A categoria em Dirigir no México em Wikitravel tem algumas coisas a dizer:
Never drive above the speed limit or run stop signs/red lights as Mexican police will use any excuse to pull over tourists and give you a ticket. If pulled over by a police officer soliciting a bribe, do not pay the amount requested, but pull out USD$50 or 500 pesos, and explain that it is all you have. This technique has worked in the past (but it does not work in Mexico City), but it is corruption. Corruption also is a crime in Mexico, so make a conscious choice. The fine for speeding could be as much as US$100, depending on the city.
As of April 2011, Police across the country are cracking down on drunken driving, particularly in Mexico City, the larger cities and the beach resorts. There are random checkpoints throughout the country in which every driver has to stop and take an automated inebriation test. If you fail, you will end up in a Mexican prison. If you wouldn't drive drunk back home, don't do it in Mexico.
Então, neste caso, isso implicaria que eles estão procurando por três coisas:
- motoristas bêbados
- acelerando os drivers
- drogas
- a oportunidade de obter um suborno (também pode ser associado aos três itens anteriores)
Isso é para a verdadeira polícia mexicana parar.
Agora, quanto a paradas policiais falsas, o Consulado dos EUA tem isto para dizer, a partir de 2010:
U.S. officials have clarified an earlier travel advisory that warned Americans against traveling after dark to Puerto Penasco, Mexico, also known as Rocky Point.
The U.S. Consulate in Nogales, Mexico, had issued the warning because travelers have been stopped by phony Mexican police roadblocks.
In an e-mail obtained by the Arizona Daily Star, the consulate stands behind its advisory, but clarifies that the warning only advises against traveling on the highway to Puerto Penasco at night and didn't apply to other highways in the Mexican state of Sonora or in the city of Rocky Point itself.
Alguns outros resultados parecem indicar algum preconceito contra pessoas do estado do Arizona especificamente, como visto em este tópico :
...there's people down in Mexico looking for people from Arizona. Fake police and fake roadblocks. I doubt anything good will happen to someone who is found out to be from Arizona.
There was a tourism ad released not too long ago that Sheriff Arpaio sees as threatening to AZ citizens, and this may be related to that.