🚀 go-pugleaf

K. P. Williams (ssukwill@csug.cs.reading.ac.uk) wrote:

[ reformatted for 80 columns ]

: Anyway, why should the speed be any different at 3 in the morning.

Because the density of traffic on a road has a profound effect on the
way traffic flows, and thus on what a sensible speed is.

Take the motorways.  They were designed for higher speeds than 70mph,
but for a much lower traffic density than we have today.  At night the
traffic density is closer to (probably lower than) the design density.
It seems reasonable to expect that this will be reflected by the
maximum safe speed being higher at night than it is in the day.  For
example, during the rush hour 70mph is too fast on the M25, but at
night it is fine.

: Just because it's 3 in the morning, does not mean that hitting someone
: at 45mph will be any less dangerous does it?

No, but should be easier to avoid incidents when there is less traffic
around.  At night there are far fewer other road users to deal with,
so each can get a bigger share of your attention.  Thus you should be
able to do a better job of reading the road and predicting the actions
of other road users than you can in the day.  Obviously vision is the
main drawback; when relying on headlights, visual distance is usually
the primary constraint on your speed, and you may have to adjust your
speed when switching from main beam to dipped and back.

[ Aside: The above is referring mainly to the open road.  The fact
that you say "45mph" suggests that you are thinking mostly about urban
roads.  I agree that most urban roads present a different set of
hazards and have quite high enough limits already.  I tend to default
to discussing rural A-roads and motorways as that is where I do the
vast majority of my driving. ]

--Steve
-- 
				Steve Hunt	steve@acorn.co.uk