What's happening on the A40?

[motco]

There's more BiB on the A40 just outside Beaconsfield Old Town than there are in Downing Street when Dubya's here! There's a "safety" camera van on the A355 just off the M40 - no warning signs - and dozens of BiB pulling cars seemingly at random as they enter the town itself. A Honda Concerto legged it just as I came through an hour ago - last seen haring west along the A40 towards High Wycombe out of the Beaconsfield Old Town with a jam sandwich and a BiB bike in hot pursuit.

So - what's happening then?