M5 NB at M42 split

Can anyone enlighten me, why does the M5 go from 2 lanes to 1 lane there only for it to go back to 2 lanes less than 1/4 mile further on? All it does is create a massive queue down the M5 everyday as everyone fights to get on that 1 northbound lane.

think its a temporary measure so people go around the m42 instead of going over the oldbury viaduct roadworks (maybe)

Thats what all the local papers/radio were saying when it was put in. Its nearly 20 mile longer though so most people now think, its about the same either way and just carry on up the m5.

Sent from my SM-G903F using Tapatalk