The possibility of a passenger rail line between Phoenix and Tucson has moved a step forward, and the Arizona Department of Transportation is now asking the public for feedback.

There are two main rail routes to choose from, ADOT spokesperson Laura Douglas said

The yellow and orange alternative would both share a corridor with the Interstate 10 and connect Phoenix and Tucson through the East Valley and Pima County. The yellow alternative is expected to cost $4 billion to $5 billion. The orange alternative is slightly more expensive, at $6 billion to $8 billion, Douglas said. The rail system would offer a blended service of daily commuter, local and express trips.

“It’s a potential alternative to traffic along I-10 and it really provides a way for people to get from Phoenix to Tucson quickly,” Douglas said.

According to ADOT, yellow alternative service could top 5 million passengers annually by 2035. The project is currently unfunded, and ADOT will be taking public comments this week at locations in Phoenix, Tucson and Coolidge to determine the future of the rail system.

Read more about the study here.

Sept. 15: 5:30 to 7 p.m. — Phoenix Public Library, Burton Barr (1st Floor Pulliam Auditorium) 1221 N. Central Ave., Phoenix, 85004

Sept. 16: 5:30 to 7 p.m. — Tucson Convention Center (Leo Rich Theater) 260 S. Church Ave., Tucson, 85701