Components of a
Road Structure
Engr. Ralph Angelo Estiller
CSU- College of Engineering
Components/Elements of Road System
◦ Carriageway
◦ Shoulder
◦ Margin
◦ Roadway
◦ Right of Way
◦ Median
◦ Guardrails/Traffic Barriers
◦ Camber
◦ Kerbs
◦ Bicycle and Parking Lanes
Carriage way
We have two types of carriageway
Single Carriage way
◦ A single carriageway or undivided
highway is a road with 1,2, or even
3 lanes arranged within a single
highway with no structures on the
center to separate the opposite
flow of traffic
Dual Carriage way
◦ Dual Carriage way or divided
highway is a class of highway
with carriage way for traffic
travelling in opposite directions
separated by a central
structure.
Shoulder
It is an emergency stopping
lane by the verge of a road
or motorway.
◦Margin
Margin
It is the small portion of the
road provided after shoulder
◦Roadway
combination of carriage way
and shoulder
Right of Way
the whole width of road. It is the combination of carriageway, shoulder, margin, and
other components of the road.
Median
could either be an island or any traffic barriers such as concrete barrier or plastic.C
◦ It is the reserved area that
separates opposing lanes
of traffic on divided
roadways
Guardrails
are fixed structures provided at the edge of road shoulders to prevent vehicles from
riding out of roads especially on curves.
Kerbs
it is the dividing line between carriageway and footpaths.
Bicycle Lanes
It is the portion of a roadway designated
for exclusive used of bicycles and other
non-motorized vehicles
Parking Lanes
an additional lane provided on urban
roads & streets for on-street parking
Bus Bays
provided lanes for Bus use.
Footpath or Sidewalk
◦ Is a exclusive right of way for
pedestrians especially in urban
areas.
◦ They provided to ensure safety of
pedestrians
◦ Minimum width is 1.5 m
Camber
it is the slope provided on the road surface in the transverse direction to drain-off
rainwater from the road surface.