Introduction of Highway Highway Engineering C3010 / UNIT 1/
INTRODUCTION OF HIGHWAY ENGINEERING
OBJECTIVES
General Objective
To understand the development and transportation system in Malaysia.
Specific Objectives
At the end of the unit you should be able to :- state the construction structure used in transportation system. identify the related profession in the road construction development. describe the history of road development. describe the road category. identify the related agencies involved in road construction.
1
UNIT 1UNIT 1
Introduction of Highway Highway Engineering C3010 / UNIT 1/
1.0Introduction
For rapid economic, industrial and cultural growth of any country, a good
system of transportation is very essential. Transportation system comprises of
good network of roads, railways, well developed water ways and airways.
Airways and water ways although help to some extent in transportation within the
country, but they are the modes of transport mainly with foreign country.
Railways and highways also to some extent help in transport with foreign
countries but their main concern is within the country itself.
2
INPUT
CONSTRUCTION STRUCTURE FOR TRANSPORTATION
Introduction of Highway Highway Engineering C3010 / UNIT 1/
1.0.1 Different modes of transportation
Man has always been curious for new inventions. In the early days
of civilization it was thought that the movement of any human being can
be on the earth only. No one thought of flying in air or cruising in large-
oceans.
Modes of transportation can be classified as follows :
a. roadways or highways
b. railways
c. water ways
d. airways
The science which covers designing, maintenance and operation of
the roads, for convenience of the road traffic, is called highway
engineering. The science dealing with planning, designing, operation and
maintenance of railway track, wagons, coaches, locomotives, is called
railway engineering.
3
Seeing birds flying, man must
have thought of flying and that may
probably be the starting point of
modern aeronautics. Similarly, seeing
fishes cruising in the sea or river, man
must have thought of rowing in water,
and that may probably be a starting
point in the development of water ways
and designing of ships and boats.
Introduction of Highway Highway Engineering C3010 / UNIT 1/
Similarly planning, designing, operation, control and maintenance
of water ways, airways and their connected machinery are respectively
called harbour engineering and airport engineering.
Besides the above stated four major modes of transportation, fluids
are mainly transported through pipes. Belt conveyors, cable cars,
monorails are some other minor systems of transportation, but they are
used for specific purposes. Looking to the transport characteristic of each
type of transportation system, it can easily be appreciated that roads and
railways are economical and easy for internal transportation, while airways
and waterways are main economical for transportation with foreign
countries. Airways are gaining importance even in internal movement
these days, because they cause saving in time of travel.
4
Introduction of Highway Highway Engineering C3010 / UNIT 1/
1.0.2 Road transport characteristics
While going to railway station, harbour or airport, roads is the first
mode which is going to lead you to these places. Hence it can be said that
out of all types of transport systems, road is the nearest to the man.
Characteristics of road transport are given as follows :
a. Roads can be used by all sorts of vehicles like bullock
carts, carriages, bicycles, scooters, cars, buses and
lorries, etc. They are equally useful for pedestrians also.
b. Roads can lead to any remote place.
c. Investment on road transport by government is
comparatively small. Maintenance of roads is also
cheaper than rail-track, docks, harbours and airports.
d. There is complete freedom to road users to transfer the
vehicles from one lane to another, or from one road to
another according to the requirements.
e. Local communication among villages, villages and towns
is only possible through roads.
f. Movements on roads are not time bound, as in case of
railways or airways.
g. Road transport is the only mode of transport that offers
itself for the service of whole community alike.
5
Introduction of Highway Highway Engineering C3010 / UNIT 1/
1.1 HISTORY OF HIGHWAY ENGINEERING
Traces of early roads have been found since the recorded history of the
man kind. The first and oldest mode of travel obviously was foot path. Before
invention of wheel, people used to move on foot, thus creating foot paths. Men
and material must have been transported either on backs of men or animals.
The historical road development can be divided in to the following era :
Early/ Basic roads
Roman roads
Modern roads
1.1.1 Early roads
After invention of wheel, animal drawn bullock carts continued to be
the popular mode of transport for quite a long time. This necessitated in
providing hard surface for wheeled carts. The first hard surface was
discovered in Mesopotamia at about 3500 B.C. Archeological findings
street were paved in Mohanjodaro at about 3500 B.C.
