Block transfer example

Block transfer, also called in-seat transfer, is available when a set of trips meets the following conditions:

  1. The trips are consecutive.
  2. The same vehicle operates both trips.
  3. The trips are provisioned with the same block_id value in the trips.txt file in the transit feed.

Prerequisites

For Google Maps to recognize that block transfers between trips are possible, the following prerequisites must be met:

  1. The trips must use the same block_id value in trips.txt. This indicates that the trips use the same vehicle.
  2. The trips must operate on the same days, or on consecutive days if a trip crosses midnight.
  3. The trips must be consecutive and not overlap.
  4. The last stop of the arriving trip and the first stop of the departing trip must either be the same (recommended) or physically close.

Use block_id to enable block transfers

Block transfers can be made between consecutive trips on different routes or on the same route if the route is a loop line. Use the block_id field to specify which trips are in one block and where in-seat transfers are an available option.

Example 1: Block transfers for scheduled trips

In this example, consider the following values in each file:

trips.txt

route_id trip_id block_id
RouteA RouteATrip1 Block1
RouteB RouteBTrip1 Block1

stop_times.txt

trip_id arrival_time departure_time stop_id stop_sequence
RouteATrip1 12:00:00 12:01:00 A 1
RouteATrip1 12:05:00 12:06:00 B 2
RouteATrip1 12:15:00 C 3
RouteBTrip1 12:18:00 C 1
RouteBTrip1 12:22:00 12:23:00 D 2
RouteBTrip1 12:30:00 E 3

In this example:

  • A user who searches for a route from stop A to stop E is directed to embark at stop A at 12:00 on Route A and to stay on the vehicle when it reaches stop C after the end of RouteATrip1. This is because the same vehicle services RouteBTrip1 for Route B.
  • Passengers on RouteATrip1 who want to continue on to a stop on RouteBTrip1 can stay on the vehicle for this transfer.
  • Passengers of other trips on other vehicles along these same routes don't have this option because they use different vehicles for each trip.

Example 2: Block transfers for frequency-based trips with exact times

Block transfers are supported only for frequency-based trips that meet one of the following conditions, in addition to the requirements listed in the Prerequisites section:

  • If the trip is a loop, it must start and end at the same stop.
  • In frequencies.txt, the value of the exact_times field must be 1.

The following example describes how to set the values for the second condition:

trips.txt

route_id trip_id block_id
route1 route1_trip1 block_2
route2 route2_trip1 block_2

stop_times.txt

trip_id arrival_time departure_time stop_id stop_sequence
route1_trip1 08:00:00 08:04:00 stop1 1
route1_trip1 08:10:00 08:14:00 stop2 2
route1_trip1 08:20:00 stop3 3
route2_trip1 08:24:00 stop3 1
route2_trip1 08:30:00 08:34:00 stop4 2
route2_trip1 08:40:00 08:44:00 stop5 3

frequencies.txt

trip_id start_time end_time headway_secs exact_times
route1_trip1 08:00:00 08:20:00 600 1
route2_trip1 08:24:00 08:44:00 600 1

In this example:

  • A user who searches for a route from stop1 to stop5 is directed to embark at stop1 at 08:00 on route1. The user then stays on the vehicle when it reaches stop3 after the end of route1_trip1. This is because the same vehicle services route2_trip1 for route2.
  • Passengers on route1_trip1 who want to continue on to a stop on route2_trip1 can stay on the vehicle for this transfer.
  • Passengers of other trips on other vehicles along these same routes don't have this option because they use different vehicles for each trip.
  • Take route1_trip1 for example. The value of headway_secs is half the interval between start_time and end_time. In this case, it means there are two trips. To learn more about the usage of headway_secs, refer to the GTFS Schedule Reference on gtfs.org.

Block transfer in a loop line

In a loop line, the first stop and the last stop of a trip are the same and have the same stop_id. This is required for both schedule-based and frequency-based trips.

Provided that consecutive loop trips have the same block_id, block or in-seat transfer is enabled, which lets passengers of the first trip remain on the vehicle when it continues on the next loop.

Valid blocks in GTFS feeds

For block transfer to be possible, you must properly define one or more blocks in the feed. To pass validation, trips that belong to the same block can't overlap and must have the same route_type (subway, rail, bus, and so forth). Trips can belong to the same block even if they're on different days. If any blocks are defined in a static feed, they show in the Validation Report, on the Overview tab.