Interesting business rule for oversize vehicle routing -- any ideas?

Discussion created by robertlindquist on Dec 10, 2010
Latest reply on Dec 10, 2010 by robertlindquist
We are developing an application to route oversize vehicles (on a Navteq network dataset), and there is an internal business rule which affects how routing is allowed around obstructions i.e. an overpass on a freeway.  If the vehicle cannot pass under the structure, it obviously must use an alternate route ... it must exit the freeway.  The internal rule is: the vehicle cannot simply exit and then immediately use the on-ramp to return to the freeway (they call it ramp-to-ramp bypass of an obstruction).  The vehicle is allowed to return to the freeway at some other entrance point farther along.  Regardless of the logic of this rule, it is one we must attempt to enforce.

The question is:  anyone have any ideas about how to best achieve this?  We can't restrict use of the on-ramp ( a vehicle may be entering from some intersecting road and thus not be breaking the rule).  What we need to try to do is, figure out a way for the vehicle to leave the freeway and then return in the most expeditious way without using the on-ramp immediately opposite the off-ramp that he used.