I think it has to be a two pronged approach though rather than just 'banning' HGV's between those hours - don't forget many businesses rely on their morning deliveries from these lorries. Banning them from making morning deliveries because they can't get out of London before the 'ban' (due to the traffic) is the wrong thing to do, it's reactive, not proactive
How else do people expect things to be delivered, where I work we have terrible problems already delivering stuff to London due to different licence compliance (for the drivers ) along with emissions compliance for the lorries and a host of other stuff not required anywhere else in the UK/continent.
Yes, it's cheaper to deliver things to Holland than London! It 'costs' around the same to send a lorry to the north of Scotland!
I'm sure little Charles and Amelia really could take the bus/tube/cycle to school rather than sitting in their fathers Range Rover Sport cluttering up the road. Can't complain too much as it's the same here, half term week the roads are 'working as intended' with traffic flowing, rest of the time total gridlock for 2+ hours! Grrr, sorry to go on but it's a big bug bear of mine!
I'm off to now join them as I drove to work today...