(05 Sep 2014, 6:57 pm)nk55 wrote Not forgetting the 39 also operates down chester road.
It does indeed.
But like the other ones Michael mentioned, it diverges before reaching the faster, dualled section of the A183, coming away from Sunderland.
Granted the stops between the Grindon Mill and Hastings Hill are used, but not enough to justify the frequency it gets.
They probably have the frequency, by virtue of living on a main route into/out of Sunderland.