MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION

(Autonomous)
(ISONEC - 27001 - 2013 Certified)

WINTER- 2022 EXAMINATION

Subject Name: Traffic Engineering Model Answer Subject Code: 22507

Important Instructions to examiners:

I) The answers should be examined by key words and not as word-to-word as given in the model answer scheme.
2) The model answer and the answer written by candidate may vary but the examiner may try to assess the
understanding level of the candidate.
3) The language errors such as granmmatical, spelling errors should not be given more importance (Not applicable for
subject English and Communication Skills.
4) While assessing figures, examiner may give credit for principle components indicated the figure. The figures
drawn by candidate and model answer may vary. The examiner may give credit for any equivalent figure drawn.
S) Credits may be given step wise for numerical problems. In some cases, the assumed constant values may vary and
there may be some difference in the candidate's answers and model answer.
6) In case of some questions credit may be given by judgement on part of exanminer of relevant answer based on
candidate's understanding.
7) For programming language papers, credit may bc given to any other program based on cquivalent concept.
8) As per the policy decision of Maharashtra State Government, teaching in English/Marathi and Bilingual (English +
Marathi) medium is introduced at first year of AICTE diploma Programme from academic year 2021-2022. Hence
if the students in first year (first and second semesters) write answers in Marathi or bilingual language (English
+Marathi), the Examiner shall consider the same and assess the answer based on matching of concepts with model
answer.

Q. Sub
Answer Marking
No Q No Scheme
Attempt any FIVE of the following: 10 M
a) State the various scope of traffic Engineering. 02M
Ans. The study of traffic engincering includes -1Study of Trafficcharacteristics I/2M
2 Traffic stucdies & analysis 3 Traffic planning & analysis 4 Traffic Geometric Design Each
5 Traffic operation ,regulation & control 6 Road Safety aspect (any 4)
7Administration &Management.
b)| List out the factor afecting gradients 02M
Ans. 1.Nature of the ground. I/2M
cach
2.Drainage required. (any 4)
3.Nature of the traffic.
4.The type of road surface.
S.The total height to be covered. 6.Road and railway interaction. 7 Safety Required.
c) Give the purposes of traffic studies 02M
Ans.
i)To collect the data about typc and volume of traffic at prescnt and to cstimate thc same
that the road is expected to carry in near future. I/2M
ii) To decide the pavement thickness of the road. cach
ii) To decide the geometrical design of the road.
iv) To decide the drainage system, bridges, culverts cetc
d Classify the road signs 02M
Ans. Roads sign are clasify in to following three categories: 0IM
1)Mandatory sign-These signs are used to inform road users of certain laws each
and regulations to provide safety and free flow of traffic. (any 2)
2)Warning sign-These signs are used to warn the road users of the existence of certain
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 MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION
(Autonomous)
(ISONEC-27001 - 2013 Certified)

WINTER- 2022 EXAMINATION

Subject Name: Traffic Engineering Model Answer Subject Code: 22507

hazardous condition cither on or adjacent to the roadway

3)Informatory sign-These signs are used to guide road users along routes, inform them
about destination and distance., and provide other information so as to make the road
travel casicr, safe and pleasant.
e) State the purpose of segregation of traffic. 02M
Ans. 1)To increase the capacity of lanes. 01M
2)To increcase the speccd of vehicles Each
3) To decrease the number of accidents. (any 2)
4)To cnsure more uniform use of the entire roadway width. 5) To separate incoming &
outgoing traffic at a road intersection
Define Summit curves 02M
Ans. Summit Curve: The vertical curves having their convexity upward are known as summit curves. 02M
Give the requirenments of traffic control devices 02M
Ans. The traffic control devices must meet the following basic requirements: 1M
I. It should provide a good visual guide to road users.
2. It should provide timely warning of the hazardous situation other important each
information.
It should not involve heavy maintenance expenditure. (any 2)
It should involve a low initial cost.
5. It should have an aesthetically pleasing expericnce,
Q-2 Attempt any THREE of the following: 12 M
a) Describe the factor affecting the PCU 4M
Ans. Following are the various factor affecting PCU Values:
I) Dimensions of vehicles such as width and length.
2) Dynamic characteristics of vehicles such as power, speed, acceleration and braking.
3) Transverse and ongitudinal gaps or clearance between moving vehicles which
depends upon the speeds, driver characteristics and the vehicle classes at the adjoining 01M
spaces. each
4)Traffic stream characteristics such as composition of different vehicle classes, mean
speed and speed distribution of the mixed traffic stream and volume to capacity ratio. (any 4)
5) Roadway characteristics such as road geometrics including gradient and curves,
access controls, rural or urban road, presence of intersections and the type of
intersections.
6) Regulation and control of traffic such as speed limit, one way traffic, presence of
different traffic control devices ete

