At locations where the study is extended into or through an incorporated city or town, the zone should be broken at the city limit, whether or not the zone speed changes. This is necessary because the speed limits inside the limits of an incorporated city or town may be established by the city government, while the speed limits outside the corporate limits of a city or town must be established by the Transportation Commission.

It is also necessary to show on the strip map the precise location of the city limit by milepoint and control section to prevent misinterpretation of the zone when the city limit is changed. The zone speed of any adjoining map should always be shown.

In the event the city limit is changed, the strip map and Transportation Commission minute order should be revised to show the new city limit.