INTRODUCTION_TO_TRANSPORTATION_ENGINEERI.pdf

1
INTRODUCTION TO
TRANSPORTATION ENGINEERING
DEPARTMENT OF CIVIL ENGINEERING
PRESENTED BY:
PROF. SHRADHESH R. MARVE

Transportation Engineering
 Transportation engineering is a sub-discipline of civil engineering
which deals with the application of technology and scientific
principles to the planning, functional design, operation and
management of facilities for any mode of transportation in order
to provide the safe, rapid, comfortable, convenient, economical,
and environmentally compatible movement of people and goods
(transport).
 The planning aspects of transport engineering relate to urban
planning, and involve technical forecasting decisions and political
factors.
 Transportation engineering, as practiced by civil engineers,
primarily involves planning, design, construction, maintenance,
and operation of transportation facilities

2

Highway Engineering
 Highway engineering is an engineering discipline which involves
the design, construction and maintenance of Highway Roads &
Systems, urban streets as well as parking facilities. Important
aspects of highway engineering include overall planning of routes,
financing, environmental impact evaluation, and value engineering
to compare alternatives.
3

Traffic Engineering
 Traffic engineering involves planning for the volumes of traffic to
be handled, the methods to accommodate these flows, the lighting
and signing of highways, and general layout.
 Older techniques include signs, signals, markings, and tolling.
 Newer technologies involve intelligent transportation systems,
including advanced traveler information systems (such as variable
message signs), advanced traffic control systems (such as ramp
meters), and vehicle infrastructure integration.
4

5
Transport Network
MEANS OF TRANSPORT
LAND WATER AIR
ROADWAYS RAILWAYS PIPELINES
INLAND
WAYS
OVERSEAS
WAYS
DOMESTIC
AIRWAYS
INTERNATIONAL
AIRWAYS
PUBLIC
UNDERTAKING
PRIVATE
AIRLINES

Role of Transportation
6
 Transport and economic growth
 Place utility of goods
 Time utility of goods
 Producer and consumer
 Preservation of quality of goods
 Mass production
 Exploitation of natural resources
 Transport and urbanization
 Transport and industrial development

Role of Transportation…
7
 Transport and agricultural development
 Costs of goods
 Administration
 Defence and strategic needs
 Tourism
 Transport facilities and social activities

Highway Transportation
Engineering
 Definition
The application of technology and scientific principles to the planning,
functional design, operation, and management of roads, streets and highways,
their networks, terminals, abutting lands, and relationships with other modes of
transportation.
 Areas of highway transportation engineering:
 Planning of streets and highways
 Geometric design of road facilities
 Traffic operations and control
 Traffic safety
 Maintenance of road facilities and controls
8

History of Road Construction
 Roman Road Construction
Basic cross section
9

History of Road Development in
India
 Ancient Period (3500 BC)
 Mughul Period (15th Century)
 British Period (17th & 18th Century)
 Post Independence (1947 onwards)
10

Highway Components Cross-section
11

Modes of Transport
12
 Railways
 Surface
 Underground
 Light rail transit (LRT)
 Road Transport
 Air Transport
 Water Transport
 Pipelines

Transport Modes Characteristics
13
 Speed
 Safety
 Adequacy
 Frequency
 Regularity
 Integration
 Responsibility
 Cost
 Cheapness
 Fuel efficiency

Transport modes in India
14
 Railways :
 62500 km, Passengers- (20% of total traffic)
 Freight traffic- (40% of total traffic)
 Road Transport
 3 million km
 National Highways: 66900 km
 Total vehicles- 67 million and growth rate of 10%

Transport modes in India…
15
 Air India and Indian airlines, other private airlines
 7.1 million passengers (2004-2005)
 Domestic air traffic increasing 10% per anum
 Indian coast-line: 5660 km, 176 ports – 10 major
ports and 23 intermidiate

Advantages and Disadvantages of
Road Transport
16
 Wide geographical coverage provided by
roads
 Low capital investments
 Quick and assured deliveries
 Flexibility
 Door-to-door service
 Simpler packaging
 Personalized service
 Personalized travel

Advantages and Disadvantages of
Road Transport….
17
 Safety
 Environmental pollution
 Parking problem
 Long-hauls
 Energy

Role of Roads in Indian Economy
18
 Connection to villages
 Communications in hilly terrain
 Strategic importance
 Carriers of fright and passengers as a feeder to other
modes
 Helps agriculture, dairy, forest, fisheries, tourism, etc.
development
 Employment
 Famine and flood relief
 Administrative convenience

Research Areas in transportation
Engineering
19
 Traffic engineering and management
 Transportation planning and management
 Road safety
 Transportation economics
 Urban mass transit planning, management and
operation
 Pavement materials characterization
 Pavement management systems
 Pavement design and analysis

