Addition of vehicles.txt to GTFS static

### Describe the problem

Real time prediction tools could use additional information to describe what type of vehicle is approaching and its capacity and accessibility features.

### Use cases

Real-time data usually includes the vehicle number which could be used to look up more details about the vehicle then it would be practical to include with the real-time data feed. Capacity would be used to indicate how busy a vehicle is if the real-time passenger load is provided. The vehicle type would be useful to indicate when a rail vehicle has been replaced by a bus.

This could also be used for reporting fleet information in a standard format for analyses by other levels of government and the public.

### Proposed solution

A new vehicles.txt file in the GTFS static file to describe the capacity, accessibility and features of individual vehicles or vehicle ranges. It would apply to buses, LRT, subway cars, rail cars and even ferries.

Fields could include:

- Id: Corresponds to the id in the VehicleDescriptor in the real-time data. Required and unique
- High_Id: If the vehicle description covers a range of identical vehicles the Id is the lower end of the range and High_Id is the high end. Only the numbers can increment. Any non-numeric characters must not change. Leading zero in the Id are maintained.
- Label: Corresponds to the label in the VehicleDescriptor in the real-time data.
- High_Label: If the vehicle description covers a range of identical vehicles the Label is the lower end of the range and High_Label is the high end. Only the numbers can increment. Any non-numeric characters must not change. Leading zero in the Label are maintained. The range must be the same size as the range covered by the Id and High_Id.
- Vehicle_Type: Could match the values of [Route_Type](https://gtfs.org/schedule/reference/#routestxt)
- Manufacturer
- Model
- Year: Year ordered
- Length_Feet
- Length_Meters
- Articulations
- Number_of_Levels
- Seated_Capacity
- Standing_Capacity
- Wheelchair_Capacity
- Interior_Bicycle_Capacity
- Exterior_Bicycle_Capacity
- Bicycle_Notes: A text description of how bicycles are stored and any limitations that may apply, such as times when they are disallowed. Translatable
- Luggage: Has space for luggage that is larger than carry-on luggage. 1- Luggage rank in the passenger area; 2- Luggage storage under or behind the passenger area (such as a coach bus).
- Luggage_Notes: A text description of how luggage is stored and any limitations that may apply. Translatable
- Restrooms: Number of restrooms in the vehicle
- AirConditioned: 1- Has functioning Air Conditioning
- AC_Plugs: Number of AC power plug that follow the local standard available to passengers
- USB_Plugs: Number of USB type-A ports available for device charging
- WiFi: 1- Internet access through WiFi with no login required; 2- Internet access with free login required; 3- Internet Access with payment or paid membership
- WiFi_Notes: Description of how the access the Internet through WiFi and any limitation it has. Translatable
- Number_of_Doors: If the vehicle has doors on both sides, use the number of doors per side.
- Boarding_Level: 1 - High platform level boarding; 2 - Low platform level boarding; 3- Steps to board; 4- Boarding varies by station
- Boarding_Steps: Number of steps to board
- Accessible_Boarding: If there are steps to board, this shows the vehicle may be accessibly boarder. 0-Not accessible; 1-Level boarding; 2- Ramp can be deployed; 3- Lift can be deployed
- Accessible_Door: Door number at supports accessible boarding, where 1 is the first door in the direction of travel
- Accessibility_Notes: Text information about how to board with a mobility device and any limitations. Translatable
- Next_Stop_Announcement: 1- Audible next stop announcements are made in this vehicle for the vision impaired
- Next_Stop_Display: 1- There are interior displays showing the name of the next stop for the hearing impaired
- Special_Decoration: A brief description of a special wrap or modification of the vehicle either seasonal or long term. Translatable
- Propulsion: 1- Unpowered, moved by another unit; 2- Overhead wire; 3- Third rail electric; 4- Battery electric; 5- Hydrogen; 6- ICE-battery hybrid; 7- Internal combustion engine; 8- Cable pulled; 9- Stream engine!?!?!

### Additional information

_No response_