(25 Jan 2018, 4:28 pm)glen1234 wrote Hi i seen 2 zone on 13 service just now all so i have the seen zone on service 12 a couple time why is that.

There was a Dots E300 on 13 this afternoon too. I guess they get allocated when they're short. The 13 also gets anything that is poorly or is due in for inspection as it passes the depot gates so is easy to get buses off. Equally they'll be replaced with whatever is fixed or off inspection in the depot.