Transcript LEC - 01 - wec civilians

Transportation is a way of moving people or
things from one place to another.
Land (roads and
railways)
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Water(seaports)
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Air(airports)
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Highway engineering is an engineering discipline
branching from civil engineering that involves the
planning, design, construction, operation, and
maintenance of roads, bridges, and tunnels to
ensure safe and effective transportation of people
and goods
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Traffic engineering is a branch of civil
engineering that uses engineering techniques
to achieve the safe and efficient movement of
people and goods on roadways.
It focuses mainly on research for safe and
efficient traffic flow, such
as road geometry, sidewalks and
crosswalks, segregated cycle facilities, shared
lane marking, traffic signs, road surface
markings and traffic lights.
Traffic engineering deals with the functional
part of transportation system, except the
infrastructures provided.
There are three main elements of automobile
transportation:
 The road users (Drivers and pedestrians)
 The vehicle
 The road way and geometric design of roads
Depending on weather
• All weather roads
• Fair weather roads
Depending the
type of Carriage way
National highway act ( 1956
• Paved roads
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• Unpaved roads
Depending upon the pavement surface
• Surfaced roads
• Un surfaced roads
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Based on the Traffic Volume
Heavy
Medium
Light
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Primary
Expressways
National Highways
Secondary
State Highway
 Major District Roads
Tertiary
Ordinary district Roads
 Village Roads
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Heavy traffic at high speed (120km/hr)
Land Width (90m)
Connects major points of traffic generation
No slow moving traffic allowed
No loading, unloading, parking.
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The National Highways of Pakistan consists of all
public highways maintained by National Highways
Authority under the Ministry of Transport.
It maintains over 12,000 kilometres (7,500 mi) of
roadways organised into various classifications
which crisscross the country and provide access to
major population centres..
All national highways in Pakistan are pre-fixed with
the letter 'N' (for "National") followed by the unique
numerical designation of the specific highway (with
a hyphen in the middle), e.g. "N-5". Each numerical
designation is separated by five numerals, i.e. N-5,
N-10, N-15, etc.
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They are the arterial roads of a state,
connecting up with the national highways of
adjacent states, district head quarters and
important cities within the state.
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Important roads with in a district serving
areas of production and markets , connecting
those with each other or with the major
highways.
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Roads serving rural areas of production and
providing them with outlet to market centers
or other important roads like MDR or SH.
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They are roads connecting villages or group
of villages with each other or to the nearest
road of a higher category like ODR or MDR.
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ARTERIAL ROADS
SUB ARTERIAL
COLLECTOR
LOCAL STREET
PATHWAY
DRIVEWAY
All roads
arterials
principle
Full control
interstates
Freeways/expresways
Non arterials
minor
uncontrolled
local
collector
major
minor
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Arterials primarily serve long-distance travel
and are typically designed as either access
controlled or partially access controlled
facilities with limited locations at which
vehicles can enter or exit the roadway
(typically via on- or off-ramps).
Design Speed : 80km/hr
Land width
: 50 – 60m
Divided roads with full or partial parking
Pedestrian allowed to walk only at
intersection
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Less mobility than arterial.
Design speed
: 60 km/hr
Land width
: 30 – 40 m
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As their name implies, Collectors “collect” traffic
from Local Roads and connect traffic to Arterial
roadways.
Collector routes are typically shorter than Arterial
routes but longer than Local Roads.
(Collects and distributes traffic from local streets
Provides access to arterial roads
Located in residential, business and industrial
areas.
Full access allowed.
Parking permitted.
Design speed : 50km/hr
Land Width
: 20-30m
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Design Speed : 30km/hr.
Land Width
: 10 – 20m.
Primary access to residence, business or
other abutting property
Less volume of traffic at slow speed
Origin and termination of trips.
Unrestricted parking, pedestrian movements.
(with frontage access, parked vehicle, bus
stops and no waiting restrictions)
Engineering Surveys for Highway locations
1)
Provisional alignment Identification ( Map
study)
2)
Reconnaissance survey
3)
Preliminary survey
4)
Final location to determine center line and
detailed survey
Art of observing and making
measurements of relative
portions of natural and manmade
features on the surface of earth
and plotting these measurements
to some suitable scale to
form a map.
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Highway surveys involve measurement and
calculation of distances, angles (horizontal and
vertical) and elevations.
