There's a couple of crossover scanario here..
1. Use buses from 961 985 or 980
2. Crossover from 188E (963E buses do 530)
2nd method waste more diesel.
I think it's more of 2nd method? Lolx.. Saw & Co. loves to
waste more fuel... 1st is Service 61 (WLDEP to Bt Batok
Interchange, every single day), now is this Premiun 546?