chapter 2 traffic studies

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Chapter-2 TRAFFIC STUDIES

Prepared By: Ankit N Patel

Traffic Engineering

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Prof. Ankit Patel

2Traffic Studies

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Traffic studies are carried out to analyze the traffic characteristics. These studies helps in deciding the geometric design features traffic control for safe and efficient traffic movement.•The various traffic survey studies generally carried out are: Traffic volume study Speed study Spot speed study Speed and delay study Origin and destination study Traffic flow characteristics Traffic capacity study Parking study Accident studies

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3Traffic Volume Study

It is the number of vehicles crossing a section of road per unit time at any selected period.

It is used as a quantity measure of flow: the commonly units are vehicles/day or vehicles/hour

Object and Uses of Traffic Volume Study: It is generally accepted as a true measure of the relative

importance of roads and in deciding the priority for improvement and expansion.

It is used in planning, traffic operation and control of existing facilities and also for planning the new facilities.

It is used in the analysis of traffic patterns and trends. Useful in structural design of pavement Pedestrian traffic volume study is used for planning side walk,

cross walks, subway and pedestrian signals.

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Scopes of Volume Study

SCOPES

Design

Planning

Improvement

Dynamic Traffic

Management

Estimating Highway

Use

Computing Accident

Rates

Traffic Stream

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Main Methods of Counting

• 1. Direct Method• 2. Indirect Method

Manual Counting Method

• 1. Contact System• 2. Contact-less System

Automatic Counting Method


Prof. Ankit Patel

6Manual Method

counts are typically used to gather data for determination of vehicle classification, turning movements, direction of travel, pedestrian movements, or vehicle occupancy. Most applications of manual counts require small samples of data at any given location. Manual counts are sometimes used when the effort and expense of automated equipment are not justified. Manual counts are necessary when automatic equipment is not available. Manual counts are typically used for periods of less than a day. Normal intervals for a manual count are 5, 10, or 15 minutes. Traffic counts during a Monday morning rush hour and a Friday evening rush hour may show exceptionally high volumes and are not normally used in analysis; therefore, counts are usually conducted on a Tuesday, Wednesday, or Thursday.

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Manual counts• A manual classified count (MCC) involves counting all the

vehicles passing a selected location on a road for a pre-determined period of time.

• The count is conducted by persons standing at the roadside and recording passing vehicles on a form, hence the term “manual traffic count”. This distinguishes it from counts by machines that can record passing vehicles automatically, which are know as “automatic traffic counts”.

• The count records individual vehicles by categories (i.e. a truck or car) and the direction they are travelling in. This is the reason it is called a ‘classified count’.

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Employs a field team to count and classify traffic volume.

Procedure No. of observers required depends upon no. of

Lanes and type of information required. More desirable to record traffic in each direction

of travel by posting separate observers for each direction.

For all-day counts ,work in three shifts can be arranged.

Data is recorded by Five- dash system. (IIII)

MANUAL METHOD BITS Edu C

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Equipments for manual counts

• Watch• clip board• Pencil, rubber, shapner• Data sheet


Manual Count Recording Methods

• Tally Sheets


Tally Sheets

• Recording data onto tally sheets is the simplest means of conducting manual counts. The data can be recorded with a tick mark on a pre-prepared field form. A watch or stopwatch is necessary to measure the desired count interval.


Survey Procedure


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Vehicle Type TallyCar

CNGBus

MotorcyclesNMT

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Details such as vehicle classification and no. of occupants can be obtained.

Records Turning movement data of vehicles at intersections.

Analyzing traffic characteristics in unusual conditions such as adverse weather conditions, traffic breakdowns, temporary closure of any lane of highway etc.

Comparatively cheaper method of counting.

Data accumulated by manual methods are easy to analyze.

MANUAL METHOD- ADVANTAGES BITS Edu C

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Not practicable to have manual count for 24 hrs of

the day and throughout the year.

Counts of remote areas is possible by automatic

devices.

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Automatic Counting Method


Automatic Counting MethodsAn automatic survey involves placing a tube or loop across a road

which is connected to a box containing the means for storing the information.

In this method, vehicles are counted automatically without any human involvement.

