[kzrdude]

The map projection on google maps is only chosen to produce good maps at every point by themselves (square city blocks will still be square, wherever you zoom in). I assume they would have chosen a different design (a globe) if they designed it to be used as a world map service.

[jofer]

No, it's chosen because it preserves direction. They use a single Mercator projection centered at the equator.

It's a pragmatic choice, but it's certainly not chosen to produce good local maps. It produces bad local maps everywhere except the equator.

If they wanted to produce "good maps at every point by themselves", they'd use a different projection every time you recenter the map.

It's a terrible projection at every point not on the equator. However, it does preserve direction, so straight N-S or E-W streets will appear perfectly straight.

However, square city blocks _do not_ appear square. You just don't notice the distortion unless you're quite far north or south.