What's new in ArcGIS Network Analyst at 10
Location-allocation helps you choose which facilities from a set of facilities to operate based on their potential interaction with demand points. It can help you answer questions like the following:
- Given a set of existing fire stations, which site for a new fire station would provide the best response times for the community?
- If a retail company has to downsize, which stores should it close to maintain the most overall demand?
- Where should a factory be built to minimize the distance to distribution centers?
Point, line, and polygon barriers
Prior to ArcGIS Network Analyst 10, barriers were limited to points that restricted the entire network element they were located on. In ArcGIS 10, you can create point, line, and polygon barriers. You can also restrict travel through barriers or use them to temporarily change the cost of the underlying network elements.
- Point barriers: Using a restriction point barrier, you can choose to completely restrict the edge the barrier is located on or only restrict travel through the point barrier. Alternatively, you can create an added-cost barrier and incur a cost that you specify whenever the barrier is crossed.
- Line barriers: A restriction line barrier prohibits travel anywhere the line intersects the network. A scaled-cost line barrier increases or decreases the underlying cost of traversing the edges it covers by a factor that you specify.
- Polygon barriers: Like line barriers, polygon barriers restrict travel on the underlying edges or scale them by a factor that you specify.
Vehicle routing problem enhancements
The vehicle routing problem lets you add multiple breaks to each route. So, instead of only modeling a driver's lunch break, you can include a morning and afternoon break as well. Moreover, there are three break types designed to fit different break policies: time-window breaks, which are taken within a specified period of the day (for example, 10:00 a.m. to 11:00 a.m.); max-travel-time breaks, which occur before accumulating a specified amount of travel time; and max-work-time breaks, which occur before accumulating a specified amount of travel and service time.
Arrive and depart delays
A new field on the routes class of the VRP, ArriveDepartDelay, allows you to avoid having multiple vehicles stop at coincident orders.
No U-turns at network locations
Network locations, such as a stop on a route or an order on a vehicle routing problem, have a property for curb approach, which specifies the direction from which a vehicle may arrive and depart relative to the network location. A new option, No U-turn, was added. When this is chosen, a vehicle can approach the network location from either direction, but when it departs, the vehicle must continue in the same direction it was traveling when it arrived. This is especially useful when routing large vehicles that can approach the stop from either direction but can't turn around there.
Exclude restricted portions of the network when loading locations
By checking this option, which is a new property of network analysis layers, you can make sure that network locations are only placed on traversable portions of the network. This prevents placing network locations on elements that you can't reach due to restrictions or barriers.
New options for driving directions
The Inset Maps tab on the Directions Options dialog box has two new check boxes.
Rotate in Direction of Travel check box
Previously, the inset maps of driving directions were always oriented to the north. Now you can check this option to orient each inset map in the direction drivers will be facing when they begin the maneuver. This helps drivers understand maneuvers like left and right turns more quickly, since they don't have to mentally reorient the maps.
Show Maneuver Highlight Arrow check box
Choose this option to see arrows on inset maps.
Traffic affects travel times and varies by time of day and day of week. Moreover, traffic can change the path of the quickest route between two points. For example, if one route becomes clogged by rush-hour traffic, it may be quicker to take an alternate path that avoids the congestion. In ArcGIS 10, network datasets are able to model variable travel times based on historical traffic. As a result, the two analyses that support historical traffic (route and vehicle routing problem analyses) can produce more accurate travel times and determine the best routes for a given time of day and day of week.
Three-dimensional network datasets
Network datasets are now 3D enabled, which allows you to model and perform network analyses on interior pathways of buildings. In the graphic below, a route connects an office on the first floor of a building to an office on the third floor.
Using restrictions, you can perform analyses that avoid staircases for wheelchair-accessible routes or elevators for evacuation planning.
By connecting indoor pathways with z-aware street and sidewalk features, you can answer questions like the following:
- What floors of a high-rise building cannot be reached by a fire department within eight minutes?
- What is the shortest wheelchair-accessible route between rooms in different buildings?
When you create, edit, or delete any feature that participates in a network dataset, the network needs to be rebuilt to capture the changes. Previously, the entire network dataset would be rebuilt regardless of how small the changes were. Now the rebuilding process only rebuilds the network in dirty areas, which are areas immediately surrounding the edited features. This drastically reduces the time it takes to rebuild large networks.
Note, however, that when properties of the network dataset are edited, the entire network will still be rebuilt.
Modifying network dataset properties in ArcMap
Whenever you modify a network dataset using ArcCatalog, you need to close any ArcMap documents that are referencing the network dataset to remove schema locks. This is still true; however, since ArcMap has the new Catalog window, now you can use the network dataset and modify its properties from within ArcMap. It is not necessary to open and close ArcGIS applications to modify the network anymore.
Upgrade Network geoprocessing tool
If you have a network dataset from earlier ArcGIS releases, you will need to run this tool on the network to take advantage of the new functionality in the current release. If the network dataset is in a geodatabase, the geodatabase must be upgraded before the network can be upgraded.
Dissolve Network geoprocessing tool
The Dissolve Network geoprocessing tool creates a network dataset with fewer line features than the input network dataset.
Network datasets with fewer line features have more efficient traversals, which results in faster network analyses. The results of the analyses also contain fewer network elements, which also means that generating route geometries and driving directions are faster.
ArcGIS Server Network extension
Vehicle routing problem, location-allocation, and origin-destination cost matrix support
There are now server parameter coclasses and server results coclasses, available in SOAP and the GIS Server API, that work with the VRP, location-allocation, and OD cost matrix solvers in ArcGIS Server, to go along with the previously supported route, closest facility, and service area solvers.
Closest facility and service area support in REST
REST endpoints were introduced for closest facility and service area solvers.
Save layer on server
You can save the results of an analysis on the server and reuse the layer in subsequent requests to build on existing solutions.