History of Growth of Highways
 Differences – Highways, Roads, Streets and
Expressways
 Ancient man age and usage of animal drawn
vehicles
 Invention of the wheel, steam engine, etc.
 The Roman Civilization
 The Persians and Chinese Civilizations
 Indus Valley Civilization
 The Mauryas, the Guptas and the mughals.
20

Cross Section of Early Roads
21
Telford Pavement
Macadam Pavement

Development of Roads in India
during British Period
22
 Neglect of the road system in India
 Military and administrative purpose only
 Introduction of railways
 Feeder roads to the railways
 Jayakar Committee (1927)
 Landmark in the planned development of roads
 Central road fund as road development fund
 The Indian Roads Congress (1934)
 Produced standards and codes of practices for the
planning, design, operation and management of
roads

Development of Roads in India
23
 Road Development Plans
 Nagpur Plan ( 1943-1961)
 Twenty year road development plan
(Bombay Plan) 1961-1981
 Twenty year road development plan
(Lucknow Plan) 1981-2001
 Road Development Plan, Vision 2021

Rural Roads, Vision 2025
24
 Indian Roads Congress drafted
 Building of core road network which gives
accessibility to each village
 Habitations with a population above 100 should be
connected by all whether roads
 It is estimated that the length o 2,90,000 km of new
roads will be needed to achieve the full connectivity
(outlay for this 26,000 c, besides 66,000 c already)
 Up gradation of 1,237,000 km length (1,64,000 c)
 Maintenance of Rural Road Network (7,500 c/
anum)

Roads in the World Today
25
 USA has the largest network of roads (6.3 M-km)
 India with its 3.3 M-km road network comes second
 Density of roads (km/sq km) is very high in Germany
and Japan which are small in area
 India : 1 km/sq km, USA: 0.67 and China : 0.12 km/sq
km
 Percentage of paved roads
 UK : 100%
 Germany : 99%
 USA : 91%
 India : 50%

International Comparison of
Expressways
26
 USA – 88400 km
 Germany- 11000 km
 Japan – 8500 km
 China – 6000 km
 UK – 4000 km
 Malaysia – 1500 km
 India – 200 km

Functional Classification of Roads
27
 Administration of the roads
 Appropriate design standards
 Developing appropriate and integrated network
 Broad Classification:
 Urban roads
 Rural roads

Classification of Urban Roads in India
28
 Expressways
 Arterial Streets
 Sub-arterial streets
 Collector streets
 Local Streets

Classification of non-urban roads in India
29
 Primary system
 Expressways
 National Highways
 Secondary System
 State highways
 Major district roads
 Tertiary System
 Other District Roads
 Village Roads

Administration of Roads
30
 Administration of National Highways
 Ministry of defense
 Ministry of railways
 The border road development board
 The ministry of rural development
 Ministry of Road Transport and Highways
(MoRTH)
 National Highways Authority of India
 Central Road Fund (CRF)
 Administration of State Roads

Road Research
31
 Central Road Research Institute
 State Highway Research Laboratories
 Highway Research Station, chennai
 Maharashtra Engineering Research Institute, Nashik
 Gujarat Engineering Research Institute,Vadodara
 Highway StaffTraining Institute
 National Institute for training of highway engineers, NOIDA
 IITs, NITs or institutions like BITS

National Rural Road Development
Agency
32
 NRRDA
 Pradhan Mantri Gram Sadak Yojna (PMGSY)
 Connect every habitation with a population 1000
persons through good all weather roads (2003)
 Connect every habitation with a population 500
persons through good all weather roads (2007)
 Now it is habitations with population 100
 60000 c and connectivity to about 1,00000
habitations

Types of Transportation Plans
33
 National Plan
 National Transport Plan
 Regional Transport Plan (State or Region)
 Local Transport Plan (District, city or town)
 National Transport Policy Committee

Highway Financing and Taxation in
India
34
 Construction and maintenance of highways, roads and streets by
the government
 Taxes, Levies and tolls
 Level of taxation on roads and road transport in India is very high
as compared to its outlay
Year Tax Revenue
(C)
Expenditure
on Roads (C)
Expenditure
on roads as %
1950-51 47.37 34.47 72.7
1960-61 166.94 109.76 65.7
1970-71 683.12 257.60 37.7
1984-85 4400.00 1824.00 41.5
2001-02 5000.00 2100.00 42.0