There are two techniques of automatic counting: a) Contact system based on pneumatic, mechanical, magnetic or

b)Contactless system based on electrical/optical, ultrasound/infrared radar, micro wave, CCTV/video image processing method etc.


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19Automatic Method

The automatic count method provides a means for gathering large amounts of traffic data. Automatic counts are usually taken in 1-hour intervals for each 24-hour period.

The counts may extend for a week, month, or year. When the counts are recorded for each 24-hour time period, the peak flow period can be identified.

Automatic counts are recorded using one of three methods: portable counters, permanent counters, and videotape

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20Automatic Method

Portable CountersPortable counting is a form of manual observation. Portable counters serve the same purpose as manual counts but with automatic counting equipment. The period of data collection using this method is usuallylonger than when using manual counts. The portable counter method is mainly used for 24-hour counts.Pneumatic road tubes are used to conduct this method of automatic counts Specific information pertaining to pneumatic road tubes can be found in the users’ manual.

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21Automatic Method

Permanent CountersPermanent counters are used when long-term counts are to be conducted. The counts could be performed every day for a year or more. The data collected may be used to monitor and evaluate trafficvolumes and trends over a long period of time.Videotape or VideographyObservers can record count data by videotaping traffic. Traffic volumes can be counted by viewing videotapes recorded with a camera at a collection site. A digital clock in the video image can prove useful in noting time intervals.

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Pneumatic road tube

Pneumatic road tube sensors send a burst of air pressure along a

rubber tube when a vehicle's tires pass over the tube.

Figure : Pneumatic Road Tube 23BITS Edu Campus Prof. Ankit Patel

Pneumatic Tubes


Bending plate

A weight pad attached to a metal plate embedded in the road to measure axel weight and speed. It is an expensive device and requires alteration to the road bed.

Figure : Bending Plate 25BITS Edu Campus Prof. Ankit Patel

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Equipments Used For Automatic Counting Method:

1.Pnematic Tubes 2. Weigh-In-Motion Sensor Types

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3. Vehicles counting by video camera (a) 3. Vehicles counting by video camera (b)


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4. Traffic counters


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7. Bending plate and pneumatic road tube 8. Automatic traffic recorders


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Factors affecting vehicle counting:

Weather conditions.Purpose of the traffic counting.Method of traffic counting.Location of the counting sites.Traffic flow level.Road type.Traffic composition.


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Traffic Flow Maps: Show volume along various routes by using bands

proportional to traffic volume carried. Thickness of lines represent traffic volume.

Intersection Flow Diagrams Give direction and volume of traffic through an

intersection.

Trend charts Shows the hourly , daily or monthly changes in

volume through an area. Useful for planning future expansion, design and

regulation.

PRESENTATION OF TRAFFIC VOLUME DATA BITS E

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Annual Average Daily Traffic(AADT)The total yearly volume divided by number of days in

the year. Average Daily Traffic(ADT)

The total volume during a given time period, in whole days greater than one day and less than one year, divided by number of days in that time period.

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33Passenger Car Unit

The different vehicle classes have a wide range of statics characteristics and dynamic characteristics, apart from these the driver behavior of the different vehicle classes is also found to vary considerable. Therefore mixed traffic flow characteristics are very much complex when compare to homogeneous traffic and it is difficult to estimate the traffic volume, capacity of roadway under the mixed traffic flow, unless the different vehicle classes are converted to one common standard vehicle unit.•Therefore it is a common practice to consider the passenger car as the standard vehicle unit to convert the other vehicle classes and this unit is called passenger car unit PCU.

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Passenger Car unit (PCU) :-

It is a common practice to consider the passenger car as the standard vehicle unit to convert the other vehicle classes and this unit is called Passenger car unit or PCU.

Thus in mixed traffic flow, the traffic volume & capacity are generally expressed as PCU per hour or PCU/lane/hour & the traffic density as PCU per kilometer length of lane.


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36Factor affecting Passenger Car

Unit Vehicle characteristics Speed distribution of the mixed traffic stream, volume to capacity

ratio. Roadway characteristics. Regulation and control of traffic. Environmental and climatic conditions.

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SPEED STUDIES

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Spot SpeedInstantaneous speed of a vehicle at a specified

location. Average Speed

Average of the spot speeds of all vehicles passing a given point on the highway.

