Variable Hypothesized relationship Source
Service area (urbanized area) characteristics
Population Positive coefficient: Agencies serving larger populations will adopt earlier because they have more potential riders. United States Census Bureau via tidycensus
Number of transit agencies Positive coefficient: Agencies in areas with more transit agencies will adopt earlier because they are more closely networked with peer agencies [@169804]. NTD
Percent renter households Positive coefficient: Agencies in areas with more renters will adopt earlier because they serve a higher turnover population and more riders who are unfamiliar with their systems. United States Census Bureau via tidycensus
Agency characteristics
Annual vehicle revenue distance Positive coefficient: Agencies with more vehicle revenue distance will adopt earlier because they are larger [@169804]. NTD
Annual ridership Positive coefficient: Agencies with higher ridership will adopt earlier because they have more customers who would benefit from it. NTD
Organization type Positive coefficient for independent agencies: Independent agencies and authorities will adopt earlier [@169802] NTD
Overhead Positive coefficient: Agencies with a greater share of operating costs allocated to general administration will adopt earlier because they have greater organizational slack [@169804]. Calculated from NTD as total salary and fringe benefits for general administration divided by total operation expenses.
Farebox recovery Positive coefficient: Agencies with a greater reliance on farebox revenue for their operating expenses will adopt earlier because of potential gains from increased ridership. Calculated from NTD as fare revenue divided by operating expenses
Local vehicle revenue distance share Negative coefficient: Agencies that offer a lower share of the total service in their area have a greater need to coordinate with other agencies and will have stronger interagency relationships [@169804]. Calculated from NTD as annual vehicle revenue distance divided by total annual vehicle revenue distance for all agencies in the urbanized area
Context characteristics
Years since publication of GTFS standard Positive coefficient: Agencies will have had time to learn about GTFS, and cost-saving software tools for generating and testing GTFS feeds will have been developed. Calculated for each year.
GTFS market penetration Positive coefficient: Agencies will have observed lessons learned from prior adopters. Calculated from adoption dates.