A passenger rail that would cart passengers up and down the Front Range remains a long way off.

Construction likely wouldn’t begin on the project for at least seven years – and only if a host of other funding and planning components come together, according to proposal a state commission submitted to the Colorado General Assembly on Friday.

The commission, appointed in July to explore ways to make such a system a reality, is asking for $8.7 million from the state over three years to take the first steps toward completing the project. The money would be used to hire a project manager and support staff who would gather public input and prepare a plan that would define the passenger rail route and station locations and provide cost estimates.

While the route is far from finalized, state transportation officials have discussed a line stretching from Fort Collins to Pueblo, which would probably cost between $5 billion and $15 billion, according to CDOT.

The commission’s road map entails five “phases,” including final design and construction. The 15-year process would include developing a financial plan, determining who would operate the system and acquiring right-of-way. Just completing initial design plans, along with the required planning studies and reviews, is estimated to cost $150 million to $300 million, according to the document.

The discussion of passenger rail has risen to the forefront of Colorado’s transportation landscape as state, local and regional leaders struggle to maintain roads and build new infrastructure with existing budgets as the population rises along the Front Range. Proponents see rail as a more efficient, long-term transportation solution than adding lanes to overburdened highways like Interstate 25.

Though funding and other formidable challenges remain, commission member Jill Gaebler called the submission to the Legislature an “exciting” development.

“This is the first time that we see a light at the end of this tunnel for a sustainable transportation mode along the Front Range,” said Gaebler, president pro-tem of the Colorado Springs City Council.

The commission is also considering options for adding stops in Pueblo and Walsenburg to Amtrak’s Southwest Chief line. The group was initially established in 2014 to come up with a plan to repair more than 100 miles of track on Amtrak’s Chicago-to-Los Angeles line, which has stops in Lamar, La Junta and Trinidad.