San Ysidro

      Imagine a large metropolitan area, say five million people, physically split in two by a river or a mountain or any other physical barrier, the two sides connected by a single crossing.  Now take into account that this crossing doesn't just link the two sides of the metropolitan area but is also a critical segment of a vast transportation network that links people and places far beyond the limits of the local region. 

      Finally, consider that this physical barrier separates not just two sides of a region but two nations, one vastly wealthy and one tremendously poor, and you have the perfect recipe for a memorably chaotic bottleneck.

      While large flows stream into Tijuana unfettered, an endless queue of cars and pedestrians await their turn to convince American border patrolmen to let them in.  Some are San Diegans and other American tourists who made a day trip to TJ to buy cheap drugs and get drunk.  Some have traveled all the way from Chiapas and points south to risk their lives jumping the fence.  But many, if not most, are Tijuanitos who commute through the border madness everyday to jobs in San Diego.  For them it's about as exotic as a Starbucks drive-thru.