Speed and Delay Study on National Highway

CENTRAL ROAD RESEARCH INSTITUTE, NEW DELHI

2011

SPEED AND DELAY STUDY

ON NATIONAL HIGHWAY-2 ASSIGNMENT REPORT

Ashutosh Arun (AA 2010 02)

Gagandeep Singh (GS 2010 04)

PGRPE-2010

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SPEED AND DELAY STUDY ON NATIONAL HIGHWAY 2 – ARUN & SINGH

Speed and Delay Study on National Highway-2

Ashutosh Arun (AA 2010 02)

Gagandeep Singh (GS 2010 04)

QHS-Trainees

Central Road Research Institute

EXECUTIVE SUMMARY

This report is a result of the findings by the authors regarding the speeds and delays

encountered by the vehicles plying on NH-2, also called Mathura Road. This work

was undertaken as a field assignment in conjunction with authors’ ongoing class

room training as a part of their course work for the degree of Masters of Technology.

The section considered for study includes the stretch between Ashram intersection

and the intersection just in front of CRRI in both the directions. In order to accurately

reflect the traffic conditions at all times of day, speed and delay study was conducted

on 25th February, 2011 for off-peak hours from around 11 am to 1 pm and on 3rd

March, 2011 for peak hours starting from around 8.15 am to 9.30 am. The method

adopted for the study was the Floating Car Method as it was considered to be the

most convenient and comprehensive method for this purpose.

The first chapter in the report deals with general introduction about the survey

philosophy and techniques thereof.

The results of the study have been represented in both tabular and graphical form

and have been extensively analysed, with the discussions included in the second

chapter.

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INTRODUCTION

With the rapid increase in population, urbanization and income levels in India, the

number of motor vehicles on the Indian roads is drastically increasing with every

passing day. Alas, the same cannot be said about the roads that are required to

carry these vehicles!

A look at the data provides the insight required to appreciate the problem.

It can be seen from the above table1, the concentration of automobiles (22 percent)

is in eight urban areas. Delhi is having total registered vehicles of more than 3.5

million (2002) with the predominance of two wheelers and cars, used as private

passenger vehicles.

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The corresponding traffic volumes plying on the roads of Delhi have also seen a

humongous increase as can be seen from the following table1.

But the statistics available about the roads in Delhi carrying such high volumes of

traffic cannot be called very encouraging. The following table2 makes this

discrepancy clear.

DELHI ROADS BY AREA & POPULATION (in Kilometres)

Item 1993-94 1994-95 1995-96 1996-97 Total length of

road 24628 24645 25948 25949

Average Length of road per 100

sq. Km.

1661 1662 1749 1749

Road length per 1000 population

2.35 2.27 2.21 2.15

Road length per 1000 vehicles.

10.99 10.13 9.87 9.11

Source: Delhi Statistical Hand Book - 1998, Dte. of Eco. & Stat., Government of NCT of Delhi.

Thus while there is a marginal increase in the road length per 100 sq.Km., there has

been a steady decline noticeable in available road length per 1000 population as well

vehicles.

A direct effect of such a discrepancy is the increase in travel time due to delays

caused by congestion, long queues of vehicles at intersections and such reasons

which also cause significant reduction in the travel speeds of the vehicles. This

impacts the Level of Service of a road as well as the Road User Cost.

In order to be able to better appreciate the speed and delay characteristics of

Mathura Road, the authors carried out a speed and delay survey of a section of the

road the results of which have been subsequently discussed.

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CHAPTER 1: SPEED AND DELAY STUDY- IN GENERAL

The speed and delay studies give the running speeds, journey speeds, fluctuations

in speeds and delay between two stations on a road. They also give the information

such as the amount, location, frequency and causes of the delay in the traffic stream.

The results of the speed and delay studies are useful in detecting the spots of

congestion, the causes and in arriving at a suitable remedial measure. The studies

are also utilized in finding the travel time between the two stations and the benefit-

cost analysis. In general, the efficiency of a roadway can be judged from the travel

time.

The delay or the time lost by traffic during the travel period may be either due to fixed

delays or operational delays. Fixed delays occur primarily at intersections due to

traffic signals and at level crossings of railways. Operational delays are caused by

the interference of traffic movements such as turning vehicles, parking and vehicles

joining the traffic stream after parking, pedestrians etc. and also due to high traffic

volume, inadequate capacity of the road and accidents. Therefore the overall journey

speed between the origin and destination of travel is always lower than the desired

running speed.

