Was this an acceptable undertake?

[joelpython]

I’ve been driving for five years. I don’t do much motorway driving.

I was driving on a stretch of the M27 “smart” motorway last week. I was in lane 1 with no other cars in front of me in that lane for a long distance. There was no-one behind me breathing down my neck. There was a lorry in lane 2 doing about 60mph. I accelerated to 70mph to get past the lorry. I realised this was an undertake, but I didn’t want to be in his blind spot.

I’m curious as to whether this was an acceptable example of an undertake?

[joelpython]

Thank you for the interesting replies. I think the lorry driver had plenty of time and space to move to L1 before I got to him if he’d wanted to. It could be that he was staying in L2 because he knew that L1 became the exit slip road (J9) in about two miles.

I didn’t want to slow down and hang back because then I would have been doing about 55mph on a motorway, which sounds dangerous to me on an unobstructed stretch.