In news:fn8d0l$rhn$1,
Robin Stevens <rejs> tweaked the Babbage-Engine to tell us:

> Wearing was made compulsory within my lifetime - I am guessing early
> eighties, given I clearly remember it.

1982[1] for front seat belts; 1991 for rears.

A bit of searching suggests 1965 as the year in which fitting front seat
belts into motorcars became compulsory.

1 - or 1983, depending on whether one believes the Department of Transport,
or the Bedfordshire and Luton[2] Casualty Reduction Partnership

2 - last time I looked, Luton was in Bedfordshire. Has the Luton Popular
Front succeeded in gaining independence or something?

In article <fn7hoh$cef$1>,
nmm1 (Nick Maclaren) wrote:

> In article
> <droleary.usenet-D8608C.07571723012008>,
> Doc O'Leary <droleary.usenet> 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.

Then your motives are biased and you're better off simply faking the
"science" to show the results you want.

> 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 ....

Don't pretend like you're looking for actual evidence either. Also
realize you're posting to an international forum where many/most people
have no idea what "DfT" refers to or why we should care about their use
of a 2.5 multiplier instead of 4 for some unknown purpose.

> 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!

Observation bias seems to be your best friend. Do a real study if you
want to be taken seriously and, even then, I have outlined the
difficulty in isolating the factors that contribute to a significant
difference.

James Annan wrote:
> 7.5mph [12 km/h] is barely fast enough to balance on a bicycle

If that's true, how on earth do you get started?

(I find no difficulty in balancing down to about 1 km/h.
According to my speedometer, that is -- obviously measurement
gets less accurate the slower I go. Below that I need rather
larger steering motions but can still stay upright.)

Looking for multipliers is an error-prone game. How fast do
pedestrian's walk? Which pedestrians, commuters? I'd expect you can
find some published papers with estimates. Not so hard to do with time
the right software and time lapse photography. Sampling the people in
one location is not much of a problem. Just photograph them in numbers
from overhead. Sampling time of day and locations is a greater
challenge. But, protocols and measurement challenges are all in the
traffic engineering literature.

Harry Travis
USA

Dave Larrington wrote:
> 2 - last time I looked, Luton was in Bedfordshire. Has the Luton Popular
> Front succeeded in gaining independence or something?

It us a Unitary Authority.

On 23 Jan, 14:08, n...@cus.cam.ac.uk (Nick Maclaren) wrote:
>
> 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.

For the same expenditure of energy, cycling certainly is four times
faster, of that there is great deal of sound scientific evidence. But
when cycling, a person does not necessarily choose to expend the same
amount of energy. It is entirely reasonable to take advantage of the
greater efficiency provided by the bicycle, to get to one's
destination with less effort as well as somewhat more rapidly.

Only those who enjoy cycling for its own sake, or feel they have
something to prove, have the motivation to work as hard as they
reasonbly can on a bicycle. For the average man or woman in the street
it is very much an energy saving device. So whilst the contributors of
this forum may well ride four times as fast and as far as any
pedestrian, it is perhaps not unreasonable to expect something less
from the average commuter.

Cambridge and Holland are similar in providing an environment in which
people are happy to just hop on a bike, simply for convenience,
instead of walking. Elsewhere in Britain, cycling is so unusual that
people would generally rather walk. So a lot of the cycling journeys
in Cambridge and Holland are very short, without much incentive to go
particularly fast since they'll only take a few minutes and be
somewhat quicker than walking anyway.

On the other hand, a lot of the commuting done by keen cyclists is
over long distances, instead of using a car or public transport, so
there is a strong incentive to go as fast as reasonably possible. It
is not reasonable to expect that more than a few other people would do
likewise, even if there were to be a general increase cycling in this
country.