Folks, think about private cars. If drivers can use the same key for ignition, door lock or even emergency exit lock, it is much more convenient like routine process. It is in fact less chances to experience technical failure when compare to smart card. (and I am quite sure it is expensive to design the whole database)
Of course, there is still something can be improved.
My idea is keep using the allocated key by company, whereas:
1. Modify the design of the system right now: Both emergency exit and passenger doors are locked after driver finishes a whole day service. (Simply like a car)
2. Modify a bit for the key design, only the genuine one can control every single bus.
3. Returning the genuine key is compulsory for every driver after work.
Hopefully no one can take the key away and drive the buses illegally.
PS: sorry for poor english or grammatical mistakes but I just cant type chinese on this computer.