There are signs of pucca roads were used during the construction
of Illahun pyramids in Egypt between 3000 - 2500 B.C. This would be due
to the transportation of huge limestone blocks.
1.1.2 Roman roads
In the ancient Rome era, more intensive system of roads was
developed. The road radiating in many directions from Rome. Some of
6
Introduction of Highway Highway Engineering C3010 / UNIT 1/
those roads are said to be a very elaborate construction. Many of the
Roman roads are still in existence even after 2000 years. Romans were
considered to be the pioneers in road construction. With the fall of Roman
Empire, the road building technique became a lost art.
1.1.3 Modern roads
In eighteenth century, improved construction methods for roads
again began to develop. Mr. Pierre Tresaquet developed an improved
method of construction in 1764 in France. At the time when Mr. Pierre
Tresaquet was busy in developing his road construction method, Mr. John
Metcalf was engaged in his development in England. Metcalf constructed
about 290 Km road in northern region of England. Since Metcalf was blind,
his work was not recorded and thus got lost.
Telford and Macadam were the pioneers in road development in
England. Telford believed in using heavy foundation stones over the soil
sub-grade, while Macadam advocated the use of compacted crushed
aggregate layer at the bottom. Macadam’s method of road construction is
still in used and is named after his name.
1.2 CHARACTERISTIC OF SOME IMPORTANT EARLY ROADS
Important early roads include:
a. Roman roads construction
b. Tresequet roads construction
c. Metcalf’s roads construction
d. Telford’s roads construction
e. Macadam roads construction
7
Introduction of Highway Highway Engineering C3010 / UNIT 1/
1.2.1 Roman roads
Roman’s developed very elaborate system of roads mainly for the
purpose of military movement. They constructed in all about one lakh
kilometers of road, extending in whole of their empire. An Important road
constructed by Romans in 312 B.C called Appian way is still in existence
in Rome.
The main characteristics of Roman roads were as follows:
1. They weary very thick. Total thickness of the road varied
from about 0.7 m to as much as 1.2 m.
2. They were straight, without any regard for gradient. Probable
reason for straightness may be their main use for army.
3. Roads were not built on soft soil formations but on hard
stratum reached after excavation.
Method of construction for Roman roads
First of all loose soil was used to be removed from the site of the
road and a trench, equal to width of carriage way excavated to depth so
that hard stratum is reached. At the bottom of the trench one or two layers
of large stones were laid in lime mortar. The thickness of this foundation
layer ranged from 10 – 20 cm. Over this, 25 – 40 cm thick layer of lime
concrete with large size broken stone aggregate was laid. Another layer
again 25 to 40 cm of lime concrete but using comparatively small size
broken stone aggregate was laid over the previously laid layer. Lastly 10
to 15 cm thick dressed large stone blocks, set in lime mortar were used as
wearing course. Seeing thickness of the road, it is obvious that these
roads must be very strong, but they cannot prove economical, when
compared with modern design methods.
8
Introduction of Highway Highway Engineering C3010 / UNIT 1/
1.2.2 Tresaquet’s roads
Mr. Pierre Tresaquet was inspector general of roads in France from
1775 to 1785. He developed an improved method of road construction.
The main feature of his work was that the thickness of the road was about
30 cm. He also made consideration of sub-grade moisture and drainage
from the surface. He also emphasized the need for continuous
maintenance of road to keep it in good shape. At the time of Napoleon,
quite elaborate road system was developed in France mainly for use of
military adventures.
Method of construction for Tresaquet’s roads
On the prepared sub-grade a layer of large foundation stones was
laid, keeping all the stones on edge. At the edges of the road, a large size
stone was laid length wise to give lateral support to the foundation layer.
The interstices of the foundation stone layer were filled with stone
aggregate of smaller size. Compacted thickness of this layer was about 8
cm. Lastly the top wearing course was laid of walnut sized stones and
compacted to a thickness of about 5 cm. A cross slope of about 1 in 45
was used to be developed in the road surfaced by adjusting thickness
mainly in top and intermediate layers. Lastly, shoulders were also given
suitable cross slope, away from the edges of carriage way.
9
Introduction of Highway Highway Engineering C3010 / UNIT 1/
1.2.4 John Metcalf roads (1717-1810)
He was working in England at the time when Tresaquet was busy in
France. He experimented road construction with a graded mixture of earth
and gravel. Since Mr. Metcalf was blind, his work could not be recorded.