Phasing and Road development in
India
 Phasing : Road in ancient India, Roads in Mughal period, Roads in 19th
centaury have been explained in earlier lectures.
Development of road in following stages:
 Jayakar committee report -1928
 C.R.F - 1929
 I.R.C - 1934
 C.R.R.I - 1950
 Motor vehicle act - 1939
 Nagpur road conference - 1943 -1963 -------1st 20 yr. plan
 National Highway Act - 1956
 Highway research board - 1973.
35

2nd 20 year plan - 1961-1981 finalized in 1959 –IRC also Called as Bombay Road
Plan.
3rd 20 year plan - 1981-2001.
Development after 1947:
 By 1947 when India got independence – 3,88,226 km length of Roads with
surface roads -36.80% (1,42,882 km)-– 3,97,600 km by 1950-51- Density of
11.80km/100 km2 by 1951-15,02,700 km by 1980-81.
 Density of 21.00 km/100 km2 by 1961, 34 by 1972 & 46 by 1981, Rapid
increase in transportation-three lakh vehicles to 44 lakh from 1951-1981.
 Freight traffic from 5.50 to over 104 billion t-km. passenger traffic from 23 to
over 31.50 billion passenger-km during above 30 years due to national income,
population, agricultural and industrial products.
 Tax by road transport increased from 61 Cr to 2,388 Cr.
36

 2nd 20 year plan - 1961-1981 finalized in 1959 –Initiated by IRC also Called as
Bombay Road Plan.
 Consideration for the development of road – double than Nagpur road plan –
10,57,330 km or 32 km /100 km2 area. An out lay of Rs 5,200 Cr for the period
ending 1980-81 based on 1958 price level. Con. Of 1,600 km express ways was
also included.
 3rd five year plan – 1961-66, Annual plan 1966-69 & Development of Roads –
steady pace.
 4th Five plan 1969 – 1974
 Total road length by the end of 1974 – 11,45000 km (All categories)
 Density- 34.80 > 2nd 20 year plan 1961-1981.
 5th five year plan 1974-1979 Annual plan 1978-80 Preparation of 3rd long term
 Road development. Plan got delayed.
 6th five year plan 1980-185
37

Twenty Years Road Development
Plans

Nagpur road congress 1943
 A twenty year development program for the period
(1943-1963) was finalized.
 It was the first attempt to prepare a coordinated road
development program in a planned manner.
 The roads were divided into four classes
 The committee planned to construct 2 lakh kms of road
across the country within 20 years.
 They recommended the construction of star and grid
pattern of roads throughout the country.
 One of the objective was that the road length should be
increased so as to give a road density of 16 kms per 100
sq.km
39

Salient features
i) The responsibility of construction and maintenance of national
highways were assigned to the central government.
ii) Planned for 20 year (1943-63) aiming to provide 2 lakh km of surfaced
roads and remaining un surfaced roads. Total targeted road length
5,32,700 km .Achieved 7, 09,122km by the end of 1961.(road density
16km/100sqkm).
iii) The road length formulated is based on star and grid pattern. But due
consideration was given for existing irregular pattern and obligatory
points not fitting in the geometric pattern.
iv) The size of grid is 16km so that max distance from the centre is 8km
and average distance from village road to metalled road is 3.2 km.
v) The ODR and VR are meant to provide internal road system linking to
Higher category of road network.
vi) An allowance of 15 % was given for agricultural and industrial
development during next 20 years.
vii) The length of railway tracks in the area was also considered in
deciding the length of the first category of road.
40

Star and Grid Formulae
41
 The total length of the first category or mettalled roads for NH, SH
and MDR in km is given by the formula as follows:
Where,
Where,
A is agricultural area sqkm
B is non agricultural area sqkm
N number of towns and villages with population range 2001-5000
T number of towns and villages with population over 5000
D development allowance of 15 % of road length for next 20 years
R is existing length of railway track , km
R
D
T
N
B
A
km
MDR
SH
NH −
+
+
+
+
=
+
+ ]
8
6
.
1
32
8
[
)
(

Star and Grid Formulae…
42
 The total length of secondary category of roads (km)
 ODR + VR (km) = [0.32V+0.8Q+1.6P+3.2S] + D
Where,
V is number of villages with population 500 or less
Q number of villages with population range 501-1000
P number of villages with population range 1001 -2000
S number of villages with population range 2001 -5000
D development allowance of 15% for next 20 years

Example
43
 The following data were collected for planning the road development program of
a backward district.
1. Total Area = 9600 sq km
2. Agricultural and developed area = 3200
3. Existing railway track length = 105 km
4. Existing length of mettalled road = 322 km
5. Existing length of unmettalled road = 450 km
6. Number of towns and villages in different population ranges are :
7. Calculate the additional lengths as per Nagpur road plan formulae for district.
Population >5000 2001-
5000
1001-
2000
501-1000 <500
Number of villages
& towns
8 40 130 280 590

