The good news is that the tow path through Edgbaston tunnel is going to be widened. With the existing tow path barely wider than the handlebars on a bike, and rough brick on one side and and an open fence on the other, this has long been a cause of many problems, including injuries.
The bad news is that the scheduled closure will be from 22nd January 2018 to 16th March 2018 (NB - the dates have changed again), and the alternatives for cycling on road are heavily trafficked (of course) and hilly.