The SR 76 Middle Segment is the second of three improvement projects to the SR 76 corridor between I-5 and I-15 funded by the half-cent sales tax known as TransNet. The first, SR 76 West, was completed in 1999 and improved the highway from I-5 to Melrose Drive. The third will be SR 76 East, which will continue improvements from South Mission Road to I-15.

The Middle Segment from Melrose Drive in the City of Oceanside to South Mission Road in Bonsall measures 5.5 miles and serves a mixture of local, regional, and interregional traffic. This segment carries an Average Daily Trip volume of 33,000-42,000 vehicles per day. Roughly half of the trips along this segment originate within the communities of Fallbrook and Bonsall, and the cities of Oceanside and Vista. The remaining trips within this segment of the corridor are a mix of interregional trips originating in Southern Riverside County and commuter trips between I-5 and I-15. Most intersections operate above capacity, and traffic queuing is common during peak travel periods.