(07 Sep 2021, 9:35 am)Train8261 wrote What can you really class as Express. Like I only think the X9/X10 are actually Express routes
If we take the X21 at face value, I'd consider it an express route as it is an 'Express 21', being considerably faster than the regular 21.
Additionally, looking at the Durham to Bishop/West Auckland section of the route, it is basically the way you would drive anyway.
However, looking at the route as a whole, it obviously doesn't go the quickest way because it's quicker to get to Newcastle going to Bowburn and then straight up the A1.
It does however go the most 'direct' route in terms of distance, being about 4 miles shorter.