A series of freeway closures will take place on Interstate 5 (I-5) and on the Balboa Avenue off-ramp in the coming weekends in order to accommodate construction activities for the Mid-Coast Trolley Extension Project.
The northbound I-5 off-ramp at Balboa Avenue will be temporarily closed during the following dates: 
·  Friday, May 19 at 7 p.m. through Monday at 5 a.m.; and
· Friday, June 2 at 7 p.m. through Monday, June 5 at 5 a.m.
Crews will install infrastructure to support a new railroad bridge on Balboa Avenue/Garnet Avenue. Changeable Message Signs will placed in advance of the closure detouring motorists to take the northbound I-5 exit at Clairemont Drive/Mission Bay Drive.
Additionally, between 6 and 8:30 a.m. Sunday and Sunday, June 4, motorists will encounter a series of intermittent traffic closures up to 10 minutes on northbound and southbound I-5 near Balboa Avenue. The rolling closures are needed to relocate electric distribution lines across the freeway. Closure duration may be longer if necessary to ensure public safety. 
No closures will take place during the Memorial Day weekend.
The Mid-Coast Trolley Project will extend Blue Line service from Old Town north to the University City community The San Diego Association of Governments (SANDAG) began major construction on the project in 2016, with service anticipated to begin in 2021.