Algorithm/considerations taken into account on average speed camera

Dear Sir or Madam,

Please could you supply me, in electronic format, details on how
the new 'average speed cameras' calculate this average. And also
what sort of average it is, and how successive cameras recalculate
this.

Details on other workings related to the calculation of this
average that I haven't mentioned will be considered to be included
in part of this request, be they overtly technical or not.

Yours faithfully,

Simone Barrett-White

Dear Mr Narroway,

I have followed the link you sent, but this states that I need
Windows XP to view. I have not got, at home nor in work, access to
any Windows computers. Could this be made available in a
non-proprietary format so I may view it?

Also, I don't deem it a valid response to direct me to somewhere
where I *might* find the answer I am looking for, especially if it
requires me to purchase some hardware and/or software to view the
answer. It wasn't particularly how the equipment operates, more how
it calculates this average. I can't imagine there is anything of
commercial value in the algorithms used, so I would like to restate
my original request. If your department doesn't know how this is
calculated, could you get this information from the private company
that does know? And also assurances/audits on the validity of the
algorithms used?

Yours sincerely,