Effective yesterday, there's a new freeway in Metropolitan Phoenix: the South Mountain Freeway, which completes a larger project called the Loop 202, the innermost of several more-or-less concentric rings that encircle this sprawling megalopolis in the desert. It was the largest single freeway project in the history of the state. Just 22 miles of new road, but it cost $1.7 Billion dollars and three years to build it, and now that it's done, all of us locals get to breathe a long sigh of relief. There are 4.5 million people living in Metro Phoenix, and thanks to our mild winters and interminable sunshine, we get five times that many, some 22 million people who visit here each year. That's a lot of people, so the traffic in this town is completely %#$@! (pardon my French).
If all you're doing is passing through on Interstate 10, traveling in either direction, you'd be doing yourself a favor if you take steps to avoid the worst of that traffic. Our standard advice here on RTA is to bypass metro Phoenix altogether, using Interstate 8 and AZ 85. This route, highlighted in blue on the map, takes you through Gila Bend, and traverses about 100 miles of some fairly bleak desert.
The new route, highlighted in red, does NOT bypass the metropolitan area, but it DOES bypass downtown Phoenix and the worst of the traffic by taking you around the back side of the mountains that form the southern backdrop to the city skyline. It's at least 15 miles shorter than the route through Gila Bend, and as long as you avoid the peak commute times, it will save you time, as well as distance.