The Drivetime web service uses the latest road networks and fast search algorithms to show the buffer boundaries in time (isochrone) or distance (isodistance) from a specified location. These buffers are different from other MapInfo Pro object or table buffers because they are based on road networks and not straight line distances. Driving region time and distance buffers are calculated based on the speed limits of the individual roads and highways in the road network and the distance or time values you request. Isochrones and isodistances are collectively called isograms.
You can only access this Drivetime data and calculation functionality on an Envinsa 4.0 routing server. The Driving Regions web service helps you create isochrone and isodistance buffers using points in your own data.
An isochrone or a time buffer is a region that shows the area that a driver can reach from a starting point in a specific amount of time based on the speeds specified in the routing network. For example, if you wanted to put together an event and invite the customers who live within an hour's drive of the event site, you could create a time buffer for known customers within an hour's drive. The service would then use the average driving speeds defined in the road network to calculate the time buffer from your event. You can then display your data within those buffer regions using a Select or SQL Select statement.
An isodistance or a distance buffer is a region that shows the area that a driver can reach from the starting point in the same distance. For example, if you want to contact all of the customers who live within 50 miles of the event instead of one hour, you could calculate the distance using the Drivetime web service, using similar logic.
Effectively, you are creating buffers from a point or table of points based on the server's road network for specified times or distances. Using the Driving Region service options, you can control the way this information displays and the number of time and distance buffers you create at a time.
For more information, see Creating Time or Distance Buffers for a Table and Rules when Adding a Driving Value.