An international inquiry carried out by the PIARC Technical Committee on Road Bridges has made it possible to collect information on current practice in nineteen countries for water drainage from road bridges (Australia, Austria, Belgium, Canada, Czechoslovakia, Denmark, France, India, Israel, Italy, Japan, the Netherlands, Norway, Poland, Spain, Sweden, Switzerland, the United Kingdom, the United States).

The fields covered are drainage of runoff water from the surface of the carriageway and roadside features (footways, etc.), of seepage water from the surfacing, under the waterproofing layer, by the channel, the gulleys and the collecting pipes, at expansion joints, at abutments.