(07 Mar 2015, 10:30 pm)Dan wrote Shouldn't be having as big an affect as it seems to be having, and of course this diversion hasn't been in place for months (or years) on end. See aureolin's earlier post.
Go North East's services are running fine, as the diversion in Chester-le-Street only really adds about two minutes to the normal timetabled journey. Easily made up when you've got enough recovery time built into the timing points or layover time at each end, which, as already established, the X2/X12 has very little.
I would e-mail Arriva Customer Services to address my issues with regards to timekeeping and lack of layover, but quite frankly, it's not worth the 30-day wait for a response. Quite surprising Arriva isn't more proactive on a route which they face strong competition on...
In fairness the 21 the short journeys don't do the diversion the X2 does (although leaves from a different stop to normal) and the Durham 21's have lots of layover in Durham Bus Station often see a 21 leave then see another one arrive. Although the X21 seems to cope fine and GNE can send another bus out from Bishop Bus Station if it looks like the X21 will arrive back late, Arriva can't really do this in Middlesbrough Bus Station with the X12/X2 especially on Belmont operated journeys.
I imagine Stockton's journeys seem to go more smoothly as they use Pulsar's on their journeys which handle the route well while the Gemini's are pretty slow especially on hills on the X12 route. Also Stockton don't change drivers in Durham Bus Station like Belmont depot does on journeys leaving as the X2 and journeys leaving as the X12.
Other than that all I can say is possibly traffic related issues especially in the Durham area at times and how many stops it actually makes between Durham and Coxhoe.