Solution:
1)Total length of metalled road length by NRP is obtained from:
(A/8+B/32+1.6N+8T ) +D-R
HereA=3200 km2 : B=9600-3200 = 6400 km2 N= 40,T=8,
D=15 %, R=105
Metalled Rd “L” = 3200/8+6400/32+1.6x40+8x8)+15% of (322+450) – 105
=732.20 km
Additional metalled length = 732.20 – 322 = 410.20 km
Unmetalled Road length = (0.32V+0.8Q+1.6P+3.2 S) + D
= (0.32 x 590 +0.80 x 280 + 1.6 x 130 +3.20 x 40) – 15% x (322+450)
= 861 km
Additional un metalled road length needed = 861 – 450 = 411 km
44

Bombay road congress 1961
 This plan envisaged overall road length of 10,57,330 km by the year
1981 (achieved .
 The cost of the plan has been worked out to Rs. 5,200 crores based on
1958 price level.
 Five different formulae were framed to calculate the length of NH, SH,
MDR, ODR and VR.
Classification of the Roads by Bombay Road Plan:
i) Express way: are those connecting major capitals and other important
centre with in the country where the traffic density is high and the vehicles
are allowed to travel with no cross interruption. The express way are
constructed with high design standards and design speed.
ii) NH, SH, MDR, ODR & VR.
45

Bombay road congress 1961
 It was the second 20 year road plan (1961-1981)
 The total road length targeted to construct was about 10
lakhs.
 Rural roads were given specific attention. Scientific
methods of construction was proposed for the rural roads.
 The necessary technical advice to the Panchayaths should
be given by State PWD's.
 They suggested that the length of the road should be
increased so as to give a road density of 32kms/100 sq.km
 The construction of 1600 km of expressways was also
then included in the plan.
46

Salient features
1. Drawn on more scientifically in view of development needed in
underdeveloped areas. Targeted road density 32km per 100 sqm, road
length of10,57,330 km, achieved road length = 15,02,697km.
2. Maximum distance of any place in a developed or agricultural area
would be6.4 km from a metalled road and 2.4 km from any category of
roads.
3. Every town with population above 2000 in plains and above 1000 in
semi-hill areas and above 500 in hilly areas should be connected by a
metalled road.
4. While calculating the road length in hilly regions, an allowance upto
100percent to be made in arriving at the road length.
5. Expressways have also been considered in this plan and 1600 km of
length has been included in the proposed target of National Highways.
6. Length of railway track is considered independent of the road system.
7. The development factor of only 5 % is provided for future development
and unforeseen factors.
47

Formulae
48
D
R
Q
P
N
M
k
C
B
A
km
MDR
SH
NH +
+
+
+
+
+
+






+
+
=
+
+ ]
4
.
2
4
.
6
6
.
9
2
.
11
24
48
[
24
16
8
)
(
D
M
K
C
B
A
km
NH +
+
+
+
+
= ]
8
32
[
]
96
80
64
[
)
(
D
P
N
M
k
C
B
A
km
SH
NH +
+
+
+
+






+
+
=
+ ]
6
.
1
2
.
11
24
48
[
32
24
20
)
(
D
T
S
R
Q
P
N
M
k
C
B
A
km
ODR
MDR
SH
NH +
+
+
+
+
+
+
+
+






+
+
=
+
+
+ ]
32
.
0
8
.
0
4
8
.
12
6
.
9
2
.
11
24
48
[
16
32
3
16
3
)
(
D
V
T
S
R
Q
P
N
M
k
C
B
A
km
VR
ODR
MDR
SH
NH +
+
+
+
+
+
+
+
+
+






+
+
=
+
+
+
+ ]
2
.
0
64
.
0
6
.
1
9
.
5
8
.
12
6
.
9
2
.
11
24
48
[
12
8
4
)
(

Formulae…
49
Where,
A is agricultural area sqkm
B is semi developed area sqkm
C is undeveloped area sqkm
K is number of towns with population over 1,00,000
M is number of towns with population range 1,00,000-50,000
N is number of towns with population range 50,000-20,000
P is number of towns with population range 20,000-10,000
Q is number of towns with population range 10,000-5,000
R is number of towns with population range 5,000-2,000
S is number of towns with population range 2,000-1,000
T is number of towns with population range 1,000-500
V number of towns with range below 500
D development allowance of 5 % of road length for next 20 years


Example
50
 Calculate the total lengths of NH, SH, MDR, ODR and VR needed in a district as per second
20-year plan . The data collected is as follows:
 Total area =18400 sq km
 Developed and agricultural area = 8000 sqkm
 Undeveloped area = 4800 Sq km
 Population distribution
Population range Number of towns
<500 200
500-1000 350
1000-2000 750
2000-5000 360
5000-10000 150
10000-20000 80
20000-50000 25
50000-100000 10
>1,00000 5

