SMRT had made its cross border service 950 WAB. Sooner or later
I believe SBST would also make 160 and 170 WAB as
well... 
Maybe in 2019 before the deadline in 2020.I think SBS Transit
don`t want to make 160/170 as a WAB service first since they are
many other services that deserved to be WAB service since they are
old people taking this service