Transit directions return additional information that is not relevant for other modes of transportation. These additional properties are exposed through the transit_details object, returned as a field of an element in the steps[] array. From the TransitDetails object you can access additional information about the transit stop, transit line and transit agency

interface TransitDetails {
    arrival_stop: TransitStop;
    arrival_time: Time;
    departure_stop: TransitStop;
    departure_time: Time;
    headsign: string;
    headway: number;
    line: TransitLine;
    num_stops: number;
}

Properties

arrival_stop: TransitStop

contains information about the stop for this part of the trip.

arrival_time: Time

contain the arrival time for this leg of the journey.

departure_stop: TransitStop

contains information about the station for this part of the trip.

departure_time: Time

contain the departure time for this leg of the journey.

headsign: string

specifies the direction in which to travel on this line, as it is marked on the vehicle or at the departure stop. This will often be the terminus station.

headway: number

specifies the expected number of seconds between departures from the same stop at this time. For example, with a headway value of 600, you would expect a ten minute wait if you should miss your bus.

contains information about the transit line used in this step.

num_stops: number

contains the number of stops in this step, counting the arrival stop, but not the departure stop. For example, if your directions involve leaving from Stop A, passing through stops B and C, and arriving at stop D, num_stops will return 3.