i don't think low tree branches are considered as official
height restrictions
low dangling or protruding tree branches are supposed to be
trimmed periodically by the authorities!! otherwise it may pose a
hazard to vehicles and even to pedestrians crossing the road...who
knows when they will detach and drop off during heavy showers or
windy days
height restricted zones will be indicated by a signboard that
legally prohibits a certain height...like those multi storey
carparks or changi airport basement
it's a myth to deduce that depot road restricts DDs due to tree
branches, it's only hearsay and rumours, it's not official
there are only two ways by which you can enter depot road,
either via (southbound) Henderson Road or Alexandra Road
i don't see any height restriction signs just before entry to
depot road to prohibit any kind of vehicles
in fact i've seen off-service DDs on depot road before..very
rare..but it happened
i bet the DDs on Depot Road became open top

!