Why must it be Enviro500?
First of all, I never said it MUST be
Enviro500. All I asked was the possibility. Also,
1) Why must it NOT be
Enviro500? There's already a Citaro, 2 OCs and a lot of
O405 buses which will deregister in due time, and perhaps an
Enviro500 or two can replace them. Sure, it's more feasible to
deploy A22, but I was just asking about the height
restriction.
Also,
2) While the frequency isn't too bad, more tourists may or may
not take RWS8 over the never-not-crowded Sentosa Express, and we
need to assure them that they have a seat like 49 having DDs even
though demand is not exactly that high. Especially the holiday
season when everyone wants to go....
So back to my question, can a Enviro500 bus ply RWS8, RWS88 and
188R?
What I meant was of all the choices(with SDs), why did you
choose a DD? Is it because of the demand or what?
And since you mentioned that you never said it must be
Enviro500, why you mentioned must it NOT be
Enviro500? 
I'm not so sure about the demands but I don't think it's needed for everyone to
have a seat as they will be alighting very soon..even people are
packed on the Sentosa Monorail during
PH/Weekends/Holiday..
Plus you mentioned the may or may not take RWS8, so what's the
purpose of deploying these Enviro? A little wastage of
resources...