Running SpeedAverage speed maintained by a vehicle over a

given course while the vehicle is in motion.Running speed= Length of course / Running

time = Length of course /( Journey time-

Delays)

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Journey speed Also known as overall travel speed It is the effective speed between two points. It is the

distance between two points divided by the total time taken by the vehicle to complete the journey ,including all delays.

Journey speed = Distance/ Total journey Time (including Delays).

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Speed and Delay Study


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The methods available for measuring spot speed can be grouped as

Those observations that require time taken by a vehicle to cover a known distance. It consist of long base methods- vehicles are timed over a long

distance. Short base methods- vehicles are timed over a Short

distance, say about 2m. Radar Speedometer which automatically records

instantaneous speed. Photographic method.

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I). Those observations that require time taken by a vehicle to cover a known distance.

Long base methods Direct timing Procedure Enoscope

a)Direct timing ProcedureSimplest methodTwo reference points are marked on the pavement at a suitable distance apart and an observer starts and stops stopwatch as a vehicle crosses these two marks.

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From known distance and time, speed can be calculated.

Disadvantage: errors due to parallax effect. Observation by two observers one at each

reference points First observer standing at the point in which the vehicle

pass first, signals and seconds observer starts the stop watch. The second observer stops the stop watch when he observes the same vehicle passing the reference point.

Disadvantage: reaction time of two observers.

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b). Enoscope Also known as mirror box L-shaped box, open at both ends ,with a

mirror set at 45 ˚ to the arms of the instrument.

ENOSCOPE BITS Edu C

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45˚

observer

vehicle

mirror

ENOSCOPE

It bends the line of sight of the observer perpendicular to the path of vehicle.

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ENOSCOPE BITS Edu C

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The instrument is placed directly opposite to the first reference point and the observer stations himself at the second reference point.

Stop watch is started as soon as the vehicle passes the first point and is stopped as soon as it passes the observer.

If two enoscope is used, the observer stations himself midway between two reference points.

Advantages: Eliminates parallax error. Equipment is of low cost, simple and can set up easily

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Works on the Doppler principle. Speed of a moving body is proportional to change in

frequency between the Radio wave transmitted to the moving body and the radio wave received back.

Instrument directly measures speed. Instrument is setup near the edge of carriageway at

a height of 1m.

The speed meter is so kept that the angle between direction of travel of vehicle and axis of transmission of radio wave is as low as possible, say within 20˚.

Speed of vehicles in both directions can be observed.

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Time-lapse camera photography can be used. Photographs are taken at fixed intervals of

time(say one second per frame) on a special camera.

By projecting the film on a screen, the passage of any vehicle can be traced with reference to time.

Images by video cameras can be also used.

PHOTOGRAPHIC METHOD BITS Edu C

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Data collection formBITS Edu Campus Prof. Ankit Patel 52

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Average speed of vehiclesFrom spot speed data, distribution tables are

prepared by arranging the data in groups covering various speed ranges and number of vehicles in each range.

Arithmetic mean is the average speed.

Cumulative speed of vehiclesGraph is plotted with average values of each group

on X-axis and cumulative % of vehicles travelling at different speeds.

PRESENTATION OF SPOT SPEED DATA

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85th percentile speed: Speed at or below 85 % of vehicles are passing the point of highway.

Only 15 % of vehicles exceed the speed at that spot.

Drivers exceeding 85th percentile speed are considered to drive faster than the safe speed. Hence 85th percentile speed is adopted for Safe speed limit at that zone.

50th percentile speed: median speed.

15th percentile speed: represents the lower speed limit.

PRESENTATION OF SPOT SPEED DATA (contd..)

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Speed and Delay Study• Speed and delay studies give running speeds, overall

speeds, fluctuations in speed and delay between two stations of a road spaced far apart. They also give the information such as amount, location, duration, frequency and causes of the delay in the traffic stream. Various methods to carry out speed and delay survey are:

• Floating Car method• Licence Plate record method• By Interview• By Photography and videography


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61Methods of Speed and Delay

StudyLicense Plate Method: it synchronized stop watches or voice recording equipment are used. Observers are stationed at the entrance and exit of a test section where information of travel time is required. The timings and vehicle numbers are noted by the observers of the selected sample. From the office computations , travel time of each vehicle could be found. But the method does not give important detail such as causes of delays and the duration and number of delays within the test section.

