Road maintenance is work that takes place on bonding between two layers of binder

roads from motorways to unclassified roads to course and must be thin, uniformly cover
ensure they remain strong, safe and efficient. the entire surface, and set very fast.
the overarching aim is to keep road users safe,  BASE COURSE
manage traffic and maintain upkeep.  Asphalt concrete layer that distributes
As defined by AASHTO; “Maintenance is the the load to the base. It is made of
preservation and keeping of each type of aggregates with less asphalt content
roadway, roadside, structures and facilities as than the wearing resistance.
nearly as possible in its original condition as  PRIME COAT A prime coat is applied by
constructed or as subsequently improved the spreading low viscous cutback bitumen
operation of highway facilities and service to to an absorbent surface like granular
provide satisfactory and safe transportation.” bases on which the binder layer is
HIGHWAY PAVEMENTS a path with a hard placed. It is primly used to provide a
surface on one or both sides of a road, that bond between two layers. A prime coat
people walk on. is able to penetrate into the below
Two Types of Pavements: layers, plug the voids, and form a
Flexible Pavement - Bituminous pavement watertight surface.
Rigid Pavement - cement concreted roads  BASE
RIGID  It is generally constituted by hard and
Life- long life max 30 years durable particles such as crushed rock.
Cost - High Provides an additional load distribution
Maintenance – Low and contributes to drainage.
FLEXIBLE PAVEMENT  SUB-BASE
Life - Short  It is a layer of material below the base
Life Max 15 Years course. Its major role is to provide
Cost - Low structural support, improve drainage,
Maintenance – High and reduce the intrusion of fines from
FLEXIBLE PAVEMENTS are constructed from the subgrade in the pavement structure.
bituminous or unbound material and the stress is  SUBGRADE
transmitted to the sub-grade through the lateral  It is the base of all pavement layers. All
distribution of the applied load with depth. the above pavement layers transfer the
THREE MAJOR TYPES OF FLEXIBLE stress to this layer. It should be properly
PAVEMENT compacted to the desired density, near
01 Conventional layered flexible pavement the optimum moisture content.
02 Full-depth asphalt pavement  FULL-DEPTH ASPHALT PAVEMENTS It
03 Contained rock asphalt mats (CRAM) is constructed by placing bituminous
Conventional flexible pavement uses the layered layers directly on the soil subgrade.
system. High-quality materials are placed at the These types of pavements are most
top of the pavement layer to resist maximum suitable when there is high traffic and
stress and low-quality cheap materials are local materials are not available
placed in lower layers.  CONTAINED ROCK ASPHALT MATS
PAVEMENT STRUCTURE (CRAM)
The seal coat is a thin layer with a water-proof  It is constructed by placing dense/open-
surface and provides skid resistance. graded aggregate layers in between two
WEARING SURFACE WEARING- asphalt layer asphalt layers. Properly designed
in contact with traffic. Resists the traffic loads , asphalt concrete is placed above the
provides a regular surface , waterproofing, and subgrade.
slipping resistance. This asphalt concrete will reduce the vertical
 TACT COAT a little amount of asphalt is compressive strain on the soil subgrade and
applied to the surface. It is generally an protect it from surface water.
asphalt emulsion diluted with water. Its Pavement failure may occur due to various
main function is to provide proper factors such as excessive vehicular stress,
