DRAINAGE OF LEVEL OR NEARLY LEVEL ROADS

This report considers the drainage of surface water from roads of constant crossfall. Two systems are studied:- 1. A channel of constant depth along the lower edge with outlets at regular intervals and 2. A channel formed by a raised kerb again with outlets at regular intervals. The results in the report are based mainly on theoretical considerations though these are co-ordinated with practical measurements. They apply mainly to level or nearly level roads and supplement the results given in an earlier report LR 277 "The Hydraulic Efficiency and Spacing of Road Gulleys". The theoretical equations are comparatively complex and not suitable for use in design offices and so the results have been analysed statistically to give a simpler formula. Tables are provided which give the solutions of this latter formula for a wide variety of conditions. /Author/