The San Ysidro Port of Entry is the largest land border crossing between San Diego and Tijuana, and the fourth-busiest land border crossing in the world with 70,000 northbound vehicles and 20,000 northbound pedestrians crossing each day, in addition to southbound traffic. It connects Mexican Federal Highway 1 on the Mexican side with Interstate 5 on the American side. The San Ysidro Port of Entry is one of three ports of entry in the San Diego–Tijuana metropolitan region.