Going to or coming from Hermosillo from Nogales you will encounter several checkpoints. On the north bound side there is a checkpoint manned 24 hours a day by the Mexican military. The soldiers posted at the stop sign who speak to the drivers are almost always able to speak enough English to deal with American and Canadian tourists. They will ask you where you are going, where you are coming from, and may ask to see your ID. Random and suspicious vehicles will be directed to a parking area to be searched, if you are selected to be searched the process normally takes less than 5 minutes (assuming you aren't carrying anything you shouldn't be). They will search through your bags, and the interior of your car. There may also be Federal Preventative Police (PFP) checkpoints, these checkpoints are often set up in different locations. Most PFP Police Officers will speak english, but will normally wave through any vehicles with American or Canadian plates, so long as the occupants are obvious tourists (break out your straw hats, brown shoes, and black knee socks!)
Hermosillo is about a 7 1/2 hour drive from Phoenix, Arizona, about 4 to 4 1/2 hours from Tucson, and about 3 hours from Nogales, Sonora. That is assuming you drive the speed limit. It is not unheard of to have the previous mentioned times to be much less when the border crossing is not congested. Also (and this applies for all of Mexico) The Mexican highway patrol has a modern fleet of Dodge Chargers, all of them have video cameras and many of them have K-Band radar. So bring your radar detector. Mexican regulations don't explicitly prohibit detectors nor are they sold in the country, however, that does not mean cops aren't familiar with these devices. So if you get pulled over with your detector, don't expect the cop to be so nice anymore if he notices it (just like in the US). As with any cop either side of the border, be nice to them and they'll be nice to you.