Interview Technique: The work can be completed in a short time by interviewing and collecting details from the road user spot. However the data collected may not provide with all the details correctly.

Elevated observation and photographic technique: this are useful for studying short test section like intersection. BITS Edu

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ORIGIN AND DESTINATION

STUDY

In a transportation study, it is often necessary to know the exact origin and destination of the trips. The information yielded by O-D survey includes land-use of the zones of origin and destination, household characteristics of the trip making family, time of the day when journeys are made, trip purpose and mode of travel.

INTRODUCTION

Origin is defined as the place where the trip begins and destination is defined as the place where the trip ends.

Origin-Destination (OD) studies are an important tool for transportation Professionals. OD studies are conducted to understand the pattern of the movement of Persons and goods in a particular area of interest during a particular period of time (Wang, 1997).

O & D SURVEY

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THE ORIGIN AND DESTINATION STUDY IS CARRIED OUT MAINLY TO KNOW THE ORIGIN AND DESTINATION OF VARIOUS VEHICALS .

IN THIS STUDY THE DATA COLLECTED ARE, NUMBER OF VEHICLES, THEIR ORIGIN AND DESTINATION NUMBER OF PASSENGERS IN EACH VEHICLE,ROUTE ETC.

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USE FOR O & D SURVEY

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TO ESTABLISH PREFERENTIAL ROUTES FOR VARIOUS CATEGORIES OF VEHICLES

TO LOCATION OF NEW PROPOSED ROADSTO LOCATION OF PARKING PALACESTO LOCATE EXPRESSWAYTO REGULATE MOVEMENT OF HEAVY

VEHICLESTO LOCATE NEW BRIDGE AS PER TRAFFIC

DEMANDS

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METHOD OF O & D SURVEY

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ROAD SIDE INTERVIEW SURVEYSHOME-INTERVIEW SURVEYSTELEPHONE SURVEYSTAXI SURVEYSPOST CARD QUESTIONNAIRE SURVEYSREGISTRATION NUMBER SURVEYTAG SURVEYPUBLIC TRANSPORT SURVEYCOMMERCIAL VEHICAL SURVEY

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ROAD SIDE INTERVIEW SURVEY

IN THIS METHOD INTERVIEW STATIONS ARE PREVIOUSLY DECISED ON THE ROADWAY.

THE VEHICLES ARE STOPPED AT THE INTERVIEW STATIONS BY A GROUP OF PERSONS AND THE ANSWERS TO PRESCRIBED QUESTIONNAIRE ARE COLLECETED ON THE SPOT.

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INFORMATION COLLECTED

•PLACE AND TIME OF ORIGIN

•PLACE AND TIME OF DESTINATION

•ROUTE

•PURPOSE OF THE TRIP

•TYPES OF VEHICLES

•NUMBER OF PASSENGERS IN EACH VEHICLE

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ROAD SIDE INTERVIEW SURVEY

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Survey Questionnaire:Location:Date:STANDARD FORMAT Origin-Destination SurveyQuestionsPlease take a moment to answer a few questionsabout your trip. Your responses will help determine theneed for improvements in this area.·Where did your trip begin?City/Town _____________________________State ______Zip _______·What type of place is your trip start point?

❒ Primary Residence ❒ Workplace ❒ Store ❒ School (I am a student) ❒ Recreation Area

❒Other _________________________________

·Where did your trip end?City/Town _____________________________State ______Zip __________·What type of place is your trip end point?

❒ Primary Residence ❒ Workplace ❒ Store ❒ School (I am a student) ❒ Recreation Area ❒ Other _________________________________

·What was the purpose of your trip? ❒ Work Commute ❒ Business Related ❒ Shopping ❒ School (attend class)

❒Recreation ❒Other ___________________·How many people were in the vehicle, includingthe driver?

❒ 1 ❒ 2 ❒ 3 ❒ 4 ❒ 5 orMore

·What type of vehicle were you in? ❒ Passenger vehicle (car,

motorcycle,SUV, pick-up truck, minivan)

❒ Commercial vehicle❒Other____________________________·Do you regularly use this route?

