748.7 Bridge Deck and Bridge End Drainage
Bridges are provided with a combination of slab drains and drain basins to drain the bridge deck. Bridge Division will determine the placement of slab drains. Drain basins should be provided on the down-grade side of all bridges. Consideration should be given to providing drain basins on the up-grade side of bridges where the roadway has curb and gutter and there is a possibility of a significant volume of water being carried onto the bridge. Where interchange ramps with curb are involved at the end of a bridge, consideration should be given to carrying bridge drainage along the ramp curb to an outlet on the ramp in lieu of using curb and gutter or drain basins at the concrete approach pavement. The drainage facility beyond the limits shown in the standard plans is designed to meet the existing conditions at the bridge involved, and is generally shown on the culvert section sheets. The district should make a recommendation for handling drainage when submitting bridge survey reports for concurrence by the Bridge Division at the bridge field check or on the bridge field check memorandum.