sunlight exposure, water intrusion, unequal degradation of the topmost asphalt
expansion and contraction due to seasonal layer.
changes, etc. Highway maintenance- function of preserving
 Alligator cracking is associated with load repairing restoring highway
and structural distress. These cracks are  To preserve the road in its originally
extensively found at intersections where constructed condition,
the vehicles are stopped for a relatively  To provide user safety and efficient,
long period because these cracks start convenient travel along the route
to form when the subgrade and base
compress due to the excessive imposed Physical maintenance- Activities such as
wheel load. sealing, patching, filling joints, etc.
 Block cracking forms a box-like crack on Traffic service activities- Including painting
the surface. pavement marking, removing snow, ice and litter.
 Linear cracking or longitudinal cracking Rehabilitation - includes restoring or betterment
is a common type of crack, seen parallel of roadway such as resurfacing.
to the roadway. TYPES OF MAINTENANCE
 Edge cracking is usually formed at the Surface Maintenance.
edge of highway pavements. These  Roadside and drainage maintenance.
cracks are typically associated with the  Shoulder and approaches maintenance.
ingress of water in underlying layers  Snow and ice control.
 Potholes are the type of flexible  Bridges maintenance.
pavement failure that can be seen as  Traffic service.
small depressions on the surface of the
pavement and can penetrate deep up to CONCLUSION
the base course. These are generally  Highway pavements play an important
associated with infiltration and also role in convenience, warning and
result from alligator cracks if not treated direction.
properly.  There should be a better management
 Depression indicates the area on the from time to time to keep pavements in
surface of pavements that has a slightly good condition.
lower elevation than the surrounding  The design of pavements should be
areas. They become prominently visible upgraded for better climate resistance.
after rainfall due to the accumulation of
water. Roadway
 Rutting A type of pavement failure that FIRST and most common mode of
results in the formation of channelized transportation in logistics
depressions particularly in the wheel  MOST versatile of the four main modes
track of pavement. W ith time, the wheel with least geographical constraints
of heavy vehicles starts to compact the  only mode that transforms door to door
asphalt surface thereby forming ruts. deliveries
 Corrugations refer to the distresses that  offer high speed of travel but have limited
occur at regular intervals in the form of Accessibility
ridges and valleys on the surface of the
pavement. They run along the direction Waterways
of the pavement itself and are usually  slowest mode of transportation
less than 5 feet. Similar distresses that  most efficient for the amount of cargo they
run perpendicular to the traffic are are carrying.
known as shoving.  considered to be the only connection
 Raveling It is the type of pavement between far-off places for transportation of
failure that occurs due to continuous both people and goods.
ingress of water thereby causing
Airways-  NEWEST mode of transportation
 fastest growing and most time efficient affected by age. Glare recovery time is the time
shipping mode required to recover from the effect of glare after
 considered to be the most expensive way the light source is passed, and will be higher for
to ship elderly persons. Color vision is important as it
 help in connecting remote places in difficult can come into picture in case of sign and signal
terrain recognition.

