258 no need full DD...
I agree. In fact, when 258 was launched two years ago, I was
expecting them to deploy Mercedes-Benz Citaro buses, so I could say
"I take Mercedes to school everyday".
Based on my observations on 258 loading, I would say that
single-decker buses is enough to meet the demand, even at peak
hour, especially after it takes over 256's quiet section and loop
outside Boon Lay MRT station.
Ridership on 258 will fall. But what remains is that group of
people who would continue to take 258 at Jurong West to connect to
their buses at Joo Koon Bus Interchange. The bus would be very
packed in the morning at around 6am, but during other hours, it
should be quite empty.
Perhaps a higher frequency during morning peak hours would help.
But generally, it would be more appropriate for 258 to have
single-decker buses, instead of double-decker buses. No need for
double-decker buses, actually.
Thus, I agree that 258 does not need to have full DD. In fact,
it can do well with full SD, if the frequency is slightly higher
during morning peak hours at around 6am.