[5] With an end-to-end travel time of one hour and twenty-three minutes, it operates between UTC Transit Center and San Ysidro Transit Center, the latter of which is at the Mexico–United States border directly adjacent to the San Ysidro Port of Entry, facilitating easy connections across the border.

[5] Among them, the Blue Line has the highest ridership, transporting 24,389,986 total riders, or 75,160 per day, in fiscal year 2024.

[9] An extension to its namesake campus of the University of California, San Diego, as well as nine other stations, opened to revenue service on November 21, 2021.

Rush hour Blue Line trains operated from San Ysidro to America Plaza with some serving the Bayside.

[14][15] Blue Line service to Old Town was reinstated once the Mid-Coast trolley extension to UC San Diego was completed.

[21] Renovation of rail track and the final eleven Blue Line stations was completed in late 2015.

[26] An aim of the extension is to decrease demand for parking on the UCSD campus while providing direct trolley access to Westfield UTC, a popular shopping mall.

The existing SuperLoop BRT Shuttle (Routes 201/202) provides transit in and around the UTC area from the nearby trolley stations.