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Hello Engineers,

The role of delineators is to provide visual assistance to drivers about alignment of
the road ahead, especially at night. Delineators are particularly effective in the case of complex
locations involving changes in horizontal/vertical geometry, and during severe weather conditions
such as heavy rain, fog or snow. Normally, reflectors are used on the delineators for better night
time visibility.
1.2 In a broad sense, “delineation” stands for any device or treatment whose aim is to
outline the roadway or a portion thereof. This could include painted lines, raised pavement
markers, posts, post-mounted reflectors or contrast treatments of the pavement. Delineation by
pavement markings is covered by IRC:35, “Code of Practice for Road Markings”. This code deals
only with post type retro reflective delineators or embedded on any concrete structures/trees
Delineators are classified under three types:
(i) Roadway Indicators
(ii) Median Markers
(iii) Hazard Markers, and
(iv) Object Markers
2.2 Each of these serves a somewhat different purpose. “Roadway indicators” are intended
to delineate the edges of the roadway to guide drivers about the alignment ahead, particularly
where it might be confusing for some reason. The objective of “hazard markers” is to define
obstructions like guard-rails and abutments adjacent to the carriageway, for instance at culverts
and bridges which are narrower than the roadway width at approaches. “Object markers” are
used to indicate hazards and obstructions within the vehicle flow path, for example channelizing
islands close to the intersections, roundabouts at the intersections or electric poles or trees
located within the Right of Way (RoW).
2.3 At the same time, it is to be borne in mind that the delineators are basically driving
aids and should not be regarded as a substitute for warning signs, road markings, or barriers for
out-of-control vehicles
Roadway indicators are popularly called as Delineators or Guide Poles. It is basically
a form of guide posts made of Mild steel with pure polyester powder coating with the minimum
thickness of powder coating of not less than 40 micron for protection against corrosion. The
surface should be concealed so that there should not be any exposed surface without powder
coating. Alternatively, these metal guide poles can be concealed with thermoplastic body which
is of course somewhat cost prohibitive. The posts shall have an ellipsoidal or circular design
with the height of the pole shall be 800 to 900 mm above the ground with about 200 to 300
mm base which can be anchored onto the ground. Mild steel Guide Poles shall conform to
Type XI sheeting specifications as per IRC:67 and ASTM D 4956 which would ensure to obtain
clear visibility of the road alignment during night time (
As a general rule, roadway indictors should be erected at the edge of the usable
shoulder and in the case of kerbed sections at a distance of 0.6 m from the kerb face. On
hilly terrains, they may be placed either on the parapet or at the edge of the earthen shoulder
depending on the available roadway width and Right of Way (RoW)
Flexible Median Marker (FMM) should be used for improving median visibility during dark hours.
Use of Median Marker provides safety against collision happening with medians during night time
or severe weather. Flexible Median Markers shall be provided with fluorescent yellow colour retro
reflective sheeting Type XI as per IRC:67. Flexible Median Marker shall be of tough, high impact
resistant, injection-molded, thermoplastic body with property of flexibility to provide high durability
and U shape structure having rebound/bounce back property
The following designs shall be adopted for hazard markers:
The striped markers consisting of alternating black and yellow stripes sloping downward at an
angle of 45° towards the side of the obstruction on which the traffic is to pass (see Fig. 9).
Hazard marker to be made with Type XI sheeting conforming to

These OHM should be erected immediately ahead of the line of obstruction, for
instance on a narrow bridge just where the bridge rail starts. When placed in conjunction with the
guard-rail on a bridge approach, the OHM should be located immediately behind the guard-rail
and at sufficient height to ensure that these will be properly visible to the oncoming traffic. The
inside edge of the OHM should be in line with the inner edge of the obstruction as far as possible
This Aluminum-backed flexible prismatic sheeting shall be made of yellow colored
flexible prismatic sheeting with non-metallic prismatic lens formed in a transparent, synthetic
resin as retro reflective elements. This flexible prismatic sheeting shall have black and yellow
stripes with aluminum backed flexible prismatic.