INTERSECTIONS & ITS TYPES: - At
the intersection there are through, turning and crossing traffic and these
traffic movements may be handled in different ways depending on the type of
intersection and its design. Intersection may be divided into two groups:
[1]
Intersection at grade: - These
include all roads which meet at more or less the same level. The traffic
maneuvers like merging, diverging and crossing are involved in intersection at
grade. These intersections may be further classified into Unchannelized,
channelized and rotary intersections.
(i) Channalized intersection: -Channelized intersection provides
more safety and efficiency. It reduces the number of possible conflicts by
reducing the area of conflicts available in the carriageway.
(ii) Unchannalized Intersection: - The
intersection area is paved and there is absolutely no restriction to vehicles
to use any part of intersection area. Hence the unchannalized intersections are
the lowest class of intersection, easiest in the design.
(iii)
Rotary Intersection: -
Rotary Rotary intersections or
round abouts are special form of at-grade intersections laid out for the
movement of traffic in one direction around a central traffic island.
[2] Grade separate intersections: - Grade separated intersection design is
the highest form of intersection treatment. This type of intersection causes
least delay and hazard to the crossing traffic and in general is much superior
to intersection at grade from the point of view of traffic safety and efficient
operation.