Determine if/how to support the extension modes (GTFS) and NeTEx submodes

[brylie]

We want to align the project with OpenTripPlanner (OTP) and support carbon estimation for common transport modes. OTP developers are in discernment about how to align with GTFS and NeTEx standards.

Task

Research and determine the feasibility of estimating CO2 emissions of GTFS and NeTEx transport modes. If it seems feasible, create a follow-up task to track the implementation.

Related resources

• Stemming from OpenTripPlanner modes adapter and ferry calculation #47
• Based on comment List of transit modes or travel options supported by OTP? opentripplanner/OpenTripPlanner#3076 (comment)