METHODS OF STUDY

There are various methods of carrying out speed and delay study, namely;

Floating car method

License plate or registration number method

Interview technique

Elevated observations

Photographic technique

In floating car method, a test vehicle is driven over a given course of travel at

approximately the average speed of the stream, thus trying to float with the traffic

stream. A number of test runs are made along the study stretch and a group of

observers record the various details. Two observers are required with two stop

watches. One of the stop watches is continuously operated and is required to find

out the travel time between two nodes or control points along the stretch. These

control points are fixed beforehand and include any fixed point such as intersections,

bridges etc. The other stop watch is used to find the duration of individual delays.

One of the observers, records the duration, location and cause of these delays as

well as the overall travel time between two nodes either on suitable tabular forms or

by voice recording instruments.

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In the license plate or registration number method, synchronized stop watches

are used. Observers are stationed at the entrance and exit of the test section. The

timings and the registration numbers of the vehicles are recorded by the observers of

the selected sample. From the office computations, travel time of each vehicle can

be found. But the method does not give important details such as causes of delays

and the duration and frequency of individual delays within the test section.

In the interview technique, work can be completed within a very short span of time

by interviewing and collecting details from the road users on the spot. However, the

data collected may not provide accurate details.

Elevated observations and photographic techniques are useful for studying short

test sections like intersections etc.

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CHAPTER 2: PRESENT STUDY DETAILS

SECTION FOR STUDY

The section considered for study is the one between Ashram intersection and CRRI

intersection. Since it is a dual carriageway, thus both the directions of travel were

considered. The total length of the test section is 2.83 Km.

METHOD OF STUDY

The method adopted for study was floating car method. From the discussion in

previous chapter it can be seen that this method has a distinct advantage over other

methods is that it is most suitable for long test sections and can provide details about

the individual delays occurring within the test section.

For the purpose of survey, the test section was divided into four sub-sections with

their boundaries clearly defined by five control points or nodes fixed along the route.

Thereafter, the nodal distances i.e. the lengths of the sub-sections were measured

using a measuring wheel. These sub-sections, nodes and the corresponding nodal

distances are listed in the table below:-

Sub-section From Node To Node Nodal Distance

CRRI-Kalka Mod CRRI (Traffic Signal

Post 1)

Kalka Mod (Centre line of the flyover

2)

810.3 m

Kalka Mod-New Friends Colony Intersection

Kalka Mod (Centre

line of the flyover 2) New Friends Colony (Traffic

Signal Post 3)

460.3 m

New Friends Colony-Mata Ka Mandir Intersection

New Friends Colony (Traffic Signal Post

3)

Mata Ka Mandir (Traffic Signal Post

4)

445.1 m

Mata Ka Mandir Intersection-Ashram Intersection

Mata Ka Mandir (Traffic Signal Post

4)

Ashram (Traffic

Signal Post 5) 1116.6 m

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These nodes are also pictorially represented below for better understanding of their

locations:-

TIME FOR STUDY

It has been generally seen that on Mathura Road the morning peak hour of traffic

starts around 8:15 am and continues up to around 10:00 am. This is followed by an

intermediate peak hour which starts around 12:30 pm and continues up to around

2:30 pm after which the evening peak hour starts around 5:15 pm and continues up

to 7:30 to 8:00 pm and sometimes even later. These peak hours are separated in

between by certain off-peak hours marked by lean flow values of traffic.

The objective of this study was to have the speed and delay values on Mathura

Road for the morning peak hour and the following off-peak hour. Since, due to

limitation of man-power, the studies for both the periods were not possible on a

single day. Hence the complete study was conveniently divided into two phases. In

phase 1, off-peak hour speed and delay survey of the section was to be conducted

from around 11 am to be continued till around 1 pm when the intermediate peak flow

starts building up. The phase 2 was to include the peak hour survey to be conducted

between around 8:15 am and 10:00 am.

The dates decided for the phases 1 and 2 of the survey were 25 th February, 2011

and 3rd March, 2011 respectively.

OBSERVATIONS

An example of the survey sheet prepared and used for recording the observations is

attached with this report.

An important precaution taken while conducting the survey was to ensure that the

vehicle was actually ‘floating’ with the traffic. The problem arose because as seen in

the map below (the callout with 1 written in it), the node 1 i.e. the traffic signal post in

front of CRRI and the gap in median for taking the turn are just at the opening of the

main gate of CRRI.

