Base Network

The key steps involved in the base network process in EMME, includes;

1. Imports and Initial Setup - Imports necessary modules and functions and defines the BaseNetwork class.
2. Sets up scenario and Emmebank tools - set up the scenario and imports all the Modeller tools.
3. Building Base Network (build_base_network method) - steps included;
   1. Checks if the current time period is the first time period.
   2. Calls build_base_scenario or copy_base_scenario based on the time period.
   3. Imports transit lanes if the model type is not ‘timetable’.
4. Building Base Scenario (build_base_scenario method) - steps included;
   1. Creates a new scenario in EMME.
   2. Deletes any existing placeholder scenarios.
   3. Imports various network elements (modes, vehicles, centroids, nodes, connectors, links, functions).
   4. Builds and imports extra attributes.
   5. Imports corridor attributes and publishes the network.
5. Copying Base Scenario (copy_base_scenario method) - steps included;
   1. Copies an existing scenario to create a new base network scenario.
6. Import Base Network Elements - imports network elements from the sqlite database including;
   • import_modes: Imports modes from the database.
   • import_vehicles: Imports vehicles from the database.
   • import_centroids: Imports centroids from the database.
   • import_nodes: Imports regular nodes from the database.
   • import_connectors: Imports connectors from the database.
   • import_links: Imports links and link vertices from the database.
   • import_functions: Imports functions from the database.
   • import_corridor_attributes: Imports corridor attributes from the database.
   • import_transit_lanes: Imports transit lanes for the current scenario.
   • create_series_attributes: Creates series attributes for the scenario (for timetable model only).
   • import_base_network_attributes: Imports base network attributes for links and nodes.

Transit Network

The key steps involved in the transit network process in EMME, includes;

1. Building Transit Network - The build_transit_network method constructs the transit network based on the model type (Frequency, Timetable, or Olympics). It handles importing transit lines, setting attributes, and configuring transit time functions.
2. Deleting Transit Network - The delete_transit_network method deletes any existing transit network within the EMME scenario.
3. Importing Lines and Headways - The import_lines_files method imports transit line files into EMME. The import_headways method imports headway data for transit lines.
4. Converting Timetable Times - The convert_timetable_times method adjusts timetable times by subtracting 180 minutes (to artifically reflect a 3am to 3am time window for a timetable model only).
5. Importing Transit Attributes - The import_transit_attributes method imports and sets various transit line and stop attributes from a database.
6. Splitting Transit Times - The split_transit_times method splits transit times into intermediate segments using specified attributes.
7. Setting Transit Time Functions - The set_transit_time_functions method sets up transit time functions based on data from a database.
8. Using Auto Times for Bus Lines - The use_auto_times_for_bus_lines method adjusts bus line times based on auto travel times.
9. Setting Crowded Assignment Values - The set_crowded_assignment_values method imports and sets additional attributes for crowded transit assignments.