Answer: Those that a bus driver need to possess!
Lianhe Zaobao 2010-01-19's report by 李静仪:
(Currently, SBS has 3000 buses and employs nearly 5500 drivers, of which 8% are PRCian, 26.5% Malaysians, 27.5% Singapore PR and the remaining 38% Singapore citizens.)
We approve more than 1500 PR applications to bus drivers.
We have more than 1500 PRs working as bus drivers!
They are all ex-foreign talents, current talented PR and future talented new citizens.
We need to import such talented new citizens because Singaporeans are not talented enough! For example, are you talented enough to know how to drive a bus? Nah, I don't think so. You are simply stupid enough to serve NS to defend these talented new citizens!