Not sure it would be quicker even with the traffic remember the services also serve the central station and people do get on and off there so by the time you traveled along Centre Link, went over the swing bridge and then doubled back up Forth Bank (which can be just as bad) then you've saved nothing at all. Outside of traffic it's much much longer.

Centrelink was a waste of money imo as it's a bypass of Gateshead when the buses go to Gateshead and serves nothing along the route to warrant the longer route and any bus going to Newcastle will use the Redheugh Bridge.

If traffic was such an issue it would be quicker for the buses to double back on thereself and use the Scotswood Bridge and go along Scotswood Road which rarely has traffic issues. It's negligible as it is anyway.