But it is believed that he was following the procedure outlined by Robert
Philips in 1737. Robert Philips method consisted of laying gravel layer
upon a well drained and dried sub-grade. Gravel layer was used to be
compacted in due course of time, by the action of the traffic using road.
Metcalf constructed about 290 Km of road in northern parts of England.
Telford roads (1757-1834)
Thomas Telford was Scottish road engineer and founder of the
institution of civil engineers. He used big size stones in foundation wearing
from 17 – 22 cm to develop a firm base. He also provided cross drains
under foundation layer to keep the sub-grade in dry condition. He
proposed provision of cross drains at intervals of about 90 m. Total
thickness of road advocated by him was about 38 cm.
Construction Method for Telford roads
A level sub-grade which may be on embankment or cutting was
prepared in the required width. Telford adopted 9 mm width of the road.
On the prepared sub-grade a layer of large size stone boulders, varying in
size from 17 cm near the edges to a maximum size of about 22 cm at the
centre of the width of the road was laid. Laying of the stones was done by
packing. By using smaller size stone near the edges and larger size near
centre, a cross slope, of 1 in 45 in road surface was developed. The
interstices in this boulder foundation layer were filled with smaller stones
and chippings and properly compacted.
10
Introduction of Highway Highway Engineering C3010 / UNIT 1/
Now central width of about 5.5 m ( 18’ ) of road was covered with
intermediate coating consisting of two layers. The compacted thickness of
first layer was about 10 cm and consisted of 6.5 cm size stone aggregate.
The compacted thickness of second layer was about 5 cm and consisted
of about 4 cm size stone. These layers were used to be rammed initially,
but allowed to be compacted under traffic. No water was sprinkled during
compaction. Only rain water was used to help compaction and
consolidation of these layers.
Over the intermediate coat, 4 cm thick gravel layer was used to act
as blinding and wearing layer. The finished surface used to have a cross
slope of 1 in 45. The remaining width of the foundation left untreated by
intermediate coats (two layers), on either side, was treated by lime
concrete. Lime was mixed with broken stone aggregate about 10-15 cm
size to prepare lime concrete, to be laid on either side of the road. This
treatment provided lateral stability to the road structure.
1.2.5 Macadam Roads ( 1756-1838 )
He, for the first time put forward entirely new concept of road
construction in 1827. He was a Scottish engineer and was surveyor
general of roads in England. Important characteristic of his concept are as
follows:
It was he who for the first time recognized the importance of sub-
grade compaction and drainage. To affect speedy surface drainage
he recommended suitable cross slope for the sub-grade.
It was he who realized for the first time that heavy foundation
stones are not at all necessary. If sub-grade is prepared properly
and kept well drained it can be very well bear the traffic load
transmitted to it through foundation layer, having smaller
11
Introduction of Highway Highway Engineering C3010 / UNIT 1/
compacted thickness of small size broken stones. He was of the
opinion that a broken stone layer of few centimeter thickness can
sustain mush heavier load than a thick layer of big size stones.
Size of the aggregate to be used in wearing course was decided
according to requirements of stability under the effect of vehicles.
Method of Construction for Macadam roads
Sub-grade was prepared and compacted to the required
width of the road. Prepared sub-grade was given the same camber,
as to given to the finished road surface. Construction of road
according to Macadam method consists of three layers, namely,
foundation layer, intermediate layer and wearing surface layer.
Foundation layer was 10 cm thick (compacted) and was made from
5 cm size aggregate. Intermediate layer was also 10 cm thick
(compacted) but made from aggregate passing 40 mm sieve.
Lastly, wearing surface was made 5 cm thick (compacted) using
aggregate passing 20 mm sieve. Cross slope of finished surface
was kept as 1 in 36.
In those days, there were no rollers to affect thorough
compaction and interlocking, and hence, this action was used to be
achieved by means of traffic. This was the reason that next layer
could not only be laid once the previously laid layer gets thoroughly
compacted. Macadam method was first scientific method based on
modern concepts and hence is still in use in most parts of the
world, though with certain modifications.
