To echo the comments from elsewhere, that road has been blocked off for a while now.
Certainly since construction.

Not 100% sure why it has never opened fully, although I imagine there are political motives somewhere down the line in regard - similar examples have existed with the landowner/developer and getting agreement from the local authority to adopt it.
Whether that is the case in this example, who knows?

If I remember right, bus stop layby's have been constructed.