A single-panel color image display apparatus includes a plurality of switchable color filters selectively transmitting andor reflecting a plurality of color light beams. The conductive connection may include conductive bumps attached to the strap, andor may include conductive traces, such as a conductive ink traces. By simulating a second bivalent output at the detector card level, a conventional field controller is capable of estimating the vehicular speed from a single wire-loop sensor.