After using the Create TOPS interface, the user can move on to utilize other interfaces in the Sample Adequacy tab. Potential Samples () is one available sample interface. This interface is used to add samples to meet FHWA requirements.

Filter

Top Filters

The user can search by stratum on the Potential Samples interface through the Volume Group, Functional System, and Urban Code filters at the top of the Potential Samples interface. After selecting values for the filters, the user can click the “Find Now” button to have a list of segments appear in the table. The resulting segments include unsampled TOPS locations and existing sample sections.

When accessing Potential Samples through Check Adequacy or Expansion Factors, the filters will be pre-populated to reflect the selected stratum. Check Adequacy will connect to this interface through the linked, first number on each cell; this process is described in more detail here.

Data Completeness Filters

Data Completeness provides additional filters in this interface. This portion contains two checkboxes, a textbox, and a link that all help with narrowing the information on the table. The function of these elements are described in this User Guide article.

Potential Sample Table

The Potential Sample Table will be populated with TOPS sections within the specified Volume Group, Functional System, and Urban Code selected. Users can add samples in two ways: manual and random selection. 

Manually Add Samples

To manually add samples:

1. Check the checkbox in the first column on the desired segment.
   • Checkboxes will not be present for segments already designated as samples.
   • Segments that appear red in the table do not meet AADT criteria specified in the Data Completeness section.
   • Segments that appear orange in the table do not meet segment length restrictions set by the FHWA.
   • The “Completeness” column can be used to find the segments with the most amount of data items that exist on a segment. The number in this column specifies how many data items exist (1st number) versus (/) the total amount of data items in the selected data table (2nd number). Clicking on the completeness field will display a popup showing a list of data items that exist.
2. Add a new sample ID by clicking the Samples column and entering a value in the textbox.
   • If no sample ID is provided before saving, one will be generated automatically based on the current year and zero-padded to support a 12-digit format.
3. After selecting all desired segments, click the “Add Samples” button to add the new samples to the samples table and data table.
   • To apply changes to the data source, check the “Save to Source” checkbox before clicking “Add Samples.”

Randomly Add Samples

To randomly select samples:

1. Click the “Random Select” button to open the Random Samples interface.
2. Specify the number of samples to be created by entering a value in the “Number to Randomly Select” textbox.
3. Check the “Exclude Segments not meeting AADT criteria” and “Exclude Segments not meeting length restrictions” checkboxes if desired.
   
   • Check the “Exclude Segments not meeting AADT criteria” checkbox to prevent from randomly selecting a sample that does meet the criteria specified in the Potential Samples Data Completeness section. The checkbox will be disabled in this interface if the “AADT not within…” checkbox is not checked in the Data Completeness section.
   • Check the “Exclude Segments not meeting length restrictions” checkbox to prevent samples from being randomly selected that do not meet length restrictions set by the FHWA.
4. After all desired parameters have been set, click the “Select Samples” button to randomly select the provided number of samples.
   • These samples will be given a generated sample ID based on the current year and zero-padded to support a 12-digit format.
5. Finish adding the samples to the sample table and data table by clicking the “Add Samples” button on the Potential Samples interface.
   • To apply changes to the data source, check the “Save to Source” checkbox before clicking “Add Samples.”

Sample Table

Below the data table, in the “Sample Table” section, the number of required samples, existing samples, samples that are needed to meet requirements, and total samples can be found. The number of selected samples and total number of samples will increase or decrease by selecting segments to sample using either method above.