All southbound lanes of Interstate 5 from the split with Interstate 805 to La Jolla Village Drive will close Tuesday at 9 p.m. as part of the construction of a new Gilman Drive Bridge.
The bridge will connect Gilman Drive with Medical Center Drive over the I-5 freeway. Its construction began in 2016 and it's scheduled for completion in 2019.
Beginning overnight Tuesday, construction crews will pour concrete to establish the deck of the new bridge.
Anyone traveling on southbound I-5 will be detoured to southbound I-805 from 9 p.m. Tuesday to 5 a.m. Wednesday.
Northbound traffic will face partial closures from Nobel Drive to Voigt Drive.
Heavy equipment, including an industrial-sized pump, will be on the lanes of I-5 during the overnight work, SANDAG officials said.
There are 700,000 vehicle trips on I-5 in San Diego County every day, according to Caltrans and SANDAG.
By 2030, the number of trips for the same stretch of road is expected to reach more than 1,000,000 a day due to population growth in Southern California.
Without improvements to the North Coastal Corridor, the agencies estimate the same trip on I-5 that took 39 minutes in 2006 will take 80 minutes in 2030.