Resident makes a Mockery of Highways Agency Statistics
Submitted by: Brian on Jun 17, 2006
A letter was passed to me (see the full article for the content)
which seems to suggest that the Highways Agency statistics
for justifying the Motorway Widening project, is little more
than fiction.
The gentleman concerned, who apparently holds a BSc in Civil
Engineering, would prefer to remain anonymous. Therefore,
I have agreed (exceptionally) on this occasion to submit the
content of his letter to the Highways Agency (dated 20th March),
on his behalf. As far as I am aware, he has not yet received
any reply from them (surprise ;).
Whilst I understand the logic of what is stated here, I haven't
checked the maths in detail, and have therefore assumed the
information to be correct (after all, he's far better qualified
than me :).
--------------------------------------------------------------------------------
M1 Widening J21-30 Team
Dear Sir,
In your leaflet to justify the need for widening, you quote
that the current 3-lane motorway is carrying up to 150,000
vehicles a day. But a simple mathematical calculation, with
no measurements, suggests this cannot be true.
A car 5 meters long travelling at 70mph covers its length
in 0. 1 Seconds. If the following car is 1.5 seconds behind
(a acceptable safety distance) then a single carriageway can
support 1 car every 1.65 seconds, which is 2182 cars/hour.
Therefore, to pass 150,000 cars per day on 6 lanes would require
all lanes to be full of cars (no lorries) travelling at 70mph
nose to tail for 11 hours during the day.
I live near the motorway and while it is busy, it never matches
that level of activity. In fact, during the busiest time,
the traffic barely moves at 40mph and capacity is well down.
And these figures do not take into account the statistics
of "queuing" theory which would reduce the capacity
to only 60% of the above maximum due to the random flow rates,
which would begin to cause the infamous rubber-band effect
above that level and hence reduce the capacity.
I will be most interested to find out how you make this assertion
and what the planned capacity is to be.
Yours Sincerely,
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