Through the Transport Analysis tab->Route Analysis group->Environment Settings function, you can uniformly manage 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 display styles for different graphical 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, refer to the Styles page.
• Traffic Rules Settings: Used to configure traffic rules for network arcs. You can set traffic attributes for road segments, including: two-way traffic, forbid to pass, forward value, or backward value. For details, refer to the Traffic Rules Settings page.
• Turn Table Settings: Used to manage turn tables required for network analysis, including Create Turn Table and Set Turn Table.
• Weight Settings: Weight Settings includes 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 network analysis. After setting, the system will only load network data within this area to improve analysis efficiency. For details, 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, refer to the Trace Analysis Network Modeling page.
• Check Loops: Used to check whether there are loops in the network dataset. For details, refer to the Check Loops page.

Network Dataset Information

• Select Dataset: When there are multiple network datasets, select the target network layer in this drop-down list to apply environment settings.
• Dataset Information: Displays the basic information of the dataset when performing 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 drop-down box as the forward/backward weight field for network dataset arcs. You can choose any field from the current network layer as the weight field.

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

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

    • Node ID Field: Select a field from the right drop-down box as a unique identifier for each node in the network dataset. You can choose a field from the point dataset in the network dataset as the marking field. The application defaults to using the SMNODEID field as the node ID field.
    • Edge ID Field: Select a field from the right drop-down box as a unique identifier for each arc in the network dataset. You can choose a field from the line dataset in the network dataset as the marking field. The application defaults to using SMEDGEID as the edge ID field.
    • Start/End Node ID: Select a field from the right drop-down box that identifies the start/end node in the network dataset. You can choose a field from the line dataset in the network dataset as the marking field. The application defaults to using SMTNODE as the start/end node ID.
    • Edge Filter: Set arcs to be filtered out during analysis. During network analysis, only arc objects that satisfy this expression are considered. You can directly input an expression or choose Expression… to use the SQL Expression dialog to define expressions. For how to use SQL Expression, refer to the SQL Expression page.
    • Traffic Rules: Set whether to enable rules during analysis. You can configure traffic rules settings according to actual needs. The application disables this by default. For how to set traffic rules, refer to the Setting Traffic Rules page.
    • Turn Table: Set whether to enable during analysis. You can configure turn table settings according to actual needs. The application disables this by default. For how to create and set turn tables, refer to the Turn Table page.
  • Result Settings:
    • Result Datasource: The data source where network analyst results are saved by default. Subsequent network analyst results will be saved in this data source by default. It defaults to the data source where the current network dataset is located.
    • Edge Info Field: A field that provides arc information, such as the road name field. It can be used to generate route guides.
    • Node Info Field: A field that provides node information, such as the bus stop name field. 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 flow direction of arcs.