Lucknow road congress 1984
 This was the third 20 year road plan (1981-2001). It is also called
Lucknow road plan.
 It aimed at constructing a road length of 12 lakh kilometres by the
year 1981 resulting in a road density of 82kms/100 sq.km
 The plan has set the target length of NH to be completed by the
end of seventh, eighth and ninth five year plan periods.
 It aims at improving the transportation facilities in villages, towns
etc. such that no part of country is farther than 50 km from NH.
 One of the goals contained in the plan was that expressways
should be constructed on major traffic corridors to provide speedy
travel.
 Energy conservation, environmental quality of roads and road
safety measures were also given due importance in this plan.
51

Basis of the Formulae
52
 Primary Road System
 Expressway – 2000 km : Based on some project formulation
 National Highways: concept of 100 km Square grids
 Length of the NH in country, km = 3287782/50 = 65,756 km
 Secondary System: length of SH
 NH and SH should pass through every town and urban area: 3364 towns in
the country (Based on census data: 1981)
 Area of each square grid = 3287782/3364 = 977.3 Sq km (31.26 km each
side)
 Total SH +NH = 2*31.26* 3364 = 2,10,250 km
 SH length = 2,10,250 km – 66000 km = 1,45,000 km.
 By Total Area, SH , Length (km) = Area of the state/ 25 (Double of NH)
 By total number of towns: {(62.5 * no of towns in the state) – (Area of state/
50)}

Length of MDR, ODR and VR
53
 Major District Roads
 Total length of MDR in the country = 3,00,000 km
 By Total Area, MDR , Length (km) = Area of the state/ 12.5 (Double of
SH)
 By total number of towns in state : {(90*no of towns in the state)}
 Tertiary System
 Total road length for the state
 Density to be achieved per 100 sq km.
 The area of a certain district in India is 13,400 sq km and there
were 12 towns as per 1981 census. Determine the lengths of
different categories of roads to be provided in this district by the
year 2001.

Salient features
Third twenty year road development plan 1981-2001: (Also known as Lucknow
Road Plan) : Published in 1984.
Policies and objectives:
i) Future road development shall be as per revised classification of road system –
Primary, Secondary & Tertiary.
ii) To preserve the rural oriented economy –small towns to be developed with
essential facilities – all villages population more than 500 shall be connected with
all weather roads by the end of 19th centaury.
iii) Over all density should be increased to 82%/100 km2 by 2001. 40% for hill
areas of altitude up to 2100m and 15 km /km2 for altitude above 2100m.
iv) NH should be expanded to form 100km square grid so that no part of country
is 50km away form a NH.
v) The lengths of SH and MDR should be on both areas and numbers of towns and
villages with population more than 5000.
54

Salient features
vi) Express ways to be constructed along major corridors t provide fast travel.
(Poona Mumbai E.H. and Bengaluru Mysore E.H).
vii) Towns more than 5000 population should be connected by MDR and villages
with population 1000 to 1500 by ODR. There should be a road within a distance
of 3km in plains and 5.0km in hilly terrain connecting all villages or group of
villages with population less than 500.
viii) Roads should be built in less industrialized area to attract the growth of
industries.
ix) Long term master plans should be prepared at various levels i.e.., taluka,
district, state and national scientifically to provide maxi. Utility.
x) Existing roads to be improved for their geometry, surface condition, defects,
strengthening etc., to save vehicle operating cost and conservation of energy.
xi) There should be improvement in environmental quality and road safety.
55

Road Types and Classification
Types of Roads:
Based on serviceability:
 All weather roads:- Negotiable during all weather except at major river
crossings where interruption of traffic is permissible to a certain extent.
 Fair weather roads- traffic is interrupted under high floods at river or nala
crossings – on Low level causeways or bridges.
Based on carriage way condition:
 Paved roads : A hard surface – at least WBM.
 Unpaved: Gravel roads even not covered withWBM.
Based on surface of pavement :
 Surface roads: Covered with Bituminous or Concrete surfacing.
 Also called as B.T (Black Topped/Flexible) surface or Concrete surface (Rigid
pavements / White topped) surface roads respectively.
 Un surfaced roads: Neither covered with bitumen nor concrete surfacing.
56

Methods of Roads classification : Based on:
➢Traffic volume : Low,Medium and Heavy
➢Load transported : Arbitrarily fixed by diff. agencies. May not be
a common agreement reg. the limits for classification.
➢Location and function:More acceptable classification.
➢Based on Nagpur Plan :
National Highway (NH)- (Primary Roas System) - Running through
Breadth and Length of India-connecting foreign highways-capitalsports-
industrial and tourist centers - defense movementsuninterrupted-
road network-
NH-1: Delhi-Ambala-Amritsar
NH-1A: Jalandar – Srinagar – Uri
NH-4 (Old) Poona Bengaluru (PB)
57

