Outputs#

The Van model creates a new folder for each run to store all outputs inside, this folder follows the name convention of “LGV Model Outputs - {date} {time}” (e.g. “LGV Model Outputs - 2021-08-05 19.15.32”). The Van model outputs are split into three sub-folders “trip ends”, “annual trip matrices” and “time period matrices”, the outputs for each are discussed in the next sections.

Trip Ends#

The trip ends folder contains six CSVs, which each contain the trip end values for each of the following model segments:

  • Service

  • Delivery Grocery

  • Delivery Parcel Bush

  • Delivery Parcel Stem

  • Commute Drivers

  • Commute Skilled Trades

The output files are named after the segments e.g. service_trip_ends.csv and they’re all saved in the CSV format with column headers on the first row and three columns. All outputs are given as production and attraction trip ends, except delivery grocery and delivery parcel bush which are origin and destinations.

Trip ends outputs CSV columns.#

Column Name

Data Type

Description

Zone

Integer

The model zone number

Productions (or Origins)

Real

The number of production (or origin) trip ends for this zone

Attractions (or Destinations)

Real

The number of attraction (or destination) trip ends for this zone

Annual Trip Matrices#

The annual trip matrices folder contains the following three or four files for each of the model segments:

  • Annual trip matrix in productions / attractions format (if the model segment is in that format)

  • Annual trip matrix in origin / destination format

  • Excel log file

  • PDF trip distributions graph

The following sections discuss each of the above files in more detail.

Annual Trip Matrix#

The annual trip matrix files (both OD and PA) are provided as CSVs in the square matrix format i.e. the first row and column contain all the zone numbers and the remaining cells contain the values. All van model segments have an OD matrix and all, except delivery grocery and delivery parcel bush, have a PA matrix too. The naming conventions for the two matrices are as follows:

  • PA: {segment_name}-trip_matrix-PA.csv

  • OD: {segment_name}-trip_matrix-OD.csv

Excel Log File#

The Excel log spreadsheet that is created contains various statistics and results from the van model process. Aggregated statistics are used by translating the matrix to a higher level summary zone system using the summary_zone_translation input. The spreadsheet is named {segment_name}-GM_log.xlsx and contains the following worksheets:

  • Summary: This sheet contains high-level statistics of the sector aggregated and original matrices. Including mean, min, max, standard deviation, 5%, 25%, 50%, 75% and 95% percentiles, sum, number of zeros and almost zeros and number of NaNs.

  • Trips Ends: This sheet contains the sector aggregated trip ends of the resultant matrix.

  • Matrix: Contains the sector aggregated matrix.

  • Calibration Results: This sheet lists the calibration parameters used for the final run of the gravity model and the \(R^2\) values when the matrix is compared against the trip distributions.

  • Furnessing Results: This sheet provides the results of the furnessing process on the final run of the gravity model.

  • Trip Distribution: This sheet is a table containing the observed trip distribution compared to the matrix distribution.

  • Vehicle Kilometres: This sheet is a table of the total trips and vehicle kilometres in the annual OD matrix.

  • Vehicle Kilometres (PA): This sheet contains the same information as above but for the PA matrix, if this model segment is PA.

Calibration Log#

Contains the results of each gravity model loop for each TLD category. The file are named gravity_model_{segment_name}-calibration_log.csv. Result contained are, attempt ID, loop number, runtime and resultant cost parameters and convergence for each TLD category

Trip Distributions Graph#

The PDF contains a graph of the observed trip distributions compared to the output annual trip matrix distributions. The file is named {segment_name}-distribution_{category}.pdf and contains the distributions plotted for the observed data and the calibration sub-subset of the matrix for the TLD category. All the data used to produce these graphs is given in the Trip Distribution sheet of the Excel Log File.

Time Period Matrices#

The time period matrices folder contains a CSV with all the input time period factors listed and sub-folders for each time period. Each time period sub-folder contains square matrix CSVs for each of the six model segments, all matrices have the zones in the first column and row and have the time period name as a prefix e.g. AM_service-trip_matrix.csv.