An in aircraft computer renders graphical representations of airfield range marker extensions to a runway extended centerline, even when the runway extended centerline is not rendered. Crossbars of the runway extended centerline are extended as arc segments to the center of the display with chevrons indicating the relative location of the airfield. Distance marker billboards are replicated at the end of the extended arc segments. As the aircraft approaches the airfield, crossbars closer to the airfield are extended. Vertical markers maintain billboards corresponding to range rings around an airfield in a visually prominent location, even when the proximal portion of such range ring is not visible in the display.