§ 43.03 – What period-based ready-to-use sampling plans are available for bus services?

(a)    Table 43.03 shows the available ready-to-use sampling plans for bus services, including bus (MB), commuter bus (CB), bus rapid transit (RB), and trolleybus (TB). 

Table 43.03.  Period-Based Ready-to-Use Sampling Plans for Bus Services

Sampling Frequency

Sample Size for Period and Year

One-Way Trips

Round Trips

Reporting 100% UPT

(APTL Option)

Not Reporting 100% UPT

(Base Option)

Reporting 100% UPT

(APTL Option)

Not Reporting 100% UPT

(Base Option)

With Route Grouping

Without Route Grouping

With Route Grouping

Without Route Grouping

(1)

(2)

(3)

(4)

(5)

(6)

Quarterly

Trips for a Quarter

52

78

138

39

59

103

Total Sample Size for Year

208

312

552

156

236

412

Monthly

Trips for a Month

18

27

46

13

20

35

Total Sample Size for Year

216

324

552

156

240

420

Weekly

Trips for a Week

4

6

11

3

5

8

Total Sample Size for Year

208

312

572

156

260

416

(b)    Sampling plans are provided separately for one-way trips and round trips. 

(c)   The number of one-way trips in a sampling plan based on round trips is about 50% greater than the number of one-way trips in a sampling plan based on one-way trips.  A sampling plan based on round trips requires a larger number of one-way trips because the pair of one-way trips making up a round trip are not selected randomly or independently.

(d)    If you choose the base option:

(1)   use column (3) to find the sample size in one-way trips, and

(2)   use column (6) to find the sample size in round trips.

(e)   If you choose the APTL option, you may choose one of two options:

(1)   With Route Grouping – Use column (1) to find the sample size in one-way trips and column (4) to find the sample size in round trips.  In using this option, you must divide your routes into two groups on the basis of route length and do sampling and estimation separately for each group.  For example, if you operate 10 routes, put the 5 routes with the shortest route distances in the group of short routes and the other 5 routes in the group of long routes. 

(2)   Without Route Grouping – If you prefer not to deal with grouping your routes, use column (2) to find the sample size in one-way trips and use column (5) to find the sample size in round trips.