II.off [美 ɔf, ɑf, 英 ɒf]副off often appears as the second element of certain verb structures in English (break off, pay off, take off, etc). For translations, see the relevant verb entry (break, pay, take, etc).
I.on [美 ɑn, ɔn, 英 ɒn]介词on often appears as the second element of certain verb structures in English (count on, lay on, sign on, etc). For translations, see the relevant verb entry (count, lay, sign, etc).
The combination of off-board fare collection, three door loading, and level boarding onto the buses results in faster boarding and less time spent at each stop.