(3 hours ago)F114TML wrote Wasn't most of that meant to be done in the upgrade works that happened about 10 years ago?

I think you are right. When the superstore was added on the south side of the site, I thought the planning permission required a potential bus-only through route, and that does seem to exist. However, there was no other element of bus priority to protect the buses from becoming entangled in congestion in the car park (restricting the rate at which traffic is able to leave a site like this is typically a highway design requirement, to avoid swamping the local roads outside the site). 

For services 22, X6 and X10 that approach from the east and leave from the east, a circuit of the site will take a couple of minutes longer than now in normal, fairly uncongested circumstances. Given that the operating cycles for those services don't have that time to spare, I think that was why everything has continued to use the original stop, entering and leaving at the east end. (They all suffer badly on the relatively few peak days, of course.)

I'm pretty sure the main motivation for the latest scheme is nothing to do with benefitting buses - it's to speed the passage of car traffic (At present, traffic exiting gives way to turning buses.) An ideal scheme for bus users would have retained the ability for relevant buses to operate as now, ideally with bus-only lanes to protect them from car congestion.

But I'm really puzzled why there is so much public funding being put into this - is there any funding from the private sector? None of the roads are public highway. The bus stop improvements in the site surely would cost at most medium hundreds of thousands - its basically only 3 new big bus shelters. Vast majority of the cost will be the widening of the (privately-owned) approach road. Perhaps a whiff of Tees Valley affairs in this?