Well here's the info from some UK colleagues:
It is apparently really heavy from 16.30 - 18.30 on weekdays going out.
And this is a bit more specific:
Quote:It is always busy but travelling West bound from
Swindon (J.15)after 06.30 it builds steadily in volume, junction by
junction, until around 07.00 at Junc 12 onward into London you are in
solid traffic, sometimes moving often hardly at all, up until 10.00 then
it subsides but not by much.
Eastbound out of London, again busy/heavy most of the day and especially
from 15.00 hours onward. Friday afternoon the rush out of London starts
at midday and is busy through to 21.00 hours.
Hot spots around Heathrow and M.25 junctions, Junctions 8/9 (A.4
Maidenhead Henley-on-Thames) - and Junction 11 (Reading).
Sounds like your boss was determined to beat the traffic.