Drive Interstate 5 to the San Ysidro border crossing. The drive can take anywhere from 45 minutes to three hours depending on traffic. Have your passport ready. If traveling with children other than your own, you need their passports and documents signed and notarized by the legal guardians stating you have permission to take them on the trip.
Purchase Mexican auto insurance for your vehicle. If you do not have insurance, there are places before the border crossing where you can purchase and get printed copies of insurance.
Stop at the custom's booth and answer the customs guard's questions. When cleared, proceed. I-5 becomes Poniente. Take Poniente to Tijuana. The drive past customs is 15 minutes.
Purchase a ticket for passge to Tijuana on the Red Trolley at the San Diego Trolley office. Board the Red Trolley and get off at the San Ysidro crossing. Fares vary depending on age and how many trips you plan to make. Average fares as of 2010 are between $5 to $10.
Walk the overpass across the highway and go to a custom's turnstile and guard. Present your passport and answer all questions.
Walk onto Avenida Revolucion and continue into downtown Tijuana.
