Interstate-225 rail line is a 16.9km-long light rail transport project developed by Denver’s transit authority Regional Transportation District (RTA).

The new line starts from the current terminus of the existing Nine Mile Station and connects to Peoria Station on the East Rail Line.

Running through Aurora City, the line serves Aurora City Centre, the Anschutz/Fitzsimons Medical Centre, Denver International Airport and the new VA Hospital and Children’s Hospital.

Environmental evaluation for the $350m project was completed in 2009. Kiewit Infrastructure made an unsolicited proposal in March 2012 to construct the new rail line.

The groundbreaking ceremony was held in May 2012, and the full line was opened to the public as R Line in February 2017.

I-225 rail line details

The I-225 line has eight stations, namely Iliff, Florida, Aurora City Centre, 2nd-Abilene, 13th Avenue, Colfax, Fitzsimons, and Peoria.



Gold Line is the new 11.2 mile electric commuter rail transit line being developed by Regional Transportation District (RTD).


The rail line development is part of a voter-approved transit expansion programme known as FasTracks, which includes the construction of 122 miles of commuter and light rail, 18 miles of bus rapid transit service, Denver Union Station redevelopment and bus services for connecting the eight-county district.

The first phase of the project comprised a 2.4km-long line, referred to as the minimum operable segment, between Iliff and the Nine Mile light rail transit stations.

The segment extends from the existing terminus in the I-225 median and cross over the northbound lanes on a bridge structure before continuing on the east side of the line. It also passes through the rebuilt Yale Bridge, reopened in October 2012, in order to provide room for the light rail expansion and the road extension.

The railway line consists of 1,800 new parking spaces at stations.

Communication system on the new light rail

As the hub for the new rail line, the communication system collects information from elements such as the variable message signs (VMS), CCTV and public address systems. The gathered data is sent to the operations control centre via a fibre optic cable for managing train operations.

The traction electrification system comprises 11 traction power substations, which act as the main power source for the trains. The substations transmit 825V of direct current to the trains through an overhead catenary system.

Rolling stock and ridership

I-225 rail line uses double-ended light rail transit vehicles. The first train, manufactured at the EVRAZ plant in Pueblo, arrived in February 2014 and runs in segment 1 near Harvard Avenue.

The light rail vehicles are maintained at the Elati Light Rail Maintenance Facility located at 2701 South Elati St in Englewood.

I-225 rail line is expected to accommodate an estimated daily ridership of 34,400 passengers by 2035. Trains on the line run every ten minutes during peak hours and fifteen minutes during off-peak time.

Construction of I-225 rail line

Construction works on the segment between Nine Mile to Iliff began in 2012, in collaboration with the Colorado Department of Transportation (CDoT).

“The I-225 Rail Line is estimated to witness a daily ridership of 34,400 passengers by 2035.”

Work included the construction of three lanes in each direction along with an additional auxiliary lane, as well as the widening of the I-225 highway between Mississippi Avenue and Parker Road, which began in May 2012. CDoT and RTD funded the works, which were completed in 2014.

Other major works include the construction of bridges at Iliff, Mississippi, Sixth Avenue and Colfax Avenue.

Contractors involved

SEMA Construction was awarded the contract for constructing the line segment from Nine Mile to Iliff. The contract includes the rail guideway design and bridgework for the widening of the I-225 from Mississippi Avenue to Parker Road.

Construction of the I-225 line from Iliff to Peoria / Smith Station was undertaken by a team of Kiewit Infrastructure, Mass Electric Company, and RBC Capital Markets.

AECOM was engaged to provide the design for the I-225 project.