➢State Highway (SH) – (Secondary road system) Arterial roads of a state
connecting up to a NH of adjacent state, district head quarters & imp cities.
 These are numbered.
➢Major District Roads (M.D.Rs) : (Secondary road system) Within the district
and connecting adjoining highways in the district – lower speed, geometric design
specifications than NH and SH.
➢Other District Roads (O.D.Rs): (Tertiary road system) Serving rural areas for
transportation of men and materials to market places –connect taluka head quarters
– block development head quarters or other main roads.
➢Village Roads : (Tertiary road system) Connecting villages or group of villages
with each other and to the nearest road of higher category.
Nagpur Road Conference was assigned reg. the economics of road con. That all
roads of any class should be constructed in such a way that maintenance and
capital costs over a period of 20 years will be minimum
58

Modified classification:
➢Primary system : Express way and NH.
➢Secondary system : SH and MDR
➢Tertiary system or rural roads : O.D.R and V.R
Further classification of Urban roads:
Arterial roads : Traffic through a continuous route.
Sub arterials roads : Lower level of traffic mobility
Collector streets: Collect traffic from local streets (Gallies)
Local streets.: Access to abutting properties – Gallies / Oni
59

Road Pattern
1. Introduction
 When the road is constructed in patterns like rectangular, radial,
hexagonal, etc for the proper management of traffic and also to
interconnect the branch roads with main roads then it is called road
pattern.
 The main principle of road patterns is to reduce the time and distance
that the vehicle takes to reach the destination place. It also focuses on
the interconnection of branch roads.
 It increases the response time of normal vehicles as well as emergency
vehicles like ambulances, fire engines, etc. to reach the destination
place.
 Road Pattern also plays a vital role in the management of traffic but it is
neglected by most countries. There are 6 types of road patterns that are
mostly used.
60

2. Types of road pattern
 1.Rectangular or Block pattern
a. In this pattern; the whole area is divided into rectangular blocks.
b. Streets or branch roads intersect with each other at the right angle.
c. The main roads always pass through the centre and it should be wide enough.
d. Branch roads may be narrow as compared to main roads.
e. The main roads should be provided with a direct approach to outside the city.
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 Advantages
 The rectangular blocks can be further fractioned into small
rectangles that may be used for the construction of buildings
placed back to back, having roads on their front.
 It is widely adopted on city roads.
 Construction and Maintenance is quite easy.
 Disadvantages
 It is not convenient because roads are perpendicular to each
other. This increases the rate of accidents due to poor visibility at
a perpendicular junction.
62

2. Radial or Star and Block Pattern
a. It is a combination of star and block patterns.
b. The entire area is divided into a radial network of roads radiating
from the centre outwardly with a block pattern network of roads in
between the radial main streets.
63

64
Advantages
~ Less risky as compared to the rectangular pattern.
~ It reduces the level of congestion at the primary bottleneck location.
~ If one radial road is blocked then another can be used as an alternative.
Disadvantages
~ Lack of safety appurtenances like rail transitions, crash attenuators and
post support bases.
~ It is only effective when two-lane ramp traffic does not have to merge at
the downstream end of the ramp.

3.Radial or Star and Circular Pattern
 It is the pattern in which the main roads(radial roads) radiates
from the central point and are connected with concentric
roads(ring roads) that are also radiating outwardly.
65

Advantages
 It is safe as compared to the above patterns because vehicles travel in the same
direction.
 Roundabouts present in this pattern improves the efficiency of traffic flow. This also
reduces fuel consumption and emissions of the vehicle.
 Using a circular pattern in place of traffic signals reduces the possibility of rear-end
crashes.
Disadvantages
 Providing a good curve during the implementation of this pattern is quite challenging.
 It affects the driving ability. Mainly, old drivers face this problem due to
declines(decrease) in vision, hearing, and cognitive functions.
 There is necessary proper provision of the traffic signal, road markings and lighting to
alert the drivers that they are approaching a roundabout.
 Splitter Islands should be extended far enough to provide pedestrian refuge (crosswalk)
and to delineate(describe ) the roundabout.
66

4.Radial or Star and Grid Pattern
a. This pattern is formed by the combination of Star and Grid
Pattern.
b. As in other, a radial network of road radiates from the centre
outwardly. Then, the main radial streets are interconnected by
providing a grid pattern.
67

