What's Driving You Crazy?: The two separate Colorado Boulevard exits on I-70 "I thought exit names must be unique in any one state" Why are there two separate Colorado Boulevard exits on I-70? and last updated 2021-05-05 06:07:22-04 Mark from Golden writes, âWhatâs Driving You Crazy? Hi, Jayson. Why are there two Colorado Boulevard exits in the state of Colorado? Thereâs one in Denver, obviously, but thereâs also one in Idaho Springs on westbound I-70. I thought exit names were to be unique in any one state.â This is one of the most interesting questions I have received over the years. There is no official requirement in Colorado, or the United States, where exit names have to be unique to one location, although most are.