Safe Speed Forums

I'm sure this must have been a previous subject, but could someone please tell me the reason the A 13 from the Blackwall tunnel out towards Essex is now a 40 limit? I was very nearly a bike/ lorry sandwich in which I was the meat. Three of us trying desperately not to break the limit but not wanting to block the carriageway. Eventually, out of frustration, the outer lorry cut in , I had to break hard and nearly went under the wheels of the inside lorry.
On my return journey I went down A124 Barking Road. I felt safer, relaxed and wasn't in fear for my licence for some minor infraction of the law.
The loonies are surely in charge of the asylum!