Outer(ish) London traffic on a tube strike day - much worse?

[norman156]

I'll be heading straight up the A406 North Circular and then A41/A1 out of London from Ealing straight after work, anyone have any idea how much worse these roads are on a tube strike day, or is there not much difference? Really wouldn't be sure if many people would switch to a car instead of the underground on a day like today or not.

Thanks in advance!