What's new in the ArcGIS for Server Network Analyst extension
The ArcGIS for Server Network Analyst extension offers several improvements at 10.1. Live traffic capabilities were added, so now you can use current traffic conditions for visualization and network analysis purposes. Also, geoprocessing tools that facilitate creating and working with service-area and vehicle-routing-problem web services were added. These enhancements, as well as others, are described in the subsections below.
Solve larger network problems with 64-bit ArcGIS Server
Several kinds of network analyses push the limits of the computer resources due to the sheer quantity of network elements and attribute values that are processed. Because ArcGIS Server is a true 64-bit application at 10.1, the limits have been raised significantly, and now it is possible to solve much larger network analyses.
Generate service areas faster by using a network's hierarchy
The time to generate a service area was drastically improved in ArcGIS 10.1 because service areas now support using the hierarchy of a network dataset as they solve. This reduces the number of roads that must be searched in the solve process and therefore makes generating a service area much faster.
Generate Service Areas geoprocessing tool
ArcGIS 10.0 and prior versions allowed you to create web services that solved service area problems; however, the new Generate Service Areas geoprocessing tool simplifies and streamlines this process.
Prior to 10.1, you needed to add the Make Service Area Layer tool to a model, know which other geoprocessing tools to add to the model, and know the proper sequence in which to link them. Now you only need to use one tool, Generate Service Areas, then publish the results of the tool. Another benefit of the new tool is that the input and output data formats simplify managing the data in a web environment.
Solve Vehicle Routing Problem geoprocessing tool
A new VRP geoprocessing tool, Solve Vehicle Routing Problem, is included with the ArcGIS 10.1 Network Analyst extension to facilitate the process of authoring, publishing, and managing data for VRP web services.
Solve Vehicle Routing Problem provides benefits over Make Vehicle Routing Problem Layer that are similar to the benefits of Generate Service Areas over Make Service Area Layer. Make Vehicle Routing Problem is still the tool of choice when creating network analysis layers for use outside of ArcGIS Server; however, Solve Vehicle Routing Problem should be used when publishing a VRP service. Solve Vehicle Routing Problem lets you configure and publish the results of a single tool rather than multiple tools in a model. Also, the inputs and outputs of the new tool are of data types that make handling the web service's data simpler.
Live traffic data
The ArcGIS Network Analyst extension at 10.1 can incorporate live traffic data, which makes it possible to:
- Visualize current traffic conditions on a map
- Solve any network analysis using live travel speeds
The live traffic model builds on the historical traffic model, which was released with 10.0. Historical traffic provides travel times that vary depending on the time of day and day of the week. The times are based on historical averages. Performing a network analysis using historical traffic data returns more accurate results than those returned using an effortless, static cost attribute. Live traffic fills in where the historical traffic model falls short: accounting for current traffic conditions. When you solve a network analysis based on the current time, using live traffic will tend to improve results, even over those created using historical traffic.
Learn more about modeling traffic in the network dataset
Update Traffic Data geoprocessing tool
Update Traffic Data was added to support the live traffic model. It downloads live traffic data from a data provider's web service and stores the data in a file format that network datasets can read. You can set up this tool to periodically download data and create dynamic traffic format (DTF) files so that your maps and network analyses use current travel speeds.
Update Traffic Incidents geoprocessing tool
This tool downloads traffic incidents, such as vehicle accidents and construction work, from a data provider and creates a point feature class of the incidents. Overlaying incidents on a map of live traffic provides insight into why travel speeds are slower than normal. This tool is typically configured to write to an enterprise geodatabase so that the incidents can be viewed or shared as a map or feature service while still being periodically updated.
Support for traffic data in all solvers
In 10.0, historical traffic was introduced, but it was supported by just two of the six solvers: Route and Vehicle Routing Problem. Now the other solvers (Service Area, Closest Facility, OD Cost Matrix, and Location-Allocation) also support traffic data; furthermore, they all support live traffic along with historical traffic.
The Network Analyst module (Python)
The Network Analyst module is a Python module that provides access to all of the geoprocessing tools available in the Network Analyst toolbox as well as helper functions and classes. You can use this module with other ArcPy modules to automate workflows using Python.
Support for Python scripts in evaluators
Previously, the field and VBScript evaluators only supported VBScript. Now these evaluators support scripts written in Python. This is especially important on ArcGIS Server for Linux since VBScript is no longer supported by that platform. Accordingly, VBScript evaluators are now referred to as script evaluators.
Copy Traversed Source Features geoprocessing tool
Copy Traversed Source Features creates two feature classes and a table, which together contain information about the edges, junctions, and turns that a solved network analysis layer traversed.
After performing a network analysis, you might want to study some aspect of the underlying network using this tool. For example, once you have generated several routes in a study area, you can use Copy Traversed Source Feature to help you determine the number of times a particular street segment was traversed.
Better support for real-time routing of moving vehicles
Loading network locations into a network analysis layer can account for the bearing and bearing tolerance of the input points so that they are placed more accurately on the network. This feature is especially useful when loading GPS data from moving vehicles into a network analysis.