I have a road network downloaded from Ordnance Survey (Meridian 2, with A roads, B roads and Minor roads Merged into one shapefile and then built into a Network Dataset for use in ArcGIS' Network Analyst) and would like to use it to determine Service Areas for 4 hospitals (preferably with drive times of 30 minutes and 60 minutes) and Closest Facilities (same 4 hospitals and directions from 539 points).
I've used the Network Dataset to find the Service Area and the Closest Facility but the only parameter I can use is distance (metres).
Question: How do I set up the network to use drive time, not distance, and work out Service Area by, say, 30 minutes?
When I try to create the Network Dataset from the downloaded road network, I try to add Drive Time as an Attribute but I can't get the Network Dataset Wizard to accept the evaluators.
I've tried to follow the ESRI help pages and I've Googled around but I'm lost. I'm not sure what the time setup should be or if it's something I can just do or something I need to set up from the start.
Best Answer
In order to calculate the drivetime attribute, you would need to have a distance of a road link (which you already have) and a KPH value (the speed value). Esri has a set of great tutorials for Network Analyst where you can learn more about building a network dataset.
I also usually recommend for those who get started with the network data (especially with custom datasets, not obtained via big vendors like Navteq or TomTom) to go through a very concise yet comprehensive tutorial on building a network dataset from scratch where all the relevant concepts are described and you have a set of exercises to go through.
Prepare data for use with the Network Analyst extension