Consider incorporating TNCs/Ride-hail services

[sdrewc]

Given that TNCs are typically considered to be part of a "mobility-as-a-service" package, and currently the most impactful, they seem like a natural extension to this data standard. The key changes would be to add 'automobile' as a vehicle_type, and to create an out-of-service API analogous to the trip API. Or even more simply, a field for 'in-service' or 'out-of-service'.

[migurski]

This is a great idea, 👍 to vehicle_type=automobile. One wrinkle would be the device ID: it doesn’t identify any person for a scooter, but TNC vehicles are privately owned cars with drivers who have an expectation of privacy. The device_id should be optional in this case.

[hunterowens]

I'm going to try and assemble a draft PR for this today.

One question I am struggling with - how to represent shared trips, ie, when the trip has more than one passenger.

[migurski]

I spoke with Stephanie Dock from DDOT about this on Wednesday and she helped me see that shared trips represent a big change to the MDS trip data model. Maybe MDS should set TNCs aside for the moment to ensure that it’s successful for single-occupant micromobility devices?

[hunterowens]

Yeah. My thought would be to have each mode have its own directory in provider, as such, in provider.

├── auth.md
├── micromobility
│   ├── README.md
│   ├── status_changes.json
│   └── trips.json
└── tnc
    └── README.md

We could then use the common datatypes from JSONSchema in generate_schema to share datatypes, enums, etc.

[chursaner]

I like that. In the future, we could also have directories for goods_delivery, air... I'd suggest using simply "vehicle" above "tnc" to encompass taxis, limos, tncs, as well as private vehicles if there were to be an incentive or reason for individuals to share data via MDS. I think we need to be careful not to create a sense that shared mobility has all these requirements that you are immune to if you own your vehicle-- small differences in language can make a big difference in how people weigh the decision of owning a car.

├── auth.md
├── micromobility
│ ├ README.md
│ ├ status_changes.json
│ ├ trips.json
├── vehicle
│ ├ README.md
│ ├ trips.json

[chursaner]

@hunterowens Drafted vehicle trips on my fork here https://github.com/chursaner/mobility-data-specification/blob/0.2.x/provider/vehicle/trips.json . I can add it as a pull request once you reorganize the directory!

A few differences from micromobility-

1. Vehicle type is a combination of vehicle type and propulsion type - includes things like automobile, taxi, carshare, electric; allows multiple values
2. New field for occupancy that has values "single", "shared" and "high". The spec defines high as >4 passengers- this is something that individual agencies will decide on
3. Allow vehicle ID to be null (ie optional)

[chursaner]

Would the Accuracy field still be applicable? Also need to switch time to be in minutes rather than seconds, though I wonder if that's something we could calculate on the back end using start and end time rather than ask for the information from the provider

[sdrewc]

@migurski "TNC vehicles are privately owned cars with drivers who have an expectation of privacy. The device_id should be optional in this case."
The vehicles are privately owned, but they're providing a commercial service. Taxi medallions and vehicles may also be privately owned, but don't have a similar presumption, and in fact often report both the vehicle and driver. Definitely IDs should be anonymized, but there is analytical value in being able to link trips since research shows there is almost as much deadhead VMT as in-service VMT.

[sdrewc]

@chursaner "I'd suggest using simply "vehicle" above "tnc" to encompass taxis, limos, tncs, as well as private vehicles if there were to be an incentive or reason for individuals to share data via MDS."
I don't think it makes sense to include private vehicles in the same category as for-hire vehicles for a few reasons:

1. for-hire vehicles are providing a service and necessarily have different operating profile. Mixing these with regular cars would confuse any potential analysis.
2. private vehicles aren't a mobility service, as I understand the term
3. individuals are unlikely to be contributing their data. When a mobility service provider reports its data, it's descriptive of the "universe" of activity, while individuals would be a sample with unknown bias.
4. I think that soliciting data from private individuals not engaged in a commercial activity is potentially fraught.

[sdrewc]

@chursaner thanks for adding occupancy! Why not simply ask for the number of passengers instead of a categorical?