I appreciate this probably isn't Nexus fault, but couldn't find anywhere more appropriate. Feel free to move if there is!

Driving over the crossing in to the Sunderland portion of Fencehouses tonight, I noticed a set of temporary lights rendering two stops out of action. The Houghton bound stop being one.
As per the norm, a temporary stop had been 'installed'.

What caught my attention, was that it wasn't a Nexus flag.
I recognised the italicised 't' and purple colouring behind it, but can't think which LA/PTE it belongs to.
I'm guessing the contractors had brought it with them.
With driving and being caught in a flow of traffic, I couldn't get a snap unfortunately.

Any ideas who the 't' is?