Herford Street is one of the worst streets of any city centre of the UK, and I've seen some bad ones. Why spend money on opening it up to broadgate rather than spend money on demolishing the whole thing and starting again ?
That's exactly what's going to happen. The link was opened up ahead of the wholesale redevelopment. Most units are on short-term lease and there will be CPOs issued in the near future. One side of Hertford Street will be flattened and rebuilt, the roof will go and the street will be returned to a single level. Not before time, it is grim.