The Colorado Department of Transportation has received the green light from the federal government to move forward with $2.18 billion in improvements to Interstate 25 and other major roads, a commuter rail service and bus system and other transportation upgrades in Northern Colorado.

The department announced in a statement Tuesday that it will seek federal funding and go forward with additional planning for the improvements, which include a new lane in each direction of the interstate between state highways 66 and 14. The announcement follows an environmental impact analysis by the department that received approval from the Federal Highway Administration on Jan. 3.

"Now we're able to move forward and start identifying funding sources to move the transportation elements into construction," transportation department spokeswoman Mindy Crane said.

As part of the improvements, the department plans a commuter rail service with nine stations connecting Fort Collins and Longmont using BNSF Railway Co. right of way.

Along with the commuter rail, the state would build an express bus system with 13 stations along the interstate, Harmony Road and U.S. 34. Buses would run from Fort Collins and Greeley to