afaik the current DDs i took the Olympians never had any sort of
glass at the staircase area. Not sure about the Tridents.
All along it was frosted glass panel because of design (cant
remember the actual reason why)...if it was transparent glass the
first B9TL would have recieved complaints from ladies. Neither is
CDGE that odd to put transparent glass at staircase to purposely
free show.
I don't ever recall clear glass panels on the staircases of our
double-deck buses. Up till the Tridents and the Volvo Super
Olympians (sans SBS 9889U), all of our double-deck buses use
plastic paneling for the staircases; SBS 9889U (the ComfortDelgro
bodywork prototype) and the B9TLs all had frosted glass if I
remember correctly. The fact that SBS 9889U predate the B9TLs, and
the fact that I took it once and noticed the frosted glass before
the B9TLs came in, suggest that the frosted glass had been there
all along.
Edit: found it on tintinspartan's YouTube page: a video
of him riding SBS 9889U. This was in the middle of last year,
and the frosted glass is already there (go to about 3:24 in the
video; you see it best at about 4:30 when he pans over to the
staircase). All credits for the video go to tintinspartan.