❒ Yes ❒ No

·Please add any comments on transportation youMay have.Comments____________________________Thank you very much for your cooperation!

ADVANTAGES & DISADVANTAGES

ADVANTAGES :DATA IS COLLECTED QUICKLY IN SHORT

DURATION

DISADVANTAGES:THE VEHICLES ARE STOPPED FOR

INTERVIEW AND THERE IS DELAY TO THE VEHICULAR MOVEMENT

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HOME-INTERVIEW SURVEY

IN THIS METHOD RANDOM SAMPLE OF 0.5 TO 10% OF THE POPULATION IS SELECTED AND THE RESIDENCE ARE VISITED BY THE TRAINED PERSON WHO COLLECT THE TRAVEL DATA FROM EACH MEMBOR OF THE HOUSEHOLD.

DETAILD INFORMATION REGARDIND THE TRIPS MADE BY THE MEMBERS IS OBTAINED ON THE SPOT.

THE DATA COLLECTED MAY BE USEFUL EITHER FOR PLANNING THE ROAD NETWORK AND OTHER ROADWAY FACILITIES.

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HOME INTERVIEW SURVEY

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DATA COLLECTION

NUMBER OF TRIP MADETHEIR ORIGIN & DESTINATIONPURPASE OF TRIPTRAVEL MODENUMBER OF RESIDENTSAGEVEHICLE OWNERSHIPNUMBER OF DRIVERSFAMILY INCOME

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ADVANTAGES & DISADVANTAGES

ADVANTAGES:THE PROBLEM OF STOPPING OF VEHICLES

AND CONSEQUENT DIFFICULTIES ARE AVOIDED

THE PRESENT TRAVEL NEEDS ARE CLEARLY KNOWN AND THE ANALYSIS IS ALSO SIMPLE.

ADDITIONAL DATA INCLUDING SOCIO-ECONOMIC AND OTHER DETAILS MAY BE COLLECTED SO AS TO BE USEFUL FOR FORECASTING TRAFFIC AND TRANSPORTATION GROWTH.Prof. Ankit Patel

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TELEPHONE SURVEY

THIS METHOD INTERVIEW ARE CONDUCT WITH COMPUTER ASSISTED TELEPHONE INTERVIEW TECHNOLOGY.

A COMPLETE CATI SYSTEM MIGHT INCLUD AUTOMATIC DAILING OF NEXT HOUSEHOLD TO THE INTERVIEWER TO ASK THE NEST QUESTION AUTOMATIC SKIPPING AND BRANCHING WITHIN THE LIST OF QUESTIONS DEPENDING ON THE ANSER TO THE PREVIOUS QUESTION ,IMMEDIATE LOGIC CHECKS ON ANSWER PROVIDED.Prof. Ankit Patel

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TELEPHONE SURVEY

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ADVANTAGES:SAVING THE TIME DISADVANTAGES:INFORMATION RESPONCE NOT GOOD

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TELEPHONE SURVEY

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TAXI SURVEY

LARGE URBAN AREAS USUALLY HAVE A SIZEABLE AMOUNT OF TRAVEL BY TAXIS.

IN SUCH CASES, A SEPARATE TAXI SURVEY IS NECESSARY .

THE SURVEY CONSISTS OF ISSUING QUESTIONNAIRES OR LOG SHEETS TO THE TAXI DRIVERS AND REQUESTING THEM TO COMPLETE THE SAME.

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TAXI SURVEY

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POST CARD

IN THIS METHOD REPLY-PAID QUESTIONNAIRES ARE HANDED OVER TO EACH OF THE DRIVERS AT THE SURVEY POINTS AND REQUISTING THEM TO COMPLETE THE INFORMATION AND RETURN BY POST.

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ADVANTAGES:THIS METHOD ARE SIMPLER AND

CHEAPER THAN MANY OTHERS.

DISADVANTAGES:RESPONSE MAY NOT A GOOD

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POST CARD

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REGISTRATION NUMBER PLATE SURVEY

REGISTRATION NUMBER PLATE SURVEY CONSISTS OF NOTING THE REGISTRATION NUMBER OF VEHICLES ENTERING OR LEAVING AN AREA AT SURVEY POINTS LOCATED ON THE CORDON LINE.