12
Introduction of Highway Highway Engineering C3010 / UNIT 1/
1.3 Comparison Between Macadam and Telford Roads
a. Telford roads are costlier than Macadam roads.
b. In the case of Telford construction, sub-grade was kept horizontal due
to which drainage of sub-grade was not proper. In the case of
Macadam construction sub-grade was given 1 in 36 cross slope. This
aspect helped in better sub-grade drainage.
c. Large size stones were adopted by Telford for foundation. Size of
stone varied from 17 cm near edges to 22 cm at the centre of the road.
In the case of Macadam roads 5 cm was the maximum size of the
aggregate used for foundation layer.
d. Cross slope in Telford using smaller size stones at the edges and large
size stones at the centre of the width-developed roads. Thicknesses of
subsequent intermediate and surfacing layers, is kept constant for the
full width of the road. In Macadam roads, required camber was given to
the sub-grade itself and all the subsequent layers of aggregate
including foundation layer of uniform thickness for the whole of the
width of the road.
e. Telford construction is carried out in four layers namely foundation
layer, two layers of intermediate coat and 4 cm thick wearing top layer.
Macadam construction is done in three layers. Two layers each of 13
cm compacted thickness as foundation layers and 5 cm thick surfacing
layer.
f. In Telford roads, camber given was 1 in 45 while in Macadam it was 1
in 36.
g. Telford’s foundation layer, being of larger sized stones, behaved like
semi flexible road but Macadam’s base was yielding type and hence
Macadam roads behaved like fully flexible roads.
h. Total thickness of road structure was about 40 cm in case of Telford
but only about 25 cm in case of Macadam.
13
Introduction of Highway Highway Engineering C3010 / UNIT 1/
TEST YOUR UNDERSTANDING BEFORE YOU CONTINUE WITH THE NEXT
INPUT….!
1. Describe briefly the contribution of Tresaquet , Metcalf, Telford and
Macadam to road improvement of a scientific nature.
2. Write short notes on the history of:
a. Early basic roads
b. Romans roads
c. Moderns roads
3. Discuss the comparative specifications of Telford and Macadam road
crust construction.
14
ACTIVITY 1
GOOD LUCK….
Introduction of Highway Highway Engineering C3010 / UNIT 1/
1. Pioneers contributions are :
a. Tresaquet
Developed an improvement method of road construction
which feature of his work was that the thickness of the road
was about 30 cm.
The interstices of the foundation stone layer were filled with
stone aggregate of smaller size and compacted thickness
of this layer was about 8 cm.
Top wearing course was laid of walnut sized stones and
compacted to a thickness of about 5 cm.
A cross slope of about 1 in 45 was used to be developed in
the road surfaced by adjusting thickness mainly in top and
intermediate layers.
b. Metcalf
Experimented road construction with a graded mixture of
earth and gravel.
Method consisted of laying gravel upon a well drained and
dried sub-grade. It used to be compacted in due course of
time, by the action of the traffic using road.
15
FEEDBACK ON ACTIVITY 1
Introduction of Highway Highway Engineering C3010 / UNIT 1/
c. Telford
Used big sized stones in foundation wearing from 17-22 cm
to develop a firm base
Provided cross drains under foundation layer to keep the
sub-grade in dry condition
Level sub-grade on embankment or cutting was prepared in
the required width.
d. Macadam
Using entirely new concept of road construction.
Recognized the importance of sub-grade compaction and
drainage
Using a broken stone layer of few centimeter thickness can
sustain much heavier load than a thick layer of big size
stones
Size of the aggregate to be used in wearing course was
decided according to requirements of stability under the
effect of vehicles.
2.
a. Early roads.
After invention of wheel, animal drawn bullock carts continued to be
popular mode of transport for quite a long time. This necessitated
providing hard surface for wheeled carts. The first hard surface was
discovered in Mesopotamia at about 3500 B.C. Archeological
findings in Mohanjodaro indicate that about 3500 B.C Street was
paved.
16
Introduction of Highway Highway Engineering C3010 / UNIT 1/
b. Romans roads.
In the ancient Rome era, more intensive system of roads was
developed. The roads radiating in many directions from Rome.
Some of those roads are said to be a very elaborate construction.
Many of the Roman roads are still in existence even after 2000
years. Romans were considered to be the pioneers in road
construction. With the fall of Roman Empire, the road building
technique became a lost art.
c. Modern roads.
