Parking Results and Outputs

The parking module produces several categories of output data, written to the simulation’s output databases. These outputs enable post-simulation analysis of parking demand, supply utilization, costs, and choice behavior.

The figure below shows how simulation events flow through per-thread buffers into the output databases, and how zone-level costs computed at startup feed into upstream demand models.

Parking Records

Every individual parking event—whether for a personal vehicle or a TNC fleet vehicle—is recorded in the Parking_Records table of the Demand database. Each record captures:

Field	Description
Parking_ID	The unique identifier of the parking facility used. A value of -1 indicates the vehicle failed to find parking.
Location_ID	The activity location ID associated with the parking event
Link_ID	The network link where the vehicle parked
Vehicle	Reference to the vehicle record
Person	Reference to the person record (null for TNC & Freight vehicles without a traveler)
Time_In	Simulation time (seconds) when the vehicle entered the parking facility
Time_Out	Simulation time (seconds) when the vehicle exited the parking facility
Is_TNC_Vehicle	Boolean flag distinguishing fleet vehicles from personal vehicles
Cost	The parking cost incurred, computed from the facility’s pricing rules
Choice_Id	Links back to the corresponding Parking_Choice_Records entry, if applicable
Escooter_Borrowed	Whether the person borrowed an e-scooter from the parking facility

Records are buffered per simulation thread and periodically flushed to the database to minimize I/O overhead. The double-buffering pattern (active buffer and write buffer) ensures thread safety during concurrent simulation and writing.

Parking Choice Records

When parking choice logging is enabled in the scenario settings, the Parking_Choice_Records table captures detailed information about every pre-trip parking choice decision. These records are useful for model validation and recalibration.

Each record includes:

Field	Description
Choice_ID	Unique identifier for the choice event
Person	Reference to the person making the choice
choice_event_time	Simulation time of the choice event
type	The parking type of this alternative (on-street or garage)
chosen	Whether this alternative was the selected option
parking_fee	Estimated parking cost for this alternative
distance_to_G	Distance to this garage alternative (for garage options)
Garage_ID	Parking facility ID (for garage options)
Reserved	Whether the chosen garage was successfully reserved
destination	Activity location ID of the trip destination
NumGarageChoices	Number of garage alternatives in the choice set
ChoiceExist	Whether any garage alternatives existed (even if filtered by occupancy)
CanUseEscooter	Whether the person is eligible to use an e-scooter for parking access
is_depart_pk	Peak departure indicator
act_dur_hr	Activity duration in hours
female	Gender indicator
hhsize	Household size
ln_hhinc	Log of household income
urgent	Mandatory activity indicator
age_above_60	Age indicator
ln_dest_empdens	Log of destination employment density
ln_dest_popdens	Log of destination population density

Parking Occupancy Time Series

The parking result logger periodically writes parking occupancy snapshots to the Parking_Occupancy table in the Result database. The logging interval is controlled by a configurable scenario parameter.

At each logging interval, for every parking facility in the network, the logger records:

Field	Description
Parking_ID	The parking facility identifier
Start_Time	Start of the logging interval
End_Time	End of the logging interval (current simulation time)
Occupancy	Ratio of currently parked vehicles to total spaces

This time-series data enables analysis of how parking demand varies throughout the day, identification of peak occupancy periods, and assessment of whether parking supply is adequate in different parts of the network.

Zone-Level Parking Cost

During network initialization, average parking costs are computed for each traffic analysis zone and stored for use in other models (e.g., mode choice, destination choice). Two averages are maintained:

• Short-duration cost: Weighted average cost for a 1-hour stay across all parking facilities in the zone.

• Routine activity cost: Weighted average cost for an 8-hour stay, representative of a workday parking cost.

These zone-level costs provide aggregate parking price signals to upstream demand models without requiring facility-level detail.