Abstract: A modular overpass that uses interlockable roadway units. These interlockable units include ramp units adapted for fitting together to create entry and exit ramps having a low end and a raised end, cantilever units for attachment to the raised ends of the ramps, and suspended span units for joining the cantilever units. Flexible footings are provided to support the roadway units. The flexible footings comprise a resilient base, a covering cap sealably fitted over the base to define a cavity, and a packable bearing material partially filling the cavity. A system of pilings are used to anchor the roadway units in position. The system can be used to create an overpass over intersections between highways and secondary roads so that highway traffic travels over the overpass and local secondary road traffic is controlled by traffic lights. The modular overpass is shaped to conform to the existing highway surface and is supported on that surface by the flexible footings.