Vehicle Locations Schema

Question 1

What is the primary key for the vehicle_locations table?

Answer 1

location_ping_id

Question 2

What is the description of the vehicle_locations table?

Answer 2

Timestamped vehicle locations and speeds

Question 3

What is the table type of vehicle_locations?

Answer 3

Event

Question 4

What does the location_ping_id field represent?

Answer 4

Identifies the recorded vehicle location event

Question 5

What are the constraints on the location_ping_id field?

Answer 5

Required: true, Unique: true

Question 6

What does the service_date field represent?

Answer 6

Service date. References GTFS

Question 7

What does the event_timestamp field represent?

Answer 7

Recorded event timestamp

Question 8

Is the event_timestamp field required?

Answer 8

Yes

Question 9

What does the trip_id_performed field represent?

Answer 9

Identifies the trip performed. If trips_performed table is used, this must be populated in order to link to it

Question 10

What does the trip_id_scheduled field represent?

Answer 10

Identifies the scheduled trip

Question 11

What does the trip_stop_sequence field represent?

Answer 11

The actual order of stops visited within a performed trip

Question 12

What is the minimum value for trip_stop_sequence?

Answer 12

1

Question 13

What does the scheduled_stop_sequence field represent?

Answer 13

Scheduled order of stops for a particular trip. References GTFS

Question 14

What is the minimum value for scheduled_stop_sequence?

Answer 14

0

Question 15

What does the vehicle_id field represent?

Answer 15

Identifies a vehicle

Question 16

Is the vehicle_id field required?

Answer 16

Yes

Question 17

What does the device_id field represent?

Answer 17

Identifies the device that recorded the vehicle location

Question 18

What does the pattern_id field represent?

Answer 18

Identifies the unique stop-path for a trip, may be distinct from GTFS shapes.shape_id

Question 19

What does the stop_id field represent?

Answer 19

Identifies the stop the vehicle is approaching or serving currently. References GTFS

Question 20

What does the current_status field represent?

Answer 20

Indicates the status of the vehicle in reference to a stop. References GTFS-Realtime

Question 21

What are the possible values for current_status?

Answer 21

Incoming at, Stopped at, In transit to

Question 22

What does the latitude field represent?

Answer 22

Degrees North, in the WGS-84 coordinate system. References GTFS-Realtime

Question 23

What are the constraints on the latitude field?

Answer 23

Minimum: -90, Maximum: 90

Question 24

What does the longitude field represent?

Answer 24

Degrees East, in the WGS-84 coordinate system. References GTFS-Realtime

Question 25

What are the constraints on the longitude field?

Answer 25

Minimum: -180, Maximum: 180

Question 26

What does the gps_quality field represent?

Answer 26

Indicates the quality of data and communication provided by the GPS

Question 27

What are the possible values for gps_quality?

Answer 27

Excellent, Good, Poor

Question 28

What does the heading field represent?

Answer 28

Heading, in degrees, clockwise from true north

Question 29

What are the constraints on the heading field?

Answer 29

Minimum: 0, Maximum: 360

Question 30

What does the speed field represent?

Answer 30

Momentary speed measured by the vehicle, in meters per second

Question 31

What is the minimum value for speed?

Answer 31

0

Question 32

What does the odometer field represent?

Answer 32

Odometer value, in meters

Question 33

What is the minimum value for odometer?

Answer 33

0

Question 34

What does the schedule_deviation field represent?

Answer 34

Indicates schedule adherence in seconds. A negative value represents an early vehicle

Question 35

What does the headway_deviation field represent?

Answer 35

Indicates headway adherence in seconds. A negative value represents a shorter than scheduled headway

Question 36

What does the trip_type field represent?

Answer 36

Indicates status of travel with regard to service

Question 37

What are some possible values for trip_type?

Answer 37

In service, Deadhead, Layover, Pullout, Pullin

Question 38

What does the schedule_relationship field represent?

Answer 38

Indicates the status of the stop

Question 39

What are the possible values for schedule_relationship?

Answer 39

Scheduled, Skipped, Added, Missing

Question 40

What foreign references does the vehicle_locations table have?

Answer 40

service_date+trip_id_performed → trips_performed, service_date+trip_id_performed+stop_sequence → stop_times, vehicle_id → vehicles, device_id → devices