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 MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION
(Autonomous)
(ISOIEC- 27001 -2013 Certified)

WINTER-2022 EXAMINATION
Subject Name: Traffic Engineering Model Answer Subject Code: 22507

b) Explain the use of various traffic control devices for smooth traffic flow 4M

Ans. The various types of traffic controlling devices are as follows:

i)Traffic signs or Road signs -Traffic signs are one of the best ways to divert vehicles, 01M
regulating traffic by informing them of when they necd to stop or by displaying typical
speed limits. Depending on the extent of the roads on the property, different
precautionary signs may be ideal, such as signs that indicate a merging point,
roundabout, or turn options.
ii) Traffic markings or Road markings- Another type of traffic safety device is
applicd to the road itself. Specifically, these markings will include: 01M
Pavement markings - Markings on the road itself that are typically made of white pain,
with ycllow markings indicating parking restrictions or lanes.
Kerb markings - Along roadside curbs, these markings can indicate parking regulations
and more, and may appear with altcernating black and white lines to incrcase visibility
from a longer distance.
Objcct markings Certain physical obstructions and hazards may include spccific
labels to warn drivers and pedestrians.
ii) Traffic signals
Properties can use traffic signals along with signs to dircct traffic, in the form of simple
traffic lights. Traffic signals should typically meet the criteria of bcing able to draw 01M
attention, provide meaning and sufficient time to respond, and to minimize wasted
time. Traffic control signals normally include a clear grecn, yellow, and red light to
manage traffic flow, while pcdestrian signals indicate when it is safe for them to cross
designated cross-walk.
iv) Traffic Islands-Traffic Island is physical structure or a painted object found on
roads and roadside. Traffic island serve various purposes depending it type. It is
01M
usually seen as a raised area along the road for a better & orderly flow of traffic or act
as a stopping/ resting arca for pedestrians. These may be raised structures made up of
concrete or aphysical structure in form of boards, barricades, traffic cones ete
Justify the need of various carriageway marking 4M
Ans. The Nccd of various carriage way markings are:
i) Centre line marking: They are provided on two way roads to separate the streams of
01M
traffic moving in opposite direction. cach
ii)Traffic lane marking: They are provided on multi lane road to guide the traffic and
to properly utilize the carriageway. (any 4)
iii)No passing zone marking: They are provided to indicate to the road users that
overtaking is not permitted in that much portion of the road.
iv) Pedestrian crossing or cross walk line: They are provided at places where
pedestrians have to cross the road.
v) Stop lines: They are provided near the pedestrian crossing to indicate to the driver to
stop and then to procced when signal is grecn.
vi) Markings at approaches to intersections: They are provided near intersections to
designate proper placement of vehicles before turning to different directions.
vii) Parking space limit marking: They are provided for proper utilization of parking
facility.
viii)Obstruction approach marking: They are provided to indicate that there is some
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 MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION
(Autonomous)
(ISO/IEC-27001 - 2013 Certified)

WINTER- 2022 EXAMINATION

Subject Name: TrafficEngineering Model Answer Subject Code: 22507

obstruction in the form of monument within the carriageway so as to prevent vehicles

from colliding with the obstruction.
d 4M
Draw neat sketches of typical prohibitory sign post and Right turn prohibited
Sign
An
Right turn prohibited Sign

02M

prohibitory sign post

Red dieo
SOonm daneter

03M
(Fig)
Doinatton
plate
A200mn 01M
Label
blnek awith
nd
n d white
bands
2800rmm
160m

around l e v e T
prohibitory sign post

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 MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION
(Autonomous)
(ISO/IEC - 27001 - 2013 Certified)

WINTER-2022 EXAMINATION
Subject Name: Traffic Engineering Model Answer Subject Code: 22507

Q-3 Attempt any THREE of the following: 12 M

a Enumerate the advantages of traffic signal. 4M

Ans. Advantages of traffic signals are

01M
I. Traffic signals help for movement of traffic securely without any collision. Each
(any 4)
2. They can reduce the number of accidents on roads like pedestrian accident and right
angle collision of two cars.

