Box A: How are Modes Defined?
The Intermodal Passenger Connectivity Database categorizes scheduled passenger transportation services by five major mode categories and a total of 11 subcategories. The major categories and their sub-categories are:
| Mode | Sub-categories |
|---|---|
| Air | Air service |
| Bus | Intercity bus |
| Transit bus | |
| Code share bus | |
| Supplemental bus | |
| Ferry | Intercity ferry |
| Transit ferry | |
| Standard rail | Commuter rail |
| Intercity rail | |
| Transit rail | Heavy rail |
| Light rail |
SOURCE: U.S. Department of Transportation, Research and Innovative Technology Administration, Bureau of Transportation Statistics.
Most of the analyses presented in this report discuss connections to the major mode categories shown above. However, the report also examines connections between intercity and transit modes. The intercity and transit modes include the following sub-categories of service:
| Intercity | Transit |
|---|---|
| Air service | Transit bus |
| Intercity bus | Code Share bus |
| Code share bus | Supplemental bus |
| Supplemental bus | Transit ferry |
| Intercity ferry | Commuter rail |
| Intercity rail | Heavy rail |
| Light rail |
NOTE: Code share and supplemental bus may provide intercity or transit service depending upon whether it code-shares with, or supplements service for, an intercity mode or a transit mode.