The Curious Case of a Gonzo GPS?!

Feb 09, 2009

RAY: This is from my Open Road series and it was sent in by John Robinson.

He writes:

'I have always been a gadget nut. And when the first portable GPS units hit the market in early 2000, I just had to have one. Since then I have upgraded 5 or 6 times.

We travel a lot in our RV and it's perfect for exploring new and exciting lands. I have never experienced any technical problems with any of the units until now.

After returning from a trip and resting for a week we headed out on a new adventure. When I went to reset the trip information on the GPS, I discovered what I believed to be a major problem. The GPS was telling me I had driven some 28 hours on the last trip, my maximum speed was 72 mph, but my average speed was 159 mph.

I don't know a whole lot about math, but I do know you can't have an average speed that's greater than the maximum speed. So I reset the unit. I even contacted the manufacturer, ran lots of diagnostics and the unit seemed to perform perfectly.

As a last resort I used that time-honored method of throwing it down the stairs. When I went to pick up the pieces, I figured out what had happened and there was nothing wrong with the unit or its calculations. What could possibly account for this strange behavior of my GPS?'
RAY: Here's the answer:

My wife and I recently celebrated our tenth anniversary, and before we left on our trip, we programmed all of the sites and restaurants and other senior points of interest into the GPS so we could maximize our enjoyment.

TOM: Yeah.

RAY: During our two weeks that we were gone the GPS logged a driving time of 28 hours, and a maximum speed at 72 miles an hour, so far so good, right?

TOM: Yeah.

RAY: Now here's what happened next. We then jumped on a plane. And flew home from Hawaii to Alabama, which is 4,000 miles. Of course, on the flight the GPS was in my suitcase and turned off, but when it was turned back on it realized it had traveled some 4,000 miles. Thus the computations were correct, a total of 4,452 miles for an average speed of 159 miles an hour. Pretty cute, eh? Who's our winner?

TOM: Excellent! The winner this week is Dean Wilson from Navasota, Texas, and for having his answer selected at random from among all the correct answers that we got, Dean's going to get a $26 gift certificate to the Shameless Commerce Division at with which Dean can get a copy of our latest CD collection called Field Guide to the North American Wacko.

RAY: Congratulations, Dean!

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