3. Signals can increase the capacity of traffic handling at the intersection.

4.The traffic signals help for the safe movement of slow-moving traffic by interupting
heavy traffic at regular intervals.
5. The indications of the signals can be seen casily in foggy weather or at night time.
Without signaling system, it is very difficult to control traffic by the traffic policenman
at night or in foggy weather or on a rainy day.

6. Traffic control by signals is accurate and cconomical as compared to traffic police

control.

7. Under favorable conditions, they provide for continuous motion of traffic along a
specified path.
b Compare the fixed time signal with manually operated signals. 4M
An Fixed time signal Manually operated signal.
1. These are pre-time signals which are I. These signals are those in which 01M
set to repeat regularly a cycle of red, timings of the phase and cycle are each
yellow and green lights. changed according to traffic demand.
2. Traffic personnel is not required. 2. Traffic personnel is required.
3. It is suitable where traffic demand on 3. It is suitable where traffic demand on
different routes remain constant different routes changes during the day.
throughout the day.
4. Initial cost is high. 4. Less expensive.

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 MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION
(Autonomous)
(ISOEC - 27001 - 2013 Certified)

WINTER-2022 EXAMINATION
Subject Name: Traffic Engineering Model Answer Subject Code: 22507

C) Discuss the factorsaffecting lighting scheme of roads. 4M

Ans.
1) Contrast: The contrast is one of the most important contributing factors for the
visual performance during night driving. To a great extent, the recognition of objects is
based on the discrimination of differences of brightness between an object and its
background.
2)Glare: The disturbing influence when viewing a difficult visual task under low 0IM
brightness conditions is known as glare. Following two types of glare have a critical each
influence on the visual performance of a driver: Disability glare or physiological glare (any 4)
and Discomfort glare or psychological glare.
3) Lamps: The lamps commonly used for highway lighting are tungsten filament
lamps, sodium vapour lamps, mercury vapour lamps and fluorescent lamps.
4) Lateral placement of lighting poles: The lighting poles should not be installed
very close to the pavement edge because in that case, the capacity of the roadway is
decreased and the free movement of traffic is obstructed.

5) Lighting layouts: The highway lights can be arranged in different ways as opposite
arrangement, staggered arrangement, one side arrangements, central arrangement or in
combination.

6)Luminaire distribution of light: For making the maximum use of luminaire or

source of light, it is desirable to have proper distribution of light.
7) Mounting height and overhang: The mounting height plays a great role in deciding
the distribution of light, shadow and glare effect from the street lamps. The usual
mounting heights range from 6 m to 10 m. The higher value is preferred for important
urban roads.

8) Spacing of lighting units: The spacing between lamps on straight roads is about 3
to 5 times the mounting height. For sharp curves, the spacing betwecn lamps is closer
for better visibility and comfort conditions.
d Describe the points to be considered for the roadside development. 4M
Ans. Following are some of the points to be considered for roadside development
1.Consistent and smooth horizontal and vertical alignments. 01M
2.Wide right of way in urban areas to screen adjoining property by plantation each
3. Flat sides slopes in embankment and cut, rounded to blend to the original surface. (any 4)
4. Suitable planting of roadside trees and shrubs and proper maintenance.
5. Turfing on side slopes and shoulders of a rural road.
6. Developing a pleasant view and parking spaces.
7. Street lighting and Road arboriculture (planting trees on the road side) are
important aspects of roadside development.
8.In urban areas roadside planting is mainly for beauty or landscape. Planting of
shrubs is done on wide urban roads on the medians or separators besides providing
trees on roadsides. During night drive these shrubs helps to reduce the headlight glare.
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 MAHARASHTRA STATE BOARD OF TECHNICALEDUCATION
(Autonomous)
(ISOIEC - 27001 -2013 Certified)

WINTER-2022 EXAMINATION
Subject Name: Traffic Engineering Model Answer Subject Code: 22507

