US 15 in Frederick is a subject of the I-270/US 15 Multi-Modal Corridor Study, which encompasses the corridor of the two highways from I-270's interchange with Shady Grove Road in Montgomery County to north of US 15's intersection with Biggs Ford Road north of Frederick. The study was started by the Maryland State Highway Administration (MDSHA) and Maryland Transportation Authority in the mid-1990s to examine upgrades to the highway and transit infrastructure within the corridor. As part of another long-term project initiated by the I-70 Corridor Planning Study, Jefferson National Pike's interchange with I-70, which was constructed with two ramps in 1969, received two ramps from eastbound I-70 in 1997; that same year, access from northbound US 15 and US 340 to westbound I-70 was added at the Frederick Freeway interchange. Exit numbers on US 15's portions of Jefferson National Pike and the Frederick Freeway were changed to their present numbers in 2002. The interchange between Jefferson National Pike and the Frederick Freeway was transformed from a cloverleaf to a partial cloverleaf interchange in 2004. Access between US 15 and the northern end of MD 355, then named Wormans Mill Road, was removed in 2006, the same year a ramp was added from westbound MD 26 to northbound US 15. The roundabout at the US 15–MD 464 intersection in Point of Rocks was built in 2009.