In eighteenth century, improved construction methods for roads
again began to develop. Mr. Pierre Tresaquet developed an
improved method of construction in 1764 in France. At the time
when Mr. Pierre Tresaquet was busy in developing his road
construction method, Mr. John Metcalf was engaged in his
development in England. Metcalf constructed about 290 Km road in
northern region of England. Telford and Macadam were the
pioneers in road development in England. Telford believed in using
heavy foundation stones over the soil sub-grade, while Macadam
advocated the use of compacted crushed aggregate layer at the
bottom. Macadam’s method of road construction is still in use and
is named after his name.
3. Comparison between Telford roads and Macadams roads are :
a. Telford roads are costlier than Macadam roads.
b. In the case of Telford construction, sub-grade was kept horizontal
due to which drainage of sub-grade was not proper. In the case of
Macadam construction sub-grade was given 1 in 36 cross slope.
This aspect helped in better sub-grade drainage.
c. Large size stones were adopted by Telford for foundation. Size of
stone varied from 17 cm near edges to 22 cm at the centre of the
17
Introduction of Highway Highway Engineering C3010 / UNIT 1/
road. In the case of Macadam roads 5 cm was the maximum size of
the aggregate used for foundation layer.
d. Cross slope in Telford roads was developed by using smaller size
stones at the edges and large size stones at the centre of the width.
Thicknesses of subsequent intermediate and surfacing layers, is
kept constant for the full width of the road. In Macadam roads,
required camber was given to the sub-grade itself and all the
subsequent layers of aggregate including foundation layer of
uniform thickness for the whole of the width of the road.
e. Telford construction is carried out in four layers namely foundation
layer, two layers of intermediate coat and 4 cm thick wearing top
layer. Macadam construction is done in three layers. Two layers
each of 13 cm compacted thickness as foundation layers and 5 cm
thick surfacing layer.
f. In Telford roads, camber given was 1 in 45 while in Macadam it
was 1 in 36.
g. Telford’s foundation layer, being of larger sized stones, behaved
like semi flexible road but Macadam’s base was yielding type and
hence Macadam roads behaved like fully flexible roads.
h. Total thickness of road structure was about 40 cm in case of
Telford but only about 25 cm in case of Macadam.
18
Introduction of Highway Highway Engineering C3010 / UNIT 1/
1. Describe brie the characteristic of road transport..
2. Describe the method of construction for Macadam roads.
3. Classify the modes of transportation used in Malaysia.
19
Question
Introduction of Highway Highway Engineering C3010 / UNIT 1/
1. The characteristics of road transport are as follows :
i. Roads can be used by all sorts of vehicles like bullock carts,
carriages, bicycles, scooters, cars, buses and lorries, etc.
They are equally useful for pedestrians also.
ii. Roads can lead to any remote place.
iii. Investment on road transport by government is
comparatively small. Maintenance of roads is also cheaper
than rail-track, docks, harbors and airports.
iv. There is complete freedom to road users to transfer the
vehicles from one lane to another, or from one road to
another according to the requirements.
v. Local communication among villages, villages and towns is
only possible through roads.
vi. Movements on roads are not time bound, as in case of
railways or airways.
vii. Road transport is the only mode of transport that offers itself
for the service of whole community alike.
2. Method of Construction for Macadam roads
20
Answer
Introduction of Highway Highway Engineering C3010 / UNIT 1/
Sub-grade was prepared and compacted to the required
width of the road. Prepared sub-grade was given the same camber,
as to given to the finished road surface. Construction of road
according to Macadam method consists of three layers, namely,
foundation layer, intermediate layer and wearing surface layer.
Foundation layer was 10 cm thick (compacted) and was made from
5 cm size aggregate. Intermediate layer was also 10 cm thick
(compacted) but made from aggregate passing 40 mm sieve.
Lastly, wearing surface was made 5 cm thick (compacted) using
aggregate passing 20 mm sieve. Cross slope of finished surface
was kept as 1 in 36.
In those days, there were no rollers to affect thorough
compaction and interlocking, and hence, this action was used to be
achieved by means of traffic. This was the reason that next layer
could not only be laid once the previously laid layer gets thoroughly
compacted. Macadam method was first scientific method based on
modern concepts and hence is still in use in most parts of the
world, though with certain modifications.
3. Modes of transportation can be classified as follows:
a. roadways or highways
b. railways
c. water ways
d. airways
21