The Road Traffic Statistics website contains traffic census data from every traffic census point in Great Britain, as compiled by the Department for Transport. Each page presents the data in full numerical form as well as handy graphs and pie charts.
You can contact the administrator of this website by email at 'admin{at}roadtrafficstats.uk' (making the obvious substitution to turn that into a valid email address).
For those that care abut such things, this site is built on an open source platform using Linux, Apache, PHP and MariaDB. It runs entirely on recycled electrons. No animals were harmed in the making of this website, but large numbers of coffee beans gave their lives for the cause.