tnc request table structure#
The TNC_Request table stores records for all requests recevied by any shared mobility operator in POLARIS. A variety of information is recorded to understand demand for the different shared mobility services, and the outcome details when trying to serve the request is also logged.
The data in this table is purely an output of POLARIS and is not read back in by subsequent iterations.
Field |
Type |
NULL allowed |
Default Value |
Foreign key |
Description |
|---|---|---|---|---|---|
TNC_request_id* |
INTEGER |
NO |
Unique identifier for requests that are made in the simulation. |
||
request_time |
REAL |
YES |
0 |
Time at which the request was made (units: seconds) |
|
assignment_time |
REAL |
YES |
0 |
Time at which the request is assigned to a vehicle or 0 if not assigned. (units: seconds) |
|
pickup_time |
REAL |
YES |
0 |
Time at which the request was picked up by the vehicle or 0 if not assigned. (units: seconds) |
|
dropoff_time |
REAL |
YES |
0 |
Time at which the request was dropped off by the vehicle or 0 if not assigned or was not dropped off before simulation ended. (units: seconds) |
|
access_walk_duration |
REAL |
YES |
0.0 |
Time needed for request to walk to vehicle from origin before pickup, if needed. (units: seconds) |
|
egress_walk_duration |
REAL |
YES |
0.0 |
Time needed for request to walk to destination from vehicle after dropoff, if needed. (units: seconds) |
|
origin_location |
INTEGER |
NO |
0 |
Location of the request origin. Can be 0 if origin is not near any location and is only tagged by a link. (foreign key to the Location table) |
|
destination_location |
INTEGER |
NO |
0 |
Location of request destination. Can be 0 if destination is not near any location and is only tagged by a link. (foreign key to the Location table) |
|
origin_link |
INTEGER |
NO |
0 |
Link of the request origin. Cannot be NULL/0. (foreign key to the Link table) |
|
destination_link |
INTEGER |
NO |
0 |
Link of the request destination. Cannot be NULL/0. (foreign key to the Link table) |
|
adjusted_origin_location |
INTEGER |
NO |
0 |
Certain assignment strategies may alert requests to walk/move to a nearby location from the origin and the new origin Location ID is stored in this column. |
|
adjusted_destination_location |
INTEGER |
NO |
0 |
Certain assignment strategies may alert requests to walk/move from a nearby location to the destination and the new destination Location ID is stored in this column. |
|
adjusted_origin_link |
INTEGER |
NO |
0 |
Certain assignment strategies may alert requests to walk/move to a nearby link from the origin and the new origin Link ID is stored in this column. |
|
adjusted_destination_link |
INTEGER |
NO |
0 |
Certain assignment strategies may alert requests to walk/move from a nearby link to the destination and the new destination Link ID is stored in this column. |
|
service_mode |
INTEGER |
NO |
0 |
The shared mobility mode requested that is consistent with the entries in the Mode table. Options now include TNC, On-Demand Delivery, or Relocation for E-Scooters. |
|
origin_zone |
INTEGER |
NO |
0 |
The origin Zone of the request (foreign key to the Zone table) |
|
destination_zone |
INTEGER |
NO |
0 |
The destination Zone of the request (foreign key to the Zone table) |
|
pooled_service |
INTEGER |
NO |
0 |
boolean flag - did the request allow pooling? (Not a guarantee that the ride was actually pooled) |
|
party_size |
INTEGER |
NO |
0 |
Number of travelers/objects bundled within this request |
|
estimated_od_travel_time |
REAL |
YES |
0 |
Estimated travel time obtained from the skim (units: seconds) |
|
person |
INTEGER |
YES |
Person(person) |
Person ID that requested the trip, if it is a TNC mode request. NULL if it is an on-demand delivery or e-scooter request. (foreign key to the Person table) |
|
assigned_vehicle |
INTEGER |
YES |
Vehicle(assigned_vehicle) |
Shared mobility vehicle assigned to serve the request. Unassigned request if NULL. (foreign key to the Vehicle table) |
|
number_of_attempts |
INTEGER |
NO |
0 |
Number of attempts made in finding a candidate vehicle for assigning to the request. Each attempt is made every 30 seconds until the TNC_MAX_ASSIGNMENT_TIME threshold is hit. |
|
fare |
REAL |
YES |
0.0 |
Fare collected in serving the request (units: $USD) |
|
distance |
REAL |
YES |
0.0 |
Distance traveled in serving the request (units: miles) |
|
discount |
REAL |
YES |
0.0 |
Discount provided when trip is assigned to a vehicle by operator (units: $USD) |
|
service_type |
INTEGER |
YES |
0 |
Service type requested based on the available options defined in @@ TNC_Service_Types @@ |
|
seating_type |
INTEGER |
YES |
0 |
Number of minimum seats requested for the vehicle, regardless of how many seats will be occupied by request. |
(* - Primary key)
The SQL statement for table and index creation is below.
CREATE TABLE "TNC_Request" (
"TNC_request_id" INTEGER NOT NULL PRIMARY KEY,
"request_time" REAL NULL DEFAULT 0,
"assignment_time" REAL NULL DEFAULT 0,
"pickup_time" REAL NULL DEFAULT 0,
"dropoff_time" REAL NULL DEFAULT 0,
"access_walk_duration" REAL NULL DEFAULT 0.0,
"egress_walk_duration" REAL NULL DEFAULT 0.0,
"origin_location" INTEGER NOT NULL DEFAULT 0,
"destination_location" INTEGER NOT NULL DEFAULT 0,
"origin_link" INTEGER NOT NULL DEFAULT 0,
"destination_link" INTEGER NOT NULL DEFAULT 0,
"adjusted_origin_location" INTEGER NOT NULL DEFAULT 0,
"adjusted_destination_location" INTEGER NOT NULL DEFAULT 0,
"adjusted_origin_link" INTEGER NOT NULL DEFAULT 0,
"adjusted_destination_link" INTEGER NOT NULL DEFAULT 0,
"service_mode" INTEGER NOT NULL DEFAULT 0,
"origin_zone" INTEGER NOT NULL DEFAULT 0,
"destination_zone" INTEGER NOT NULL DEFAULT 0,
"pooled_service" INTEGER NOT NULL DEFAULT 0,
"party_size" INTEGER NOT NULL DEFAULT 0,
"estimated_od_travel_time" REAL NULL DEFAULT 0,
"person" INTEGER NULL,
"assigned_vehicle" INTEGER NULL,
"number_of_attempts" INTEGER NOT NULL DEFAULT 0,
"fare" REAL NULL DEFAULT 0.0,
"distance" REAL NULL DEFAULT 0.0,
"discount" REAL NULL DEFAULT 0.0,
"service_type" INTEGER NULL DEFAULT 0,
"seating_type" INTEGER NULL DEFAULT 0,
CONSTRAINT "person_fk"
FOREIGN KEY ("person")
REFERENCES "Person" ("person")
DEFERRABLE INITIALLY DEFERRED,
CONSTRAINT "assigned_vehicle_fk"
FOREIGN KEY ("assigned_vehicle")
REFERENCES "Vehicle" ("vehicle_id")
DEFERRABLE INITIALLY DEFERRED);