(a) The unit of sampling and measurement you have chosen for your sampling plan determines the expansion factor you should use.
(b) While you could have chosen any unit of sampling measurement for your sampling plan, it most likely is in one-way bus trips or in round-trip bus trips.
(c) The following assumes that your sampling plan is based on one-way bus trips.
(d) For estimating annual total PMT and UPT:
(1) Use annual total one-way bus trips if your sampling plan is not based on grouping.
(2) Use annual total one-way bus trips by group if your sampling plan is based on grouping.
(e) For estimating average daily PMT and UPT by type of service days, use annual total one-way bus trips by type of service days.