the generation of all subsequent alternate routes between that same route origin and route destination with a cost inflation factor of 20 applied to the selected edges a new least cost route is generated if that new route virtually duplicates the original route it will do this when all alternative routes are much more costly the cost inflation factor is doubled if the new route partially duplicates the previous route the cost inflation factor is still increased but by a proportionately smaller amount the particular means used to estimate the amount of duplication described in detail in fig1 is to compare the actual cost penalty incurred by the alternate route to an estimate of the cost penalty it would have incurred had it followed a previous route that ratio is then applied directly to the cost inflation factor if the new route duplicates less than 70 of the original route the new route becomes the first alternate route if duplication exceeds 70 however the new route is regenerated once using the increased cost inflation factor and the regenerated route becomes the first alternative route instead to the extent that the regenerated route re uses edges from the earlier two routes the cost inflation factor is again increased each time another alternative route is desired the current value of the cost inflation factor is first applied to any edge utilized by the middle 90 of the original route or utilized by the middle 90 of any previous alternative route and then a new route is generated each time a new route is generated the cost inflation factor is increased further with the magnitude of the increase reflecting the extent to which the new route re uses edges employed by earlier routes as with the first alternate route 70 duplication of previous.