Trans CAD Basic Network Analysis 9182020 1 Basic

Trans. CAD Basic Network Analysis 9/18/2020 1

Basic Network Analysis Trans. CAD includes a broad and diverse set of analytic and graphical display tools for working with transportation networks. There tools include algorithms for two very common problems – the traveling salesman problem and the network partitioning problem – which have numerous practical applications in both the public and private sector. 9/18/2020 2

Basic Network Analysis Many transportation problems involve determining the best (or least cost) way to make a series of deliveries or stops. Examples of this include: A supplier scheduling customer deliveries A school department scheduling the stops for a school bus A salesman planning a trip to a number of customer sites All these problems have the same basic structure – to minimize the cost of visiting a group of stops with no requirements about order. 9/18/2020 3

To Solve a Traveling Salesman Problem(Travel_s. map) 9/18/2020 4

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Solving a Network Partitioning Problem Trans. CAD partitions a network by computing the network cost between each service location and all the links and nodes in the network. Each link and node is labeled with the ID of the “closest” service location, and the cost of the trip. To solve a network partitioning problem, you must do three things: Create a network Select the service locations Use the network partitioning routine 9/18/2020 6

To Partition a Network (Net_part. map) 9/18/2020 7

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Creating Network Bands A network band encloses an area in which all links or nodes on a network are within a certain impedance, or value limit, of an origin. Creating network bands is useful, for example, for finding the distance from one or more origins along links in a network that can be covered within a certain amount of time, or finding the number of locations within a certain distance of one or more origins. 9/18/2020 9

Creating Network Bands Trans. CAD creates bands by creating points along the network at which a certain value that your set is reached, and then joining those points to draw the border of each band. To create network bands, you must do three things: Create a network Select the origin locations from the node layer Use the network bands routine The origins are stored in a selection set on the node layer 9/18/2020 10

To Create Network Bands 9/18/2020 11

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Create an Intersection Diagram Should be AB_Flow & BA_Flow 9/18/2020 13