UP206A: Introduction to GIS

» The ArcGIS Network Analyst extension allows you to build a network dataset and perform analysis on a network dataset » Used primarily on Transportation Networks » This extension is composed of a number of parts: ˃ a wizard to create a network dataset (in ArcCatalog) ˃ a dockable Network Analyst window (in ArcMap) ˃ a Network Analyst toolbar (in ArcMap) ˃ and a number of geoprocessing tools contained within ArcToolbox

» The Network Analyst toolbar is a combination of menus and buttons for adding and modifying network locations, generating directions, identifying network features, building networks, and performing analysis on network datasets.

» The Network Analyst Window is designed to help users quickly and easily manage their network analysis layers and the network analysis classes (containing network locations and results). This is a dockable window in ArcMap.

» Networks used by ArcGIS Network Analyst are stored as network datasets (_ND) » A network dataset is created from the feature source or sources that participate in the network » It incorporates an advanced connectivity model that can represent complex scenarios, such as multimodal transportation networks » It also possesses a rich network attribute model that helps model impedances, restrictions, and hierarchy for the network » The network dataset is built from simple features (lines and points) and turns

» Cost ˃Measure and model impedances (mostly time or distance) ˃Can create custom “cost” fields, such as drive time (ex: Drive time = Distance / Speed limit) » Restrictions ˃One way streets, no pedestrians, construction zones » Hierarchy ˃Order assigned to network elements

» Multipoint routing » Add points dynamically or » Add points from an existing point layer

» Complex polygon generation » Allocation across networks

» Fixed and mobile asset routing » Emergency response

1.Prepare you data by calculating cost fields 2.Create the network database 3.Do your analysis

1.Obtain a street layer and clip it to your project area ˃Recommended to use Mapshare’s street data 2.Make sure it has a projected coordinate system (ex: UTM NAD 83 Zone 11N) 3.Add a field “METERS” (or appropriate map units for your layer) to calculate length using “calculate geometry” 4.Add and calculate field “MILES” 5.Add and calculate field WALK_MINS ˃Average pedestrian walking speed is 5km/h ˃5000 meters/60 minutes or 83 meters/minute ˃WALK_MINS = [METERS]/83 6.Add and calculate field DRIVE_MINS ˃SPEED_MPH / 60 = [miles per minute] ˃DRIVE_MINS = [MILES] /([SPEED_MPH]/60)

1.Prepare you data by calculating cost fields 2.Create the network database 3.Do your analysis

1.Prepare you data by calculating cost fields 2.Create the network database 3.Do your analysis