Nowadays I do care about such things, and have found myself fumbling around in the Labyrinth Lord rule book, trying to work out how many miles per day a party can travel through various types of terrain. It's not that complicated, I know, but somehow it's non-trivial enough that I have to spend time each session recalculating it. So I thought I'd try to come up with an easier system. All I've done is pre-calculated all the fractions and formatted it all into a table (see above) so that only a single look-up is required. Simply cross-reference the party's movement rate (i.e. the movement rate of the slowest character in the group) with the terrain they're travelling through, and you get the number of miles they can move in one day. The percentage chance of getting lost is also listed, for convenience.
I hope someone else finds it helpful too!