Q-4 Attempt any THREE of the following: 12 M

a
Discuss the purpose of planningtrees and shrubs. 4M
Ans. 1.To provide attractive landscape on the roadside.
2. To provide shades to the road user. 01M
3. To interrupt the annoying sound waves and fumes from road vehicles. each
4. Prevention of glare from the headlight of incoming vehicles. (any 4)
5. To provide Job to local people.
6. To lessen the impact of noise pollution caused due to increase in number of vehicles.
7. We get fruit bearing trees and timber.
8. To decrease the impact of air pollution and dust.
b Suggest various measures to prevent road accidents. 4M
Ans. Following measure/remedies are suggested to prevent road accidents:
) Engineering Aids 1M
2)Enforcement Aids Three E's
3) Educational Aids
Engineering Aids/Measures
I. By checking and Rcdesigning the Road gcometrics, if nccessary (sight distance,
width of pavement, Horizontal alignment, vertical alignment)
2. By providing Required Traffic control devices (signs, Markings, signals, islands)
3. By providing proper pedestrian crossing ncatly lincd in white colors for pedestrians
to cross the road.
4. By providing footpaths along both sides of the Road subjected to heavy intensity of IM
Traffic in urban arcas.
5. By segregation of Traffic on urban roads subjccted to heavy intensity of traffic.
6. By improving road Intersections with the provision of traffic signals, rotary.
channeling islands or grade separations.
7. By providing adequate lighting especially at road intersections.
8. By "Before & After" studies of Road accidents.
Enforcement Aids:
Traffic police should be engaged on important and busy road junctions to guide thc
vehicles. Traffic police should also be given power to prosccute drivers for committing
traffic offenses, breaking the rules, driving at excessive spccds, disobeying the signals.
driving on wrong sides & making wrong turns.
-Speed control.
Traffic control devices.
IM
Training && supervision (License, Driving schools)
-Medical check (Tested for vision once in 3 years)
Observance of law &regulation.
Educational Aids:
Road users should be educated so as to know the importance of cultivating road
manners & road senses.
Rules of Road
Correct manner of crossing IM
Posters & slide shows regarding safety should be displayed
- This knowledge should also be given to children, schools, parents.
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 MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION
(Autonomous)
(ISO/EC - 27001 - 2013 Certified)

WINTER- 2022 EXAMINATION

Subject Name: Trafic Engineering Model Answer Subject Code: 22507

c) Explain the considerations to be taken for road safety. 4M

Ans. Points to be considered for road safety are:
I) The road should be designed to proper standards, built to the correct spccifications &
maintained adequately. IM
2) The safe specd at which the Vehicle can negotiate a curve depends on the Radius of each
curvature of the curve. Sharp curves permit low spceds & large Radii curves cater high (any
design speeds. four)
3) For a Vehicle to negotiate any curve at the desired speed, the road should have
adequate super elevation. Deficiency of super elevation can cause serious Accidents.
4) The Minimum carriageway width for two-way road should be 7m to cater for 2
lanes of Traffic.
5) Properly designed & Maintained Road signs inform the driver of need for caution &
can avoid accident.
6) Guard Rails and safety barriers prevent vehicles form going off the Roadway in the
event of loss of control.
7) Improved visibility & good street lighting also reduces the number of accidents to
about 30%.
8) Channclization Islands Reduces the number of Collision points & hence promotes
safety.
d) Describe the various objectives of road accident studies. 4M
Ans. Some objcctives of accident studies are listed below:
To study the causcs of accidcnts and suggest corrective mcasures at imp location. 1M
2.To evaluate existing design. each
3To compute the financial losses incurred. (any
4To support the proposed design and provide cconomic justification to the four)
improvement suggested by the traffic engineer.
5To carry out before and after studies and to denmonstrate the improvement in the
problem.
e Explain the legislation and law enforcement, education in road accident studies. 4M
Various Legislative Measures have been adopted like 02
1. Age limit of drivers (any 4)
2. Penalties of fine on License for careless driving.
3. Enable Police to check the drivers for the drunkenness.
4. Prescribe Rules for cyclists.
5. Prescribe Rule for Motorcycle & Scooter Riders.
6. Lay rules for parking of vehicles.
7. Control loading & unloading of goods. (Size & weight of vchicles)
8. To make third party Insurance compulsory.

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 MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION
(Autonomous)
(ISo/IEC- 27001 - 2013 Certified)

WINTER- 2022 EXAMINATION

Subject Name: Traffic Engineering Model Answer Subject Code: 22507

Ans. Law enforcements.