Advantages
 It increases the efficiency of land usage and unit density.
 It improves the traffic flow in both directions utilizing Savannah’s
cellular structure.
 It provides high safety to vehicular traffic with a high proportion of 3-
way intersections.
 It reduces the cut-through traffic.
Disadvantages
 Splitter islands should be extended far enough.
 High construction cost because of the need for extra traffic signals,
road marking and lighting.
68

5. Hexagonal Pattern
a. In this, the entire area is divided into hexagonal patterns.
b. Three roads meet the built-up area boundary by the sides
of the hexagons at every corner of the hexagon which can be
further divided into suitable sizes.
69

Planning Surveys
70
 Highway planning phase includes
 Assessment of road length required for area
 Preparation of master plan showing the phasing of
plan
 Economic Studies
 Financial studies
 Traffic and rod use studies
 Engineering studies

Economic Studies
71
 Population and its distribution
 Trend and population growth
 Agricultural and industrial products
 Industrial and agricultural development and future trends
 Existing facilities with regard to communication, recreation
and education
 Per capita income
 Vehicle ownership

Financial Studies
72
 Sources of income and estimated revenue from
taxation on road transport
 Living standards
 Resources at local level, toll taxes, vehicle
registration and fines
 Future trends in financial aspects
 Public-Private Partnership basis : BOOT, BOT,
etc.
 Incentives for investors
 Other methods for raising funds

Traffic Studies
73
 Traffic volume in vehicles per day, annual
average daily traffic, peak and design hourly
traffic volume
 Origin and destination studies
 Traffic flow patterns
 Mass transportation facilities
 Accidents, cost analysis and causes
 Future trend and growth in traffic volume and
goods traffic, trend in traffic pattern
 Growth of passenger trips and the trends in the
choice of modes

Engineering Studies
74
 Topographic surveys
 Soil surveys
 Location and classification of existing roads
 Estimation of possible developments in all
aspects due to proposed highway
development
 Road life studies
 Special problems in drainage, construction
and maintenance of roads

Preparation of Plans
75
 General Area Plan
 Distribution of population
 Locations of places with their respective
productivity and quantity
 Existing road network with traffic flows and
desire lines

PRINCIPLE OF ROAD
ALIGNMENT
Road alignment is the position occupied by the centerline of a road
in the plan.
The centerline of the road is marked before its actual construction.
The cost of construction, maintenance safety and ease in travel
depend upon its alignment.
Therefore a road alignment should be selected carefully.
76

The basic objects of road alignment are as given below:
1.The alignment of the road should be as short as possible to provide economy in
the cost of construction.
2. The alignment should be as straight as possible which ensure higher speed to the
traffic and lower cost of construction.
3.The alignment should be easy for construction, maintenance, and traffic
operations.
4. The alignment should cross the railway lines and other roads and bridge at right
angles.
5. It should cross the rivers, canals or streams, etc. a place where its width is
minimum.
6. The alignment serves the maximum population connecting intermediate important
towns and group of villages.
7. The alignment should pass through regions of natural beauty and scenery.
8.The alignment should be such that crosses the minimum number of bridges,
crossings, culverts, and embankment.
9. It should provide smooth curves and easy gradients.
10. It should be such that minimum earthwork in embankment or cutting is done.
77

 Road alignment is the positioning of the centerline of the
highway or road. It is also called highway alignment.
 Simply, it is the direction through which the road will pass.
 Road alignment provides proper guidance to pass the road
through the alignment which is most economical, easy to
construct, and free from conflicts.
 There are two types of road alignment.
 a. Horizontal Alignment
 It includes straight stretches, curves, etc.
 b. Vertical Alignment
 It includes upward or downward gradients.
78

Horizontal Alignment of Roads
• Horizontal alignment is a straight portion of the road which is
connected by suitable curves.
• All the curves of roadway need a superelevation for banking of
the curve, to resist vehicles from slipping, allow all the vehicle to
run at a uniform speed.
• Horizontal alignment is designed on some basic rules and
regulations like driver limitations, curve radius, vehicle
characteristics, cost, profile, design speed, etc.
79

Horizontal Alignment of Roads
Classification of Horizontal Alignment:
There are mainly four types of classification are observed, those
are-
 Simple Curve.
 Spiral Curve.
 Reverse Curve.
 Compound Curve.
An object of Horizontal Alignment:
 Horizontal alignment increases the adequate level of the user.
 Horizontal alignment secures the safety of the road user.
80

Vertical Alignment
 Vertical alignment of the road comprises of gradients and vertical
curve. Vertical alignment is defined as the height and depth in a
vertical axis with respect to the horizontal axis, this height and
depth, it creates a gradient and vertical curve.
Vertical alignment of roadway consists of the following factors-
• Gradient.
• Grade Compensation.
• Vertical Curve.
81

