Via theTransport Analysis tab -> Route Analysis group -> Environment Settings function, you can uniformly manage the various global parameters of network analysis. However, parameters within the panel can only be set when a network dataset is loaded in the current map.

Toolbar

The toolbar of the Environment Settings panel organizes the functions of the network analysis environment.

• Styles: You can individually set the display styles for different graphic elements that appear in network analysis as needed, including points (such as stations, barrier points, etc.), lines (such as result paths), areas (such as service areas), and text labels (such as prompts). For details, please refer to the Styles page.
• Traffic Rules Settings: Used to configure the traffic rules of network arcs. You can set passing attributes for road segments, including: bidirectional passing, forbidden to pass, forward value, or backward value. For details, please refer to the Traffic Rules Settings page.
• Turn Table Settings: Used to manage the turn tables required for network analysis, including Create Turn Table and Set Turn Table.
• Weight Settings: Weight settings include updating edge weight and node weight. Update Edge Weight is used to set the forward/backward weight of arcs and whether the arc is a barrier edge. Update Node Weight is used to set the turning weight at nodes and whether the node is a barrier point.
• Analysis Bounds Settings: Used to set the area for performing network analysis. After setting, the system will only load network data within this area to improve analysis efficiency. For details, please refer to the Analysis Area Settings page.
• Trace Analysis Network Modeling: Used to set parameters for trace analysis, including the node ID field and edge ID field of the facility network, whether to create flow direction, whether to create levels, etc. For details, please refer to the Trace Analysis Network Modeling page.
• Check Loops: Used to check whether there are loops in the network dataset. For details, please refer to the Check Loops page.

Network Dataset Information

• Select Dataset: When multiple network datasets exist, select the target network layer from this dropdown list to apply environment settings.
• Dataset Information: Displays the basic information of the dataset during network analysis.
  • Network Analysis Basic Parameters:
    • Network Dataset: Displays the name of the network dataset currently undergoing environment settings, which cannot be edited.
    • Forward/Backward Weight Field: Select a field from the right dropdown as the forward/backward weight field for network dataset arcs. You can choose any field of the current network layer as the weight field.

      The weight field represents the cost value from one point to another in the network nodes. In practical applications, we can use fields such as distance, time, or cost as the weight field. For example, to calculate the path from point A to point B, you can use the time field as the weight field and then use the path analysis function in network analysis to compute the optimal path analysis between point A and point B. Forward weight refers to the cost from the start of the arc to the end, while backward weight refers to the cost from the end of the arc to the start. These two fields can be set the same (e.g., when setting length as the weight field) or different (e.g., when setting time as the weight field, because the time taken to travel from the start to the end of an arc and from the end to the start may differ in the same time period).

      The weight field supports direct input of expressions, or you can select "Expression..." to use the "SQL Expression" dialog to define the expression. For how to use SQL Expression, please refer to the SQL Expression page.

    • Node ID Field: Select a field from the right dropdown that uniquely identifies each node in the network dataset. You can choose a marking field from the point dataset in the network dataset. The application defaults to using the SMNODEID field as the node ID field.
    • Edge ID Field: Select a field from the right dropdown that uniquely identifies each arc in the network dataset. You can choose a marking field from the line dataset in the network dataset. The application defaults to using SMEDGEID as the edge ID field.
    • Start/End Node ID: Select a field from the right dropdown that identifies the start/end node in the network dataset. You can choose a marking field from the line dataset in the network dataset. The application defaults to using SMTNODE as the start/end node ID.
    • Edge Filter: Set the arcs to be filtered out during analysis. Only arc objects that satisfy this expression will be considered during network analysis. You can directly input the expression or select Expression... to use the SQL Expression dialog to define the expression. For how to use SQL Expression, please refer to the SQL Expression page.
    • Traffic Rules: Set whether to enable rules during analysis, and configure traffic rules as needed. The application defaults to disabled. For how to set traffic rules, please refer to the Set Traffic Rules page.
    • Turn Table: Set whether to enable during analysis, and configure turn table settings as needed. The application defaults to disabled. For how to create and set the turn table, please refer to the Turn Table page.
  • Result Settings:
    • Result Datasource: The datasource where network analysis results are saved by default. Subsequent network analysis results will be saved in this datasource by default. It defaults to the datasource where the current network dataset is located.
    • Edge Info Field: A field that provides arc information, such as the name field of a road, etc. It can be used to generate route guides.
    • Node Info Field: A field that provides node information, such as the name field of a bus stop, etc. It can be used to generate route guides.
  • Trace Analysis:
    • Flow Direction Field: A precondition for trace analysis, you need to specify a flow direction field to indicate the direction of arc flow.