To Acx1688,
Eh, sv36 was not introduced from Bukit Merah, it's a loop
between Changi Airport and Tomlinson Rd[loop service].
sv36 and sv16 serves different segments of the East side although
their routes are complimentary along Orchard Rd and there is a
demand for the different routes. Both svs cant use DD cause of
height restrictions at Changi Airport & Stadium Rd/Nicoll
Highway Tunnel so chances are slim...
Someone messaged me privately just now and pointed out this
paragraph written by tranquilice on 12 February 2004:
Service 16 "originally" operated
between Bt Merah and Marine Parade. In 1993, services 31 (Tampines
- Stadium Blvd) and 149 (Toa Payoh - Changi Airport) were merged.
As a result, service 16 was extended to the airport to cover
service 149 route from Marine Parade to the airport. Service 390
(Changi Airport - Tomlinson Rd) was withdrawn with service 16 as
the alternative service. However, soon, service 390 passengers were
complaining that with the amendment, they had to take service 16 to
the airport which resulted in a longer travelling time. The press
published the complaint and this "forced" SBST to introduce
one-directional-peak-hours service 16E (Semi-express between Bt
Merah - Changi Airport) not long after, which plied express along
ECP, Rochor Rd/Ophir Rd, Beach Rd between the airport and City Hall
MRT. In Dec 1997, service 16E was re-numbered service 36
with route and operating hours un-changed. Then in Sep
1998, service 36 route was amended to become the route today and
changed its operation hours to a full day service, and service 16
route was shortened to Marine Parade on the same day.
Service 36 did ply Bt Merah - Changi Airport from Dec 1997
to Sep 1998. During that period, it duplicated service 16 between
Bt Merah interchange and Stamford Rd/Bras Basah Rd during the peak
hours. Before Dec 1997, service 36 is numbered service
16E.
For more information on service 36 (Bt Merah - Changi
Airport), please check the 1998 Transitlink
guide.
Actually I am a bit stunned that: 1. tranquilice knows his bus
history like no one's business; and 2. that this "someone" (who
prefers not to be named) can point out a paragraph that was written
10 months ago! 
I remember taking Svc 36 from Bukit Merah, but I am quite certain I
wouldn't be able to recount the entangled history of 16/16E/36/390.
Perhaps someone brought up this subject eons ago.