I'm of the opinion that it just needs to be allowed to die and instead use some of the money saved to build another entrance towards the Forbidden Valley side somewhere. When the Grand Entrance was first installed there was no Forbidden Valley or Haunted House so it made sense that you'd have to travel via the monorail or something when more parking was needed to get over to the main entrance near to where many of the rides were. This is just not the case any more though and it would be totally acceptable to enter somewhere over the FV side and be able to start enjoying your day straight away.
It makes little sense to have to travel around the perimeter of the site passing lots of rides either walking or using the monorail (passing over rides in the case of the monorail). You could then have 2 entrances and Towers Street could pretty much stay as it is but with less staff needed at that entrance. Parking could then be spread across all areas (coaches would obviously be forced to still use the coach park).