I-215 was built on the State Route 146 alignment between a point just east of Exit 6 (Saint Rose Parkway/Pecos Road) and Mile 0 (the Interstate 515/U.S. Route 93/U.S. Route 95 interchange at Lake Mead Parkway, formerly known as "Lake Mead Drive"). Since the Nevada Department of Transportation (NDOT) does not co-sign state routes along Interstate highways, SR 146 was truncated to its current eastern terminus at I-215. SR 146 was co-signed with I-215 from Pecos Road to I-515/US 93/US 95, even though the state highway designation no longer existed in this section when the freeway was completed. SR 146 signs were removed on I-215.