M25 avoinding Chiswick Roundabout?

I have to get onto the M25 tonight from North West London, and I'm trying to avoid the Chiswick roundabout and the two hours of congestion which is inevitable round there. I'm sure there's a way onto the M25 from the M40, but I don't have a road map to hand.

Am I right, is there a way on to the M25 via the M40? If so what connection is it? I'll be heading south.

Many thanks

Yes, the A40 turns into the M40 and crosses the M25. Don,t know the connection, but you won,t miss it it is a big connection well sign posted.

maps.google.co.uk/?ie=UTF8&ll=51.560851, 0.43808&spn=0.18569,0.462799&z=11&om=1maps.google.co.uk/?ie=UTF8&ll=51.560851, 0.43808&spn=0.18569,0.462799&z=11&om=1">maps.google.co.uk/?ie=utf8&amp,ll=51..

The path planner at rac.co.uk/web/routeplanner/?&lid=leftNav&lpos=routeplannerrac.co.uk/web/routeplanner/?&lid=leftNav&lpos=routeplanner">rac.co.uk/web/routeplanner/?&amp,. is good.

Yeah there's, but unless things changed considerably since I was last there, you will get about as much congestion heading out of London on the A 40..

The M25 connection is shortly after the A40 turns into the M40 as it passes over the Denham roundabout. be sure you stay well to the left and be cautious because you must move over and merge with lane one which is full of traffic coming up off the Denham roundabout and onto the motorway.

The connection you need is J15/4B. Leave north west London via the A40. This turns into the M40 which will cross the M25.

The connection is M25 Jct 16 and M40 Jct 1a.

You do not say where you have to go from the M25,
but if your in North West london it is simpler to get on the A40 and cross down south via A312 signed to Yeading & Hayes to connection three of M4. it's then a short distance to the M25.
You then avoid the bulk of the Heathrow traffic.
It is the path I use on a regular basis to Gatwick and takes approx 1and half hours door to door from NW6 without a panic.

Yep just drive up the M40. The M25 is BIG..you will not miss it.