When I have the misfortune of using any of the motorway network through the Midlands, the traffic is vile. Just needs a minor shunt and you can sit motionless for an hour... Is this an event that you can't miss, or is turning up late only a minor inconvenience?
Where are you actually headed? Do you mean 'have to be at the Jubilee Line station at CW' at 1100? Or somewhere else on the Isle of Dogs? In which case there might be more time needed. Sorry, I know this isn't what you wanted to hear, but the plan as outlined seems to have some risk of not being achievable in time you've allowed.

On Sun, Nov 24, 2013 at 01:14:02AM +0000, Paul Corfield wrote:
On Sat, 23 Nov 2013 20:20:23 +0100, juliejonesy
wrote:
We will be travelling from Liverpool to London (Canary Wharf) on Tuesday
by minibus. We will be leaving school at 6am and we need to arrive in
Canary Wharf by 11am.
I am no expert on the motorways but is 4 hours enough time to get from
Liverpool to Stanmore allowing for the inevitable rush hour delays you
will hit at some point on your journey?

Should be OK provided that you leave at 6, and that 6 isn't really just
a vague suggestion to the children and their parents that they might
like to vaguely consider possibly getting out of bed by 6.

Use the M6 Toll, as the M6 through Birmingham has horrible road works at
the moment.

Don't all motorways crawl to
a halt during the AM peak period

No.

--
David Cantrell | Godless Liberal Elitist

Fashion label: n: a liferaft for personalities
which lack intrinsic buoyancy