 The data is then used to form a base map
with contour lines and longitudinal crosssections.
Three major categories
1. Ground Surveys
Basic equipment is used for location survey
 Measuring Tape.
 Levels.
 Theodolite.
 Electronic distance measuring devices
(EDM’s).
2. Remote Sensing
 Measurement of distances and elevations by
using devices located above the surface of
earth.
 Data is collected through airplanes and
satellites using global positioning systems
(GPS).
 Photogrammetry (data is obtained with the
help of aerial photographs) is the most
commonly used technique.
3. Computer Graphics
 Available/collected data is compiled and
stored in the electronic form.
 Photogrammetric and general survey data is
combined digitally with the help of softwares.
 The files can then be plotted in the form of
maps.
Location controls are basically the factors that
effects the selection of location of a highway
Major factors are:
 Topography.
 Soil Characteristics.
 Environmental factors (noise and air
pollution).
 Economic factors.
Highway location process have four phases
 Desk study of available data/information
 Reconnaissance survey
 Preliminary location survey
 Final location survey
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Available data in the form of reports,
maps,aerial photographs and charts is
studied.
Data is obtained form government
authorities e.g. transport department (NHA),
geological survey of Pakistan etc.
Similarly, information is required to be
obtained on hydrology, mining, agriculture
and weather.
Data is obtained on the following
characteristics:
 Engineering (topography, geology, traffic
volume and climate)
 Social (land use trends and zoning)
 Environmental (air, noise and water
pollution, wildlife, historic and archaeological
sites)
 Economic (construction cost, agricultural,
commercial and industrial trends)
“Reconnaissance is the process of identifying
several possible routes & evaluating the
feasibility of these routes for a highway
between specific points”
 Aerial photographs are often used for the
purpose, especially for rural areas.
Feasible routes are identifies by keeping in
mind the following factors
 Terrain and soil conditions.
 Serviceability of route to industrial and
residential areas.
 Crossing of other transportation facilities like
rivers, rail and highways.
 Route directness.
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Identification of control points for each
feasible/selected route.
Routes are then plotted on a map.
The position of the feasible routes are set as
closely as possible by Establishing all control
points.
 Determining preliminary vertical and
horizontal alignments of each control point
 Economic and environmental feasibility of
the routes
 The best route is then selected as the
preliminary alignment for the highway.
Initial cost of the project and future
economic effects
 Road user cost
 Construction cost
 Road user benefits
 Economic drawbacks from the project
Information also helps in deciding the type of
highway for a particular route.
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Environment Includes
 plant
 animals
 Human community
 Effects on quality of life for all (animals and
human being)
An environmental impact statement should be
submitted which should include
 Available alternatives
 Assessment of all positive and negative
impacts
 Short and long term effects
 Unavoidable adverse environmental effects
 Use of natural resources
 Each route should be studied
e.g. Positive and negative effects of at grade or
grade seperated intersection.
Detailed layout of the selected route is carried
out at this stage
 Centreline of the road.
 Horizontal and vertical alignment.
 Property lines.
 Intersecting roads.
 Position of structures and drainage channels.
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Transferring the alignment on to ground.
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Detail Survey – levelling work for longitudinal and
transverse direction.
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Intervals for cross sectional levelling
 Plain
50 – 100m
 Rolling 50 – 75m
 Built up 50m
 Hilly
20m
Soil Profile
Factors that effect location of highway in urban
areas
 Connection to local streets (which street to
connect,traffic flow)
 Right-of-way acquisition (land cost, road on
elevated structures, noise and aesthetics)
 Coordination with other transportation systems
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Provisions for bicycles and pedestrians
(sidewalks,crosswalks, traffic control devices,
ramps, bicycle path)
Elements of
comparison
Conventional
Modern
Maps- Base
material
Topo sheets
RS data, Aerial Photos,
Satellite Imageries
Instruments
Chains, Tapes, Theodolite,
Dumpy levels
EDM, Total Station, GPS,
Auto and Digital Level,
Photogrammetry.
Accuracy
Chain/Tape 1 in 3000 to 1 in
30,000
Tacheometer 1 in 1000 to 1 in
10,000
EDM/TS 1 in 10000 to 1 in
1,00,000
Photogrammetry. 1 in 10000
to 1 in 1,00,000
Plotting
CAD Systems
Software
Errors
Human errors
Closing Errors hence re
measuring is required.