The freeway is a 11.959-mile-long (19.246 km) connector spur route of I-25 that acts as an eastern bypass in the Denver metropolitan area and serves Aurora.

I-225 is one of the three freeways that serves Aurora and is the only existing Interstate in Colorado that never runs concurrent with another highway in its entire length.

[10] All of I-225 is part of the National Highway System (NHS), a network of roads important to the country's economy, defense, and mobility.

The first segment of freeway that ran from sixth Avenue to I-70 received a temporary carrier route that was cosigning I-225 as State Highway 33.

[2] Immediately after the completion of the freeway, improvements at the SH 30 (6th Avenue) interchange were underway involving the overpass.

Reconstruction of the freeway between 30th Avenue and Smith Road took place between October 1992 to August 1994, which involved bridge replacements over Toll Gate Creek and Smith Road that were completed by August 1990 in an effort for the reconstruction project.

Its tracks run parallel to the freeway and also use its median and is interlined with a portion of the RTD H Line.

[18] The light rail project was approved in 2004 as part of the FasTracks program, began construction in 2012, and was completed in February 2017.