridors in metro Denver — as a way to reduce greenhouse gas emissions. Gone are plans to widen Interstate 25 through central Denver and C-470 through Lakewood, though some other highway expansions remain in the queue.

Just minutes before the vote, Republican Heidi Ganahl unveiled her own transportation plan at a park near the Colorado Department of Transportation’s Denver headquarters. She called for supercharging transportation legislation championed by Polis and other Democrats last year, nearly doubling its $5.4 billion in spending over the next decade to $10 billion.

To do that, Ganahl would rely on billions of dollars in state budget set-asides and new public-private partnerships. And rather than outright rejecting the new array of fees on gas purchases, deliveries and other items that last year’s Senate Bill 260 set in motion — and which conservatives are challenging in court — she says she’d simply ask voters to approve them as taxes, likely in the 2024 election. They’d come with a 10-year sunset.

“Driving gives you the freedom to go where you want, when you want,” said Ganahl, joined by Republican state lawmakers and other supporters. “Right now, inside this building, they’re attacking that freedom. All this leads us to a need for a different plan, a common-sense solution that reduces carbon emissions by alleviating traffic and helping Coloradans travel our state safely and on time.”

Beyond that, she did little to detail how her plan would address pollution, though she said new toll lanes on Interstate 25 and other highways would help buses travel faster, too, and added that she’d support transit investments when they made sense. But she criticized the Polis administration’s use of significant money for transit initiatives, electric vehicle-supporting efforts and other non-road priorities.

That multimodal focus has animated the recent changes to the Polis administration’s 10-year priority project list, approved unanimously by the commission. In coming weeks, the boards of transportation planning organizations for metro Denver and the north Front Range region, which includes Greeley and Fort Collins, will consider climate-minded updates to their long-range plans as they also face a state mandate to meet greenhouse gas reduction targets.

The Denver Regional Council of Government’s 2050 plan update would shift $900 million from road-widening projects to bus rapid transit projects and other travel options.

Instead of a capacity expansion, the I-25 central corridor in Denver, the state’s busiest highway stretch, would be due for safety upgrades and interchange improvements north of Alameda Avenue under both the CDOT and DRCOG plans.

Environmental, community and transit advocates in Denver supported that change.

“Removing the widening of I-25 through central Denver is a great beginning,” said John Riecke, a transit and bike advocate who lives in the I-25-bordering Sun Valley neighborhood. “Once you need 12 lanes for a highway, what you actually need is a bus, what you actually need is transit.”

For his part, Polis after the vote played up the extensive improvements to roads and bridges that are still part of CDOT’s plan.

“We are taking bold action to improve our infrastructure, roads, and bridges while saving people time and money,”  he said in a CDOT news release.

On Wednesday, ahead of the project list vote, CDOT announced to cheers from northern Front Range advocates that it would pull the trigger on the next North I-25 project. Along a 7-mile segment between Colorado 66 and Colorado 56, it will add an express lane in each direction where I-25 currently has two lanes each way. That’s possible, CDOT officials say, because toll revenue will be sufficient to close a funding gap on the $350 million project.

Plans to widen Interstate 270 in the northeast metro area and I-70 in the mountains at Floyd Hill also will likely incorporate tolled express lanes — an element Ganahl’s plan embraces in a big way.

She sees them as key to attracting deals with private partners to help get more projects financed and built. Her plan calls for such partnerships to raise $3 billion over a decade, with $3.5 billion coming from the SB-260 fees — if voters agree to convert them to taxes — and an equal amount from state general fund transfers, or roughly $350 million a year.

At the same time, she’s called to eliminate the state income tax, which would require sizable budget cuts.

“I’m confident that the General Assembly can find that room in the existing budget, let alone as we work to shrink the size of government and bureaucracy and find waste and fraud,” Ganahl said. She noted that $350 million is roughly 3% of the current budget’s general fund.

She also wants to cut the 22-cent state gas tax, which goes toward road and transportation projects, by half. That would put her in the odd position of cutting that tax and then, with her plan to place the SB-260 fees on the ballot, asking voters to allow that tax to rise higher over time. SB-260’s fee roster has it starting at 2 cents per gallon next year and rising to 8 cents by mid-2028.

Ganahl released a list of corridors she’d target money to, including $3 billion to run toll lanes on I-25 all the way from Castle Rock to Fort Collins, along with paired bus transit investments; $1 billion for the I-70 mountain corridor; $1 billion for a statewide rural paving program; and $250 million for the U.S. 85 corridor in Adams and Weld counties.