82
Highway Alignment
Highway Alignment is the position or layout of the centre line of the highway on the ground is called the alignment.
It includes a straight path, horizontal deviation, and curves.
Alignment of Road
It is the direction through which the road will pass. Road alignment provides proper guidance to pass the road through
the alignment, which is most economical, easy to construct, and free from conflicts. There are two types of road
alignment. It includes straight stretches, curves, etc.
Alignment in Design
Alignment is a design principle that refers to lining up text or graphics on a page. A design with poor alignment will
look cluttered and unfinished. But aligning elements on the page will organize your design and make it easier to read.
Horizontal Alignment Definition
The horizontal alignment is the route of the road, defined geometrically as a series of horizontal tangents (straight
roadway sections), circular curves, and spiral transitions. It shows the proposed roadway location in relation to the
existing terrain and adjacent land conditions.
Road Alignment
Road alignment is the positioning of the centerline of the highway or road. It is also called as highway alignment.
Simply, it is the direction through which the road will pass. Road alignment provides a proper guidance to pass the road
through the alignment which is most economical, easy to construct and free from conflicts.
Vertical Alignment of Road
The vertical alignment of a road consists of gradients(straight lines in a vertical plane) and vertical curves. The vertical
alignment is usually drawn as a profile, which is a graph with elevation as a vertical axis and the horizontal distance
along the centre line of the road as the horizontal axis.

Result of Improper Road Alignment
Improper road alignment leads to the following:
a. Increase in the rate of accidents.
b. Increase in construction and maintenance cost.
c. Increase in the vehicle operating cost and also leads to the discomfort of
the users.
d. The decrease in durability and strength of the road.
83

Factor Controlling Road Alignment
1. Class & Purpose
The alignment of the road is affected by class and purpose. National and state highways
between two stations must be aligned straight as much as possible whereas, in the case of other
types of roads, a deviation may be allowed where it is found necessary.
2. Obligatory Points
Obligatory points define the way through which road should be passed and through which road
should not be passed.
The roads are usually built for the development of the areas. Therefore, road alignments must
necessarily pass through important towns, groups of villages, and places of religious, social,
political, and commercial importance.
Road alignment should not be passed through historical places, cultural places, etc.
3. Type of Vehicular Traffic
In the case of fast-moving traffic, the road alignment must be straight as possible.
In the case of low traffic, the alignment may even have sharp turns.
4. Gradient
The alignment of roads should be selected such that longitudinal slopes are not steeper than the
ruling gradient. To achieve this, the alignment might need a deviation from the straight line.
84

Factor Controlling Road Alignment
5. Horizontal Curves
In the case of national and state highways, the radius of the horizontal curve must not be less
than 230 m otherwise the alignment must be improved.
6. Sight Distance
The alignment of roads must be decided such that more and clear sight distance is available for
drivers of the vehicles.
7. Obstructions
Obstruction also affects alignment selection. For example, the alignment should be improved to
avoid marshy land, ponds, wells, graveyards, historical, monumental, and religious sites, etc.
8. Economical Factor
Road construction becomes economical when the road alignment is straight. So, straight
alignments should be given priority.
9. Availability of Construction Materials
Construction material should be easily available. Abundant materials lead to a higher cost of
materials. This directly affects the economical condition.
85

Steps in Design of Road Alignment
Steps in Design of Road Alignment
There are four major steps in road alignment. They are:
a. Map Study
The first step of road alignment is map study. Generally, geographical and contour maps are
studied.
This helps to know the position of natural features like ponds, rivers, lakes, hills, etc. This also
helps to learn about different alternative alignments.
b. Reconnaissance Survey
Reconnaissance is a rough survey done by visiting the field.
Positions of natural features in the field are cross-checked as indicated in the map.
If some features are not indicated in the map then such features are included. It also includes
the collection of data like several cross-drainage structures, high flood levels, soil
characteristics, etc.
Report of selected alignment is also prepared that includes the merits, demerits, and profile map
of scale 1:50,000.
86

c. Preliminary Survey
The main objectives of the preliminary survey are:
1. To analyze the different alternatives to the road alignment.
2. To estimate the cutting and filling required in the construction.
3. To survey the alignments proposed by the reconnaissance survey.
4. To finalize the alignment among different alternatives.
d. Detailed Survey
It is the final step before starting the construction work. Detailed study of the following is done:
1. Soil Study
2. Hydrological Survey
3. Construction cost and time
4. Return on investment
5. Present and Future Traffic
87

Reference
1) I.R.C Codes.
2) Text book Highway Engineering by S.K Khanna & C.E.G Justo
3) Google.com
88

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