Nearly killed a motorcyclist this morning

[DaveCWK]

Passing a line of cars in lane 3 on the M25 near Heathrow. Go to pull in as normal, and a bike has appeared in my nearside blind spot.
Only reason I didn’t have him off was his quick reach for the horn. I get the idea of using a bike to beat the traffic when it snarls up, but to power up the inside of live lanes of twilight bleary-eyed rush hour traffic travelling in the rain at 50mph you must have a death wish.
Be careful out there everyone. And always think ‘Does that car know I’m here’

[DaveCWK]

N Dentressangle said:

How did the bike just 'appear'?

I'm guessing they filtered between lanes 1 and 2 before positioning themselves in lane 2 just as I was pulling in. Yes I looked over my shoulder, no I didn't see them.

[DaveCWK]

Bluebarge said:

If the legal limit is 70 and traffic is heavy such that L3 is travelling more slowly than L2 or L1 there is no obligation on the traffic in L2 to slow down to match L3. The OP stated he was doing 50mph in L3. So, bike could have overtaken blue car in L2 by moving into L3 and returned to L2 and then been travelling more quickly than the car in L3 - all legal.

The lane I was in, L3, was trvelling faster than L1/2, hence the overtaking.
Having thought about it the only way the biker got where he was was via undertaking/filtering between L1/L2 and then 'joining' L2 in front of the car I was overtaking at the point I was pulling in, such that I didn't see him do so.
After I was given the stare of death they proceeded to speed off filtering/weaving between the traffic in L3/4 so it's a fair guess that's what they were doing beforehand.

I didn't create the thread as a rant against bikes. we all take liberties, just hoped it might prompt someone to apply a little consideration before doing so.