This blog explores the history of Phoenix, Arizona and a little bit of Los Angeles and San Francisco, California

Why the railroad tracks switch from your left to your right going north on Grand Avenue


If you're a neighbor of mine, in the northwest valley, chances are that you have driven north on Grand Avenue and gone under something called the "Peoria Underpass". It's south of Olive, and it's where the railroad tracks cross over Grand Avenue. Or, if you prefer, it's where Grand Avenue passes under the railroad tracks.

If you never noticed it, that's not surprising. For me, the thing that I always noticed was that the railroad tracks switched from being on my left to being on my right as I went towards Sun City on Grand Avenue. And to understand why, you have to time-travel a bit. Come along with me.

Contrary to popular belief, Grand Avenue was built before the railroad tracks. Yes, that's unusual, as usually towns grow up along railroads. But Grand Avenue was different. It was privately funded by the men who built the Arizona Canal, in 1885, and it was the route from Phoenix to the new towns of Glendale (where I live), and Peoria. Take a look at a map, starting at the city limits of Phoenix in 1885, which was Van Buren and 7th Avenue, and draw a straight line to Glendale. That's Grand Avenue. If you keep going straight, you'll go through old town Peoria. If you keep going, of course, you'll cross New River and the Agua Fria River, going through Sun City and then all of the way to Wickenburg.

But the original Grand Avenue was only built to the town of Peoria. Of course, you could continue on to Wickenburg, on foot, on a horse, or on a wagon. And this is the part that you engineers will really like - that roads can cross rivers at a sharp angle, but railroads can't. So the original Grand Avenue crossed the rivers at too oblique of an angle for the railroad, which must be 90 degrees, and so when the railroad tracks were laid down, they didn't quite align with Grand Avenue, especially north of Glendale.

It was really just a small difference, but since the tracks needed to cross the rivers at that 90 degree angle, the tracks crossed over Grand and aligned just slightly west. That's why the railroad tracks don't go right through the middle of old town Peoria, they're over to the east.

Of course, Grand Avenue was realigned to go along the railroad tracks. And in order to keep traffic moving, the city of Peoria built an underpass at the crossing.


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