It's bound to happen during any road trip south of the border. You'll need to go really badly, and the roofless, doorless, toilet-paper-less cinder block shell marked "Baños -- 5 Pesos" will offend your dainty sensibilities.

It'll be tempting to take a quick leak on the side of the road, trucker-style, but as I learned, if you do, just be sure to check for a truckload of Federales before you unload and unzip.

For me, the moment came a little over a week into our 2010 Mexican expedition. We'd just wrapped up a week at a marginal timeshare in an "up-and-coming" resort area on the Sea of Cortes that seems to be much more down-and-out these days. It felt a little bit like spending a week with Cabo's little brother, the one who'll kick your butt at pool, but can't quite get his act together in any of life's more important areas, like warm showers.

But the thing is, even in a cut-rate Mexican resort, the baños are like heaven compared to what's offered at a rest stop along any of the carreteras. Standard roadside facilities may appear civilized and refined from a distance, but once you've locked yourself in with the commode, you'll likely realize the seat is missing -- the toilet paper, paper towels and soap are technically not missing, because they're considered an extra bonus when provided, kinda like whipped cream on your sanitary latte -- and my personal favorite is when they're "flushed" by pouring a gallon of water from a provided barrel into the bowl.

Did I mention that before you can enter this lavatorial gauntlet you'll be asked to pay a few pesos for the privilege? (Ok, it's only roughly equal to a quarter, but we're talking about the principle here.)

It was these thoughts of the relatively luxurious bathroom experiences I'd had in the previous week and the injustice of the common Mexican restroom that flashed through my mind when we stopped briefly to switch drivers on the side of a carretera. I had been holding it for nearly an hour, and there was a line to use the few standard-issue baños next to a gas station a mere 50 yards away.

Glancing at the ditch that separated me from relief, strewn with litter and a few bushes for cover, it seemed easy to justify the decision -- whip it out, get it done right here, get back in the car -- no lines, no nastiness.

And I almost made it.

Just as I was ready to zip up, I heard the wheels of the Federal Police truck screech to a melodramatic halt on the gravel behind me and give the cursory half-second blip of its siren that translates to "busted!" in any language.

I took the time to zip up, but left my belt undone to let the Federales know I wasn't intimidated, which I actually was, but with my bladder empty, I felt confident that they'd never know.

"Que Paso?" said the officer hanging out the passenger side window.

"Una emergencia," I responded like a 2nd grader caught while, well, pissing on the playground.

While my spanish isn't so hot, I'm pretty sure his response was 'Hey stupid gringo, you're standing 66.3 meters from a bathroom, but instead you choose to piss all over my country in front of me and everyone else?"

"I don't know. No se," I replied. "Yo el estupido. Lo siento. Sorry, sorry." I backed away with each word, turning around at the end to buckle my belt. Hearing no protest, I just kept walking rather than wait for permission to go. I stole a quick glance back as I reached out for the handle of the car door. Clearly there was no code in the Mexican, uh, penal system for insulting and impractical urination.

We started moving and the police truck turned the other direction. I felt rattled, embarrassed ... but my protest had succeeded -- I had pissed in the face of Mexico's unjust system of rusty old public baños, my bladder was relieved, and best of all, it hadn't cost me a dime.

Eric Mack is an Asylum Contributing Editor. He barely made it back over the border.