The Collaborative International Dictionary of English v.0.48:

overcrossing \overcrossing\ n.
   a bridge designed for pedestrians.

   Syn: footbridge, pedestrian bridge.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

overcrossing
    n 1: a bridge designed for pedestrians [syn: footbridge,
         overcrossing, pedestrian bridge]

Moby Thesaurus II by Grady Ward, 1.0:

39 Moby Thesaurus words for "overcrossing":
   Bifrost, bascule bridge, bateau bridge, bridge, cantilever bridge,
   carrefour, catwalk, cloverleaf, crossing, crosspoint, crossroad,
   crosswalk, crossway, drawbridge, floating bridge, flyover,
   footbridge, gangboard, gangplank, gangway, grade crossing,
   intercrossing, intersection, level crossing, lift bridge,
   overbridge, overpass, pontoon bridge, rope bridge, rotary, span,
   stepping-stone, stepstone, suspension bridge, swing bridge,
   toll bridge, traffic circle, undercrossing, viaduct