From Wired Magazine co-founder Kevin Kelly's web site
Throughout Mexico "topes" or speed bumps, are ubiquitous. These can be metal pods arrayed across the road, or asphalt humps, or even significant concrete wedges. You really do have to slow down, andalmost stop to crawl over them. There is usually a sign warning theyare ahead, because if you hit one going fast you can total your car. Inother words, the topes are effective. Small towns will have one comingand going, because they are more effective than speed limit signs,which everyone would ignore. But even highways have them, nearintersections or bus stops.
Along the southern coast of the Yucatan, beyond the last electricityand asphalt, at the end of the road, the Mexicans still want thebenefit of a tope, but what to do on an unpaved mud/sand road? Wellalong the coast, where old ship ropes can be found, the solution is tolay a big fat rope across the road. It works, at least for a while, butit is easily replaced. This one is strung across the road in the small pirate town of Xcalak, Yucatan.