they dont tap when exit, is probably they have Monthly
Concession Pass.. no need to tap when alighting.. Also, once u tap
at the entrance, the full fare is deducted, even if u dont tap when
u exit, hence stories of overcharging.. the Exit Reader doesnt
serve much purpose except for adult fares, unless again, its a flat
fare service like feeder bus.
Every ENTRY tap is equals to one deduction though..