1. Legislation by itself cannot be able to archive its objective unless it is enforced 01M
rigidly. The enforcement is in the hands of police department in cooperation with (any 2)
Traffic courts.
2. The Police force should be adequately strengthencd to deal with detection.
3. The work of the police is Rendered casy in cases of detection of offenses such as
exceeding speed limits by Mechanical aids.
4. The Radar speed measuring instrument can record the speed Instantly.
5. Breath Analysis can detect the drunken driver.
6. Police Patrols in Vehicle cquipped with wireless phones are of great help.
Education

1. It is very essential to educate the Road users for the various measures to use the
roadway facilities with safety. 01M
2. The passengers & pedestrians should be taught the rules of the road, correct manner (any 2)
of crossing etc.
3. By introducing necessary instructions in schools and colleges for children.
4. Posters exhibiting serious results due to carelessness of road users can be useful.
Q-5 Attempt any TWO of the following: 12 M
a Explain the methods of parking studies, stating the necessity of it. 6M
Ans. Methods of Parking studies:
1. Inventory of Parking facility:
Details are collected on current status of parking facilities. these detail includes location, 2M
condition, number of parking spaces, parking rates, its time limit, layout, ownership of
vehicle etc.
2. Accumulation counts:
The data is obtain by conducting a study which includes number vehicles park at particular
period of time. Also the number of vehicle already present in that area is counted along with
this number of vehicle incoming and number of vehicle outgoing are noted and added or
subtracted from the total number of vehicles. 2M
3. User information survey:
The user individually provide information that not achieved by license plate method, parking
interview and post card method are taken into consideration.
Necessity: 2M
1. To avoid congestion
2. To avoid accident.
3. To analyze existing design.
4. To calculate parking demand.
5. To understand trafficcharacteristics.

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 MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION
(Autonomous)
(ISoNEC - 27001 - 2013 Certified)

WINTER- 2022 EXAMINATION

Subject Name: Traffic Engineering Model Answer Subject Code: 22507

Explain the various forms of representation of traffic volume count data. 6M

Ans. Traffic volume count varies considerably with time hence several types of
measurement of volume are commonly represcnted to average thesc variations. The
various forms of representation of traffic volume data count as follows:
1. Average Annual Daily Traffic (AADT);:
This is given by total number of vehicles passing through a section in a year divided by 01M

365. This can be used for measuring the present demand for service by the street or
highway.
2. Average Daily Traffic (ADT): 01M
An average of 24-hour traffic volume at a given location for some period of time less
than a year. An ADT is a valid number only for the period over which it was measured.
3. Traffic Composition:
There are two broad classes fast moving vehicle and slow-moving vehicle. Undcr fast 01M
moving vehicle there are other different classification like two-whecler, three-whecler
and four-wheeler etc. slow moving consist of carts, bicycles etc.
4. Design Hourly Volume:
It is the cconomic hourly flow of future ycar, which is use for designing geometric 01M
features of roadway.
5. Rate of flow:
01M
Rate of flow use to express an cquivalent hourly rate for vehicles passing a point along
roadway or for traffic during interval less than Ihour.
6. Saturation Flow:
01M
The maximum hourly rate of an approach at a signalized junction.
Q-6 Attempt any TWO of the following: 12 M
a) Explain the various types of traffic Island along with neat sketch. 6M
Ans. 1. Rotary Island or Central Island:

A traffic Island constructed in center of an intersection to compel movement of traffic 01M

in Clock-wise dircction called rotary or central islands. Rotary Islands are of (explan
following shapes. I) Circular 2) Squarish with rounded edges 3) Elliptical, clongated or ation)
oval 4) Rectangular.

01M

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 MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION
(Autonomous)
(ISO/NEC-27001 - 2013 Certified)

WINTER-2022 EXAMINATION
Subject Name: Traffic Engineering Model Answer Subject Code: 22507

b) Explain with neat sketch condition diagram and symbols commonly used along 6M
with typical condition diagram.
Ans. A condition diagram is a drawing to scale showing all important physical conditions of an
accident location to be studied. The important features generally to be shown on in the 02M
condition diagram with their dimensions marked are width of roadway, shoulders, medians,
curves, kerb lines, bridges culverts, clectric posts, trees & all details of road conditions.
Obstruction to vision, property lines, signs & signals.

boa.
02M

Condition diagram
02M
Driveway
Pavernent marking
7111T Embankment

Building
Billboard
Trees
Shrubs

Hydrant
Uility pole
Traffic signal
Traffi sign
Street light
Pedestrian signal

Symbols use along with typical condition diagram

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 MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION
(Autonomous)
(ISONEC- 27001 - 2013 Certified)

WINTER- 2022 EXAMINATION

Subject Name: Traffic Engineering Model Answer Subject Code: 22507

c) Draw the sketch of rotary interchange and diamond type of grade interchange. 6M
Ans.

03M

Rotary interchange

03M

Diamond type of grade interchange

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