This is a connecting interstate in the Denver Metro Area. It connects I-25 to I-70; running north and east from I-25 curved outward. Its endpoints both are in Denver itself, but most of its length is in Aurora, Colorado. Getting on it from I-25 it has two lanes paved in concrete, though it expands to three and four north of Colfax Avenue.
One of the most infamous interesections in the city is this freeway's connection with Parker Road. As of AD 2000 it is being rebuilt, but any solution to the horrendous back ups on Parker Road are years away. I-25 and I-225 are often jammed at rush hour due to the heavy traffic from the nearby Denver Tech Center. Sometimes this interchange is called the "choke point" or the "timewarp" due to the old and narrow nature of the freeway bridges.