Starting at Via Lido on Newport Boulevard in Newport Beach, south of SR 1, SR 55 (Newport Boulevard) is a four-lane expressway for approximately to its intersection with 17th Street in Costa Mesa. It then follows a traditional street routing through a retail and commercial section of Costa Mesa until its intersection with 19th Street. The segment on Newport Boulevard includes a limited-access interchange at SR 1. Following the 19th Street intersection, SR 55 becomes an eight-lane below-grade freeway that bisects the northbound and southbound lanes of Newport Boulevard until the Mesa Drive undercrossing.