Can I take the trolley to the Mexican border?
Yes. The Blue Line's southern terminus is San Ysidro Transit Center, immediately north of the port of entry, and it costs $3.00 one way. Walking across is the easy part — coming back is where the queue is.
- Line
- Blue Line to San Ysidro
- Fare
- $3.00 one way
- Age 18 and under
- Free
- To come back
- Passport or passport card
Southern terminus is the border
$1.50 Senior/Disabled/Medicare
Youth Opportunity Pass, through June 2027
A driver's licence is not enough
The short version
- The Blue Line runs from downtown San Diego to San Ysidro Transit Center, its southern terminus, just north of the San Ysidro Port of Entry.
- One-way adult fare is $3.00, or $1.50 at the Senior/Disabled/Medicare rate, from the October 1, 2026 region-wide increase.
- Riders 18 and under travel free on MTS through June 2027 under the Youth Opportunity Pass.
- Taking the trolley means you don't queue in a car and don't pay to park all day.
- The northbound pedestrian queue back into the US is the unpredictable part — check CBP's live wait times before you commit to a return time.
San Diego is the rare American city where you can reach an international border on light rail. The Blue Line ends at San Ysidro Transit Center, which sits immediately north of the San Ysidro Port of Entry — the busiest land border crossing in the western hemisphere — and connects by pedestrian walkway to the outlet shopping on the US side.
Two ways to reach the border
The trolley's advantage is not really speed — it is that you are not sitting in a vehicle queue at the border, and you are not paying to leave a car parked all day.
What it costs
$3.00
One way, adult
From October 1, 2026
$1.50
Senior / Disabled / Medicare
SDM reduced fare
Free
Age 18 and under
Youth Opportunity Pass
So a return trip to the border is $6.00 at the adult fare. Whether a day pass beats that depends on the day-pass price — and this is a case where we would rather point you at the source than print a number we can't stand behind: MTS's fare-change materials set out the new one-way and monthly fares but do not publish a day-pass figure alongside them. If you expect to ride three or more times in the day, check the current MTS fare chart before you tap, because the daily cap is what decides it.
Going is easy. Coming back is the trip.
- Bring your passport or passport card. A US driver's licence is not enough to re-enter, and this is the mistake that ends day trips at the border.
- There are two pedestrian crossings at San Ysidro, and their hours and queue lengths differ. Check which is open before you plan a late return.
- The trolley runs late, so a long northbound queue does not strand you — but confirm the last departure rather than assuming.
KEEP READING
SOURCES
Everything above traces back to one of these. Follow them — if one has changed and we haven't, that's our mistake, not yours.
- PrimaryFares & Passes
San Diego Metropolitan Transit System · Checked September 8, 2026
The $2.50 adult one-way, $1.25 reduced fare, $6.00 day pass, and the Youth Opportunity Pass for riders 18 and under.
- BackgroundSan Ysidro Transit Center
Wikipedia · Checked September 8, 2026
That the station is the Blue Line's southern terminus, sits just north of the San Ysidro Port of Entry, and connects to the outlet centre by pedestrian walkway.
San Diego MTS · Checked September 8, 2026
Current Blue Line timetable, including first and last departures.