BY MATCHING THE REGISTRATION NUMBER OF THE VEHICLES AT THE POINT OF ENTRY AND EXITFROM THE AREA , ONE IS ENABLED TO IDENTIFY TWO POINTS ON THE PATHS OF THE VEHICLES.

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ADVANTAGES:WORK DOES NOT INTERFERE WITH THE

TRAFFIC IN ANY WAY.

DISADVANTAGES:LARGE NUMBER OF OBSERVERS ARE

NEEDED ANALYSIS OF THE RESULTS CAN BE

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TAG SURVEY

IN THIS METHOD AT EACH POINT WHERE THE ROADS CROSS THE CORDON LINE, VEHICLES ARE STOPPED AND A TAG IS AFFIXED ,USUALLY UNDER A WIND SCREEN WIPER.

THE TAGS FOR DIFFERENT SURVEYS STATIONS HAVE DIFFERENT SHAPES/COLOUR TO IDENTIFY THE SURVEY STATION.

THE VEEHICLES ARE STOPPED AGAIN AT THE EXIT POINTS WHERE THE TAGS ARE REMOVED.

THE TIME OF ENTERING AND LEAVING THE AREA MAY BE MARKED ON THE TAGS IN ORDER TO ENABLE THE JOURNEY TIME TO BE DETERMINED

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ADVANTAGES:THIS METHOD IS SIMPLE AND ERROR ARE

NOT VERY LARGE.

DISADVANTAGES:IT IS NOT POSSIBLE TO HANDLE ALL THE

VEHICLES, SAMPLING MAY BE RESTORED TO DONE.

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TAG SURVEY

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PUBLIC TRANSPORT SURVEYS

IN THIS METHOD INTERVIWER MAY ENTER THE VEHICLE AND CARRY OUT THE INTERVIEWS WHEN THE VEHICLES IS IN MOTION.

POST-CARD QUESTIONNAIRES ELIMINATE DELAYS, BUT ARE LIKELY TO EVOKE POOR RESPONSE OR CONTAIN AN ELEMENT OR BIAS.

THESE QUESTIONNAIRES MAY ALSO BE COLLECTED AT THE STATIONS INSIDE THE SURVEY AREA.

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PUBLIC TRANSPORT SURVEYS

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COMMERCIAL VEHICAL SURVEYS

COMMERCIAL VEHICLE SURVEYS ARE CONDUCTED TO OBTAIN INFORMATION ON JOURNEYS MADE BY ALL COMMERCIAL VEHICLES BASED WITHIN THE STUDY AREA.

THE ADDRESSES OF THE VEHICLES OPERATORS ARE OBTAINED AND THEY ARE CONTACTED .

FORM ARE ISSUED TO DRIVERS WITH A REQUEST THAT THEY RECORD PARTICULARS OF ALL THE TRIPS THEY WOULD MAKE.Prof. Ankit Patel

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COMMERCIAL VEHICAL SURVEYS

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PARKING STUDY

Introduction

One of the problems created by road traffic is parking. Not only do

vehicles require street space to move about, but also do they require

space to park where the occupants can be loaded and unloaded. The

period over which a car is parked is very great compared with the time it

is in motion. Every car owner would wish to park the car as closely as

possible to his destination so as to minimize his walking.

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Introduction Traveling vehicles at one time or another will

need to park for short or long times. Need for parking spaces is great in areas where

land uses include (business, residential, or commercial).

In high density areas spaces are very expensive, thus the space provided for automobiles usually has to be divided between their movement and parking.


Effect of parking

Congestion Accidents Obstruction to fire fighting operations Effect on environment

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981. Congestion: Parking takes considerable street space leading to the lowering of the road capacity. Hence, speed will be reduced, journey time and delay will also subsequently increase. The operational cost of the vehicle increases leading to great economical loss to the community.2. Accidents: Careless maneuvering of parking and unparking leads to accidents which are referred to as parking accidents. Common type of parking accidents occur while driving out a car from the parking area, careless opening of the doors of parked cars, and while bringing in the vehicle to the parking lot for parking.

