I am looking for a way to determine the route between two points using a road network. A little background...I have 1200 beginning and ending points from two separate datasets, related through a unique ID. I've created polylines between them using the 'XY To Line' tool. However, this of course returns the straight line between these two points...aka "as the crow flies." This information would be much more beneficial to me if the connecting lines were based on a road route (like interstates and state hwys). I do have a network and business analyst extensions available to me. Where should I start? Where is a good place to find a general interstate/us hwy/primary road dataset? Can I accomplish this task with geoprocessing tools? Is there a way to automate the 1200 routes with a batch process? Basically, we are searching for highway corridors where trucking is concentrated to determine possible locations for future distribution hubs.