I wasn't sure about the accuracy of Google-related measurements, so I found the nearest running track on the map, and measured a lap of that on the inside lane. 400m spot on.
Accurate enough for me.
There does seem to be something of a grey area with regard to how, or if, Google takes into account the amount of climbing and descending that may be involved in a measurement. To all intents and purposes, the Google measurements appear to be done on a
flat surface; as it appears on the computer screen. If the elevation isn't considered, then I think that a hilly run will actually be
longer than the distance registered. I'm not certain if anyone has come up with a definitive answer to that question (though I may be wrong... But if they have, I've not come across it).
I suppose it's possible to compare two measurements as they appear on the screen, with one being a straight line on a known
flat road; the other being a straight line on an incline. Measure a mile (or whatever) on each surface and compare the actual lengths of the lines as they are represented on the screen. If elevation is taken into account, then the inclined measurement should be
shorter on the screen.
Maybe I'm wrong. It's a bit early for this kind of stuff, anyway!