ILL EFFECT OF PARKING

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993. Environmental pollution: They also cause pollution to the environment because stopping and starting of vehicles while parking and unparking results in noise and fumes. They also affect the aesthetic beauty of the buildings because cars parked at every available space creates a feeling that building rises from a plinth of cars.4. Obstruction to fire fighting operations: Parked vehicles may obstruct the movement of firefighting vehicles. Sometimes they block access to hydrants and access to buildings.

ILL EFFECT OF PARKING

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General Terms of Parking Facilities

Parking Accumulation :-The total number of vehicles parked in an area at a specified moment.

Parking volume:-The number of vehicles parked in a particular area over a given period of time. It is usually measured in vehicles per day. This does not account for repetition of vehicles. The actual volume of vehicles entered in the area is recorded.

Parking load:-Parking load gives the area under the accumulation curve. It can also be obtained by simply multiplying the number of vehicles occupying the parking area at each time interval with the time interval. It is expressed as vehicle hours.

Parking duration:-The length of time spent in a parking space. Parking turn over:-It is the ratio of number of vehicles parked in a

duration to the number of parking bays available. This can be expressed as number of vehicles per bay per time duration.

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Parking system

On street parking:On street parking means the vehicles are parked on the sides of the street itself. This will be usually controlled by government agencies itself. Common types of on-street parking are as listed below. This classification is based on the angle in which the vehicles are parked with respect to the road alignment. As per IRC the standard dimensions of a car is taken as 5× 2.5 meters and that for a truck is 3.75× 7.5 meters.1. Parallel parking: The vehicles are parked along the length of the road. Here there is no backward movement involved while parking or unparking the vehicle. Hence, it is the most safest parking from the accident perspective.

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Parking system2. 30◦ parking: In thirty degree parking, the vehicles are parked at 30◦ with respect to the road alignment. In this case, more vehicles can be parked compared to parallel parking. Delay caused to the traffic is also minimum in this type of parking.3. 45◦ parking: As the angle of parking increases, more number of vehicles can be parked. Hence compared to parallel parking and thirty degree parking, more number of vehicles can be accommodated in this type of parking.4. 60◦ parking: The vehicles are parked at 60◦ to the direction of road. More number of vehicles can be accommodated in this parking type.5. Right angle parking: In right angle parking or 90◦ parking, the vehicles are parked perpendicular to the direction of the road. Although it consumes maximum width kerb length required is very little. In this type of parking, the vehicles need complex maneuvering and this may cause severe accidents. This arrangement causes obstruction to the road traffic particularly if the road width is less.

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On – street or Kerb Parking

1. Parallel Parking

2. 30 degree parking

3. 45 degree parking

4. 60 degree Parking

5. 90 degree ParkingBITS Edu


Parallel Parking

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30 degree parking

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45 degree parking

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60 degree Parking

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90 degree Parking

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Parking systemOff street parking In many urban centers, some areas are exclusively allotted for parking which will be at some distance away from the main stream of traffic. Such a parking is referred to as off-street parking.

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Parking surveyIn-out surveyIn this survey, the occupancy count in the selected parking lot is taken at the beginning. Then the number of vehicles that enter the parking lot for a particular time interval is counted. The number of vehicles that leave the parking lot is also taken. The final occupancy in the parkinglot is also taken. Here the labor required is very less. Only one person may be enough. But we wont get any data regarding the time duration for which a particular vehicle used that parking lot. Parking duration and turn over is not obtained. Hence we cannot estimate the parkingfare from this survey. For quick survey purposes, a fixed period sampling can also be done. This is almost similar to in-out survey. All vehicles are counted at the beginning of the survey. Then after a fixed time interval that may vary between 15 minutes to i hour, the count is again taken. Here there are chances of missing the number of vehicles that were parked for a short duration.

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Prof. Ankit Patel

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Parking surveyLicense plate method of surveyThis results in the most accurate and realistic data. In this case of survey, every parking stall is monitored at a continuous interval of 15 minutes or so and the license plate number is noted down. This will give the data regarding the duration for which a particular vehicle was using the parking bay. This will help in calculating the fare because fare is estimated based on the duration for which the vehicle was parked. If the time interval is shorter, then there are less chances of missing short-term parkers. But this method is very labor intensive.

