Assignments must be made considering logical routings, available
roadway capacities, left turns at critical intersections, and projected
(and perceived) minimum travel times. In addition, multiple paths
should often be assigned between origins and destinations to achieve
realistic estimates rather than assigning all of the trips to the
route with the shortest travel time. The assignments must be carried
through the external site access points and in large projects (those
producing 500 or more additional peak direction trips to or from the
site during the development's peak hour) through the internal
roadways. When the site has more than one access drive, logical routing
and possibly multiple paths should be used to obtain realistic driveway
volumes. The assignment should reflect conditions at the time of the
analysis. Assignments can be accomplished either manually or with
applicable computer models.