In some instances, N/A values are returned for the Average Time to Work variable in the American Community Survey (ACS) Population Summary report when the report is run for a small site such as for address points within five miles radii. This is because the ACS data is not available for most block groups, and so the data cannot be displayed. The available data is not reliable enough by Esri standards for mapping or reports for that areas of the country, and hence N/A values are displayed for the Average Time to Work variable in the report as shown in the image below:
The data used to calculate the Average Time to Work variable is available within the ACS Population Summary report, but not at all geographic levels. Sufficient data is available for larger geographic areas. For example, if the ACS Population Summary report is run on an entire state, the Average Time to Work variable can be viewed because the data is reliable enough at this sampled size, and meets the accuracy standards.