MapInfo Pro Spectrum on Demand DriveTime creates circles instead of expected isochrone shape

Products Affected: MapInfo Pro™


When using MapInfo Pro Spectrum On Demand and creating DriveTimes using the "major highways only" option,  the resultant Drivetime regions are circles and not the expected isochrones shape typically returned for DriveTimes.


Specturm On Demand in MapInfo Pro uses the PB product "Routing J Server" (RSJ).
In RJS there are two types of road networks, a Major Road network and a Minor road network. The major roads mainly consist of Highways etc.

The "major_road" option in RJS is a Boolean value (i.e. yes or no), so if the "major_road" option is true, the route between two given points or boundary on a given point should be calculated based on the major road network only. 
The minor roads will not be considered in a Boundary or route calculation.

If the the designated point used to build the Drivetime doesn't fall on or is disconnected from the major road network, traversing or driving would not be allowed for that point and a Circular shaped object is produced for the results.


UPDATED: July 23, 2019
The solution is to uncheck the Use Major Roads Only check box or create drivetimes based on point locations that are closer to the major roads network.