Railways-  FIRST invented for use in the 19th Walking The most prevalent of the road users
century are the pedestrians. Pedestrian traffic along
 has played a pivotal role in the realm of footpaths, sidewalks, crosswalks, safety zones,
logistics for over two centuries islands, and over and under passes should be
 confined to a more limited infrastructure considered. On an average, the pedestrian
 are costly and time consuming to construct walking speed can be taken between 1.5 m/sec
to 2 m/sec. But the influence of physical, mental,
Reaction time The road user is subjected to a and emotional factors need to be considered.
series of stimuli both expected and unexpected. Parking spaces and facilities like signals, bus
The time taken to perform an action according to stops, and over and under passes are to be
the stimulus involves a series of stages like: located and designed according to the maximum
Perception- is the process of perceiving the distance to which a user will be willing to walk. It
sensations received through the sense organs, was seen that in small towns 90 percent park
nerves and brains. It is actually the recognitions within 185 m of their destinations while only 66
that a stimulus on which a reaction is to happen percent park so close in large city.
exists. Intellection- involves the identification and
understanding of stimuli. Emotion- involves the Vehicle Users It is important to know about the
judgment of the appropriate response to be vehicle characteristics because we can design
made on the stimuli like to stop, pass, move road for any vehicle but not for an indefinite one.
laterally etc. Volition- is the execution of the
decision which is the result of a physical actions Turning radius and turning path The minimum
of the driver. turning radius is dependent on the design and
Reaction time For example., if a driver class of the vehicle. The effective width of the
approaches an intersection where the signal is vehicle is increased on a turning. This is also
red, the driver first sees the signal (perception), important at an intersection, round about,
he recognizes that is a red/STOP signal, he terminals, and parking areas.
decides to stop and finally applies the brake
(volition). This sequence is called the PIEV time Visibility The visibility of the driver is influenced
or perception-reaction time. by the vehicular dimensions. It should be clear
even in bad weather conditions like fog, ice, and
Visual acuity and driving The perception-reaction rain; it should not mask the pedestrians, cyclists
time depends greatly on the effectiveness of or other vehicles Equally important is the side
driver’s vision in perceiving the objects and and rear visibility when maneuvering especially
traffic control measures. The PIEV time will be at intersections when the driver adjusts his
decreased if the vision is clear and accurate. speed in order to merge or cross a traffic stream.
Visual acuity relates to the field of clearest Rear vision efficiency can be achieved by
vision. The most acute vision is within a cone of properly positioning the internal or external
3 to 5 degrees, fairly clear vision within 10 to 12 mirrors.
degrees and the peripheral vision will be within
120 to 180 degrees. This is important when Braking performance The braking performance
traffic signs and signals are placed, but other and deceleration characteristics of vehicles are
factors like dynamic visual acuity, depth of prime importance. The time and distance
perception etc. should also be considered for taken to stop the vehicle is very important as far
accurate design. Glare vision and color vision as the design of various traffic facilities are
are also equally important. Glare vision is greatly concerned.
 a driver tends to follow the same pavement color
1. Safe stopping sight distance: includes both having driven by some distance on a light or
the reaction time and the distance covered in dark
stopping. surface, he expects to remain on a surface of
Thus, the driver should see the obstruction in that same color until he arrives a major junction
time to react to the situation and stop the point.
vehicle.  Night visibility
2. Clearance and change interval: are related to - the traffic designer must strive to improve night
safe stopping distance. All vehicles at a distance time visibility in every way he can.
further  Geometric aspects
away than one stopping sight distance from the - pavement slope, gradient and right of way
signal when the Yellow is flashed is assumed to affect transportation in various ways.
be - minimum lane width should be provided to
able to stop safely. Such a vehicle which is at a reduce the chances of accidents.
distance equal or greater than the stopping sight - right of way width should be provided, if it will
distance will have to travel a distance equal to become less, future expansion will be difficult
the stopping sight distance plus the width of the and
street, the development area will be adversely affected.
plus the length of the vehicle. Thus the yellow - gradient should also be provided to reduce the
and all red times should be calculated to tractive effort of large vehicles.
accommodate
the safe clearance of those vehicles. • Highway Engineering is an engineering
3. Sign placement: The placement of signs again discipline which involves the design,
depends upon the stopping sight distance and construction and
reaction maintenance of Highway Roads & Systems.
time of drivers. The driver should see the sign • Older techniques include signs, signals,
board from a distance at least equal to or greater markings and tolling.
than • Newer technologies involve intelligent
the stopping sight distance transportation systems including advanced
traveller information
Road surface Factors relating to road surface systems (eg., variable message sign) advance
like road roughnessm, tire wear, tractive traffic control systems (eg., ramp meters) and
resistance, noise, light reflection, should be vehicle
given special attention in the design, infrastructure integration.
construction and maintenance of highways for
their safe and economical operation. Traffic Engineering has an ultimate goal of
multimodal transportation network to ensure the
Lighting Illumination is used to illuminate the safe and efficient movement of people and
physical features of the roadway and aid in the goods on roads and highways.
driving task. Luminare is a device that distributes
light into pattern. The transportation is vital in every aspect of life

Roughness - one of the main factors that an

engineer should give importance during the
design, construction and maintenance of a
highway system. - highway where the texture of
the surface is smooth, tends to seek by the
driver. -shoulders or even speed change lanes
may be deliberately roughened as a means of
delineation.

 Pavement factors