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ACCIDENT STUDY

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Parking survey

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Prof. Ankit Patel

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ACCIDENT STUDYCauses of road accidents1. Road Users - Excessive speed and rash driving, violation of traffic rules, failure to per-ceive traffic situation or sign or signal in adequate time, carelessness, fatigue, alcohol, sleep etc.2. Vehicle - Defects such as failure of brakes, steering system, tyre burst, lighting system .3. Road Condition - Skidding road surface, pot holes, ruts.4. Road design - Defective geometric design like inadequate sight distance, inadequate width of shoulders, improper curve design, improper traffic control devices and improper lighting.5. Environmental factors -unfavorable weather conditions like mist, snow, smoke and heavy rainfall which restrict normal visibility and and makes driving unsafe.6. Other causes -improper location of advertisement boards, gate of level crossing not closed when required etc.. BITS Edu

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Prof. Ankit Patel

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ACCIDENT STUDYCollision Diagrams Collision diagrams are used to display and identify similar accident patterns. They provide information on the type and number of accidents; including conditions such as time of day, day of week, climatic conditions, pavement conditions, and other information critical to determining the causes of safety problems. Accident reports should be organized by year of occurrence and accident type for the analysis period. Accidents that occurred after significant changes in highway or local land use should not be included.

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Prof. Ankit Patel

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ACCIDENT STUDYA. Construction of Collision Diagram Sketch of the collision diagram for either an intersection or a roadway section using a standard form as shown on the following page. 1. The sketch need not be to scale. 2. Show the path of each vehicle involved in the accident with adequate room for information. 3. Place a north arrow for orientation and any other descriptive information: a) Location identification b) Period of analysis c) Label the roads

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Prof. Ankit Patel

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ACCIDENT STUDY4. Sketch the path of each vehicle to show vehicle manoeuvre, type of collision and accident severity, and; a) Time of day b) Day of week c) Date d) Lighting condition e) Pavement condition f) Other important information, e.g., alcohol involvement B. Symbols

Symbols representing the nature of operation, vehicle or object involved and severity of the accident are adopted. These are shown in the example collision diagram below. Symbols to represent types of collisions diagrams are also standardized.

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Prof. Ankit Patel

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ACCIDENT STUDY

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Prof. Ankit Patel

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ACCIDENT STUDYCondition Diagrams: The purpose of the Condition Diagram is to show the intersection and the conditions within the surrounding area as it exists. The diagram should include the intersection alignment, items such as buildings, sidewalks, trees, lighting poles, water hydrants, stop signs, number of lanes, and lane use if required, associated with the streets forming the intersection. When applicable, the Condition Diagram shall show the length of all exclusive lanes.The Condition Diagram provides the engineer with details of field conditions and helps investigate the need for changes to existing traffic control devices. The diagram should also be part of an intersection crash analysis.

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Prof. Ankit Patel

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ACCIDENT STUDYPreparing the Condition Diagram A. General Details 1. The engineer should enter the Location I.D. so that the intersection is thoroughly identified. 2. The name of the highway, highway number, and direction for both streets should be included. 3. County, City, Date, and Person(s) preparing the diagram. 4. Orient the intersection by indicating north on the north arrow. All items associated with the streets should be drawn using the symbols as outlined on the bottom of the form.

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Prof. Ankit Patel

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ACCIDENT STUDYB. Highway and intersection design features, including: a) Pavement edges, curbs, and shoulders (unpaved or paved) b) Widths of approaches c) Approach grades d) Channelization e) Parking conditions and restrictions f) Bus stops g) Safety lighting or continuous lighting h) Any other roadway features which may affect traffic operations

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ACCIDENT STUDYC. Roadside development, including: a) Sight distance restrictions (trees, bushes, advertising and other signs, poles, fences, bridge, and guard rails) b) Off street parking c) Driveway locations d) Utility and other poles e) Adjacent land use f) Any other pertinent features D. Traffic control devices, such as: a) Signs b) Traffic signals (type, face locations, etc.) c) Distance to adjacent traffic signals within 1.61 km (one mile) (indicate if none) d) Pavement markings

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ACCIDENT STUDY

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PREVENTION OF ROAD ACCIDENT

Strict punishment should be enforced by govt. if a person drives in over speed

Tamper proof speed controllers should be installed in all vehicles.

Two wheelers should not exceeded 50-70km/h.

All the rules should be followed properly by the people.

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THANK YOU

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