In article <droleary.usenet-D8608C.07571723012008@sn-ip.vsrv-sjc.supernews.net>,
Doc O'Leary <
[email protected]> writes:
|>
|> > On this topic, I am not looking for personal speeds, but average
|> > commuting ones. Specifically, has there been a general decrease
|> > and, if so, when and by how much.
|>
|> With so many variables in play that affect average speeds, you're going
|> to have to be really specific on what you're measuring as a contributing
|> factor. I can think of any number of mechanisms that could lead to
|> significant differences, but good luck isolating them in commuters *now*
|> let alone having to dig in historical data to find a net positive or
|> negative.
No, that's not so. It depends on what I want to use that data for.
At least one of the uses needs merely the 'average' commuting speeds,
and does not need the reasons.
Specifically, the traditional rule is that cycling was 4 times as
fast as walking, meaning that realistic distances were about 4 times
larger. More recently, the DfT has started to use a ratio of 2.5
(i.e. 5 km versus 2 km). Some people have claimed that is merely
an indication of the idiocy of the DfT, but without providing a
scrap of evidence to justify their claim. Of course, the DfT hasn't
either ....
But my observations around Cambridge indicate that the DfT rule is
actually rather closer to modern reality than the old 4x rule, and
my guesstimate is that the median commuting speed is probably only
3x the median commuting speed of walkers. Give or take a hell of an
unestimated error!
Regards,
Nick Maclaren.