Owing to the huge damage caused by flash water and torrents in the desert roads, the attempts to prevent such damage has received a great attention. Culverts are the popular engineering tool usually used for converting the accumulated runoff water from one side of the desert roads to the other side. This engineering tool prevents overtopping which stops the safe traffic stream over the roads. Since the culvert entrance geometry is one of the prime factors affecting its accurate performance. The present study is a trial for increasing the discharging efficiency of such culverts to give more safety for the desert roads. Investigating the influence of using inclined headwall at the culvert entrance on discharge efficiency, its inclination angle in the same direction of the flow and in the opposite direction will be tested as well. A needed survey of references related to the current study topic, covers a suitable time period were included in a tabulated form, with the needed technical comments. The theoretical approach also was introduced. A comparative study was done for the results obtained by most popular researchers and the calculated discharging efficiency reached by each of them, and given in a tabulated form.