The last 2 days of the Hampton Court flower show are on Saturday 9 and Sunday 10 July 2011. This event can cause local traffic to become grid locked.
The flower show is open from 10 am until 7:30 pm so I wouldn’t expect there to be a problem if arriving at AQSC by 9:30 but it would be wise to avoid Hampton Court and maybe Sunbury Cross. Walton Bridge can be an alternative to Hampton Court bridge.
Hampton Court Flower Show Traffic Notes Updated 5Jul2011
If coming from the M25 I suggest exit at Junction 13 (A30) rather than the M3, then take the A308 at the next exit. The map below shows a couple of alternative highlighted routes off the A308 to avoid any possible jam at Sunbury Cross.
Before Sunbury Cross there is a Tesco on the right; if you noticed a jam ahead you could escape into Tesco to take an alternative route.