On Sun, 27 Jun 2004 19:38:58 +0100, Grant Mason wrote
(in message ):

There is a difference here. The study you quote is specifically about
traffic calming - a mix of reducing speed limits, reducing road
widths, signage, road markings etc. I would expect, in general, that
if you lower the speed limit AND give the appearance that it may be
enforced then speeds are likely to drop.

Indeed.

But a number of the villages (including the one I live in) in the study had
no reduction in speed limit - only changes to signage. And average speeds
did drop, contrary to the original assertion.

I don't think anyone asserted that traffic calming won't reduce speeds - the
discussion was over something totally different. Basically, if there were no
bend hazzard warning signs at all, would drivers tend to drive slower in
general on the basis that they have to concentrate on the road and be
prepared for bends, rather than stick their foot down, rely on signs to
announce bends, and complain if they get caught out on an unsigned bend ?

It's notable that only 3 (ie one third) of the test sites did NOT have a
speed limit reduction. All had some form of speed camera, and the signage to
go with it. I would suggest that lowering a speed limit and putting a speed
camera somewhere is likely to reduce speeds - but not neccessarily increase
safety overall.

One of the key things here is that many of the markings are not there as
'signs' in the 'here is a piece of information for you to read' sense. It
seems that the main message from the report is that the most effective
measures were those that either physically or visually made the road smaller
(dragons teeth, painted out areas, hatched areas, chicanes, and refuges),
together with surface features that break the smooth black strip (especially
the rumble strips).

IMHO, this confirms the theory that the best way to reduce speed is to make
the driver feel that a lower speed is appropriate - eg (in simplistic terms)
if a road is wide and straight then it's fast, but if it's narrow and windy
it is much slower. Removing ALL road markings is a variation on this - remove
road markings and it's not clear how much road is 'yours', whether there are
any tight bends, etc.

What concerns me though, is this ...

If EVERY place has all the features used in this study, do you not think that
drivers will simply become immune to them and speeds go up again ? And what
does it do to nearby places that DON'T have these measures - relatively
speaking, they are now 'visually safer' roads and speeds might actually
increase there. Sticking ONLY to speed limit signs, do you not think that
with the ever increasing number of them, drivers are simply taking less
notice of each of them individually ?

As an analogy, if you hear a siren from an emergency vehicle, it grabs your
attention. If you heard it very frequently (like every few minutes) then
you'd more or less ignore it. Modern signage is like that, it's no longer
informative to see a sign because they are too commonplace !

Simon