§ 75.05 – What steps should I follow to calculate sample averages?

(a)    Aggregate the field sample data to the individual service units in your sample after you have identified and corrected any errors in the data. 

(b)   If the unit of sampling and measurement for your sampling plan is one-way car trips, sum these quantities over individual one-way car trips in the sample to get sample totals:

(1)   for the entire sample,

(2)   by type of service days,

(3)   by weekday time period if your service is commuter rail (CR), heavy rail (HR), or light rail (LR), and

(4)   by group if your sampling plan is based on service grouping.

(c)    Count the number of one-way car trips in the sample:

(1)   for the entire sample,

(2)   by type of service days,

(3)   by weekday time period if your service is commuter rail (CR), heavy rail (HR), or light rail (LR), and

(4)   by group if your sampling plan is based on service grouping.

(d)   Divide sample totals by the number of one-way car trips for the entire sample, by type of service days, by weekday time period if applicable, or by service group if applicable.