I was told from quite a few railway workmates over time that it was intended to be upgraded to four track by the LMS before WW2, however apparently WW2 started to kick off before it was started. If that is true or not I don't know 100%, but I will say it needs it.
The whole Coventry to Bham New st corridor is a right bottleneck. The LM stoppers are also quite badly timed that a slight delay seems to wreck everything. Also the whole concept of looping a service to allow a faster service to get past seems a concept that Network Rail bobbys (Or at least there supervisors) can't grasp these days. I've left BHam right time loads only to catch up with the local at anywhere between Berkswell at best to Adderley park at worst. Usually incurring a good delay with following it all the way to Coventry & then missing my "slot" on the WCML at Rugby & having to wait & then follow another VHF service to Euston getting held by it's stopping pattern rather than getting a good run. Chuck a freight working or W&SR in the mix & it really goes bad for anychance of getting there right time. Coming back is even worse. Euston to Coventry south at proper speeds, get to Cov & your once high speed service becomes more akin to a class 9 freight of old. Chugging along at around 25mph following red,single yellow, red, single yellow etc etc all the way to Brum.