As president he saw that although improved, the roads were still inadequate so the Interstate highway system was born. Did you know that some of the roads were fashioned as secondary landing strips for aircraft including B-47s and BUFs? One of the modifying specs occurred in the late 50s when Atlas, Thor and Jupiter missiles were being manufactured in the Western US and then missiles were hauled on special truck beds to Cape Canaveral. Drivers reported that certain detours were needed to circumvent overpasses under which the missile carrier couldn't fit. Thus bridges were/are marked and as new bridges are built the trucking industry finds life easier.
I remember hearing that for every 7-10 miles of interstate (can't remember the exact number) 1 mile of it had to be in a perfectly straight line to be used for an airstrip for emergencies.