DESIGN OF ROAD JUNCTIONS AND VISIBILITY AT CORNERS(ROAD SAFETY AND THE TRAFFIC ENGINEERING) AND REQUIRED ADEQUATE SIGHT DISTANCE WITHOUT OBSTRUCTION:--

Traffic Engineering and road crossings are considered a best crossings, when the side road joins the major road at right angle. Junctions of lesser important roads with a more important one should be at right angles, and adequate provision should be made for visibility (line of sight) extending for a greater distance along the major road than along the minor road. When the minor road is of little importance relatively to be main road, or when both roads are unimportant, the crossing of the minor road should be staggered as shown in the illustration. When the side road is important but not sufficiently so as to justify a road about the baffle junction may be used by separate turning lanes (with an island in between the two) for the side road The two illustrations show the methods of alignment of new roads or re-alignment of the old roads. The radius of the kerb line at the junctions is 10.7 metres which is sufficient to enable even the largest vehicles to keep close to the kerb when turning. The additional space for manoeuvring and particularly for decelerating and accelerating with minimum interference with the flow of traffic on the major road, is provided by tapered widenings of the carriage way to the extent of 2.4 m in a length of 61 metres. Intersection of highways on sharp curves should be avoided if possible. It is also desirable to avoid vertical curves at intersections; no junction should occur at a change of grade. The whole of the junction area should be in one plane and as nearly as possible in that of the main road. Adequate sight distance must be provided along all roads and across their common corners. It is of first importance in the interest of road safety that the design of the roads layout (and those of the adjoining structures--building line) must provide for a clear line of sight to enable drivers of vehicles approaching the junction to have a full view of the traffic on the other road at a sufficient distance, to reduce speed if necessary