ArcGIS 9.1 Network Analyst is a powerful extension that provides network-based spatial analysis, including routing, travel directions, closest facility, and service area analysis. Using a sophisticated network data model, users can easily build networks from their GIS data. ArcGIS Network Analyst enables users to dynamically model realistic network conditions, including turn restrictions, speed limits, height restrictions, and traffic conditions, at different times of the day. ArcGIS Network Analyst solves a variety of problems pertaining to spatial networks.

ArcGIS 9.1 Network Analyst allows users to define service areas with multiple rings.

Network-based spatial analysis is available for ArcGIS Desktop (ArcView, ArcEditor, or ArcInfo), ArcGIS Engine, and ArcGIS Server. For desktop users, ArcGIS Network Analyst provides a rich environment with easy-to-use menus, tools, and wizards. Developers building desktop applications will use the ArcGIS Engine Network extension, while developers building serverside GIS capabilities will use the ArcGIS Server Network extension.

Developers can build custom network applications on three deployment platforms (ArcGIS Desktop, ArcGIS Engine, and ArcGIS Server) and deploy applications on a variety of Linux, UNIX, and Windows operating systems. Since the underlying libraries of network components among the three platforms are common, development effort can be transferred easily.

Users of the previous version of Network Analyst will find all the familiar tools. In addition, ArcGIS 9.1 Network Analyst has improved the core functionality and added the ability to work within the new ArcGIS 9 geoprocessing environment, including ModelBuilder and scripting.

The Network Data Model allows for realistic data sets that account for multiple attributes, such as cost, restriction, and hierarchy. Users can define various cost attributes, such as distance, time, and visibility, according to their analysis requirements (see Advanced Modeling of Transportation Networks With ArcGIS 9.1 Network Analyst).

Multiple hierarchy levels that describe network classifications, such as highways, local major roads, and local streets, significantly improve performance on large networks while giving realistic analysis results.

The Network Data Model can include multipart turns that allow users to easily create complex turn maneuvers that will honor restriction rules, such as no U-turns and curb approach. Users can create and maintain network data sets in shapefile, personal geodatabase, and enterprise geodatabase formats. In addition, users can perform network analysis in spatial data catalog format.

For more information, visit www.esri.com/networkanalyst. Outside the United States, contact your local Esri distributor.