1 2 4 3 5

CRRI GATE

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Because of this, whenever the signal turned green allowing the vehicles standing

and waiting at the main gate to take the right turn and come on to the highway, it was

the red phase for the straight movement. Thus in effect the survey vehicle would get

ahead of the traffic stooped at the signal which allowed the vehicle to be driven at

any desired speed and hence it would not be able to mimic the speed of the traffic

stream. Similar problem was present at the other end of the section at Ashram

intersection. There a U-turn taken in order to perform the return trip towards CRRI

would put the vehicle again ahead of the traffic.

In order to negate this, the lengths of the run were increased and the intersections

next to the end-intersections considered were decided to be utilized for taking the U-

turns. Thus the trip ends were actually shifted to Apollo and Bhogal intersections

respectively instead of CRRI and Ashram, though the observations were begun to be

recorded only when the observer physically crossed the designated nodes. This

would put the vehicle in the stream of vehicles and hence it would better be able to

mimic the characteristics of the stream.

After observing the readings, they were fed into computer and analyzed with the help

of MS Excel. A filled excel observation sheet has also been attached with the report.

1

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RESULTS AND DISCUSSIONS

The final results of the study have been shown below:-

PEAK HOUR

Direction of Travel: Ashram to CRRI (D1)

Time of Day Travel Time (s) Avg. Journey

Speed (kmph)

Avg. Running Speed (kmph)

Total Delay

(s)

8:20 AM 759.99 13.4 19.2 229.6

8:53 AM 861.89 11.8 17.7 287.2

9:31 AM 587.89 17.3 25.4 186.5

Direction of Travel: CRRI to Ashram (D2)


Speed (kmph)


Total Delay

(s)

8:15 AM 288.17 35.4 39.3 28.9

8:43 AM 325.24 31.4 41.6 80.2

9:20 AM 334.83 30.5 42.0 92.3

Basic Statistics:


Travel Time (s) Avg. Journey Speed (kmph)


Total Delay (s)

Mean 736.59 Mean 14.20 Mean 20.79 Mean 234.42

Median 759.99 Median 13.42 Median 19.22 Median 229.55

Standard Deviation

138.49 Standard Deviation



50.50

Range 274.00 Range 5.51 Range 7.66 Range 100.64

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Travel Time (s) Avg. Journey Speed (kmph)


Total Delay (s)



Standard Deviation




33.66


Graphically the data have been represented below.


0.0

5.0

10.0

15.0

20.0

25.0

30.0

8:09 AM 8:24 AM 8:38 AM 8:52 AM 9:07 AM 9:21 AM 9:36 AM

0.0

100.0

200.0

300.0

400.0

500.0

600.0

700.0

800.0

900.0

1000.0

8:09 AM 8:24 AM 8:38 AM 8:52 AM 9:07 AM 9:21 AM 9:36 AM

Spee

d (

kmp

h)

Del

ay (

s)

Average

Running Speed

Average Journey

Speed

Travel Time

Total Delay

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The inferences that can be drawn from the above results are as below:

The morning peak hour volume of traffic starts building sometime around 8:30

am in both the directions. The paucity of data points renders prediction about

the end of peak hour inconclusive.

The average travel time during the peak hour in D1 direction is 12 mins 40

secs while that in D2 direction is just 5 mins 25 secs (median values). This

indicates that the congestion is more in the D1 direction as compared to D2.

There are large differences in the deviations about means in values of travel

times in both the directions. The standard deviation for D1 direction (138.5

secs) is 82% larger than that in D2 direction (24.6 secs).

In the direction D1, the average journey and running speeds follow similar

distribution and an increase in total delay causes decrease in both the

20.0

25.0

30.0

35.0

40.0

45.0

8:09 AM 8:38 AM 9:07 AM 9:36 AM

0.0

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

8:09 AM 8:24 AM 8:38 AM 8:52 AM 9:07 AM 9:21 AM 9:36 AM

Spee

d (

kmp

h)

Del

ay (

s)

Average

Running Speed

Average Journey

Speed

Travel Time

Total Delay

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speeds. However, the trend is very different in the other direction D2. Here an

increase in delay causes a decrease in the journey speed but the running

speeds can be found to be increasing. This is because the vehicles tend to

accelerate between two consecutive points of delay (mainly the mid-block

sections between a consecutive pair of intersections) in order to make up for

the increase in travel time occurring due to delay.

The average journey speed (median value 13.42 kmph) and correspondingly

the average running speed (median value 19.22 kmph) in D1 direction are

very low when compared to the allowable speed of 60 kmph for cars on the

section during peak hour.

The average journey speed (median value 31.35 kmph) and the average

running speed (median value 41.61 kmph) in D2 direction are still lower when

compared to the allowable speed of 60 kmph for cars on the section during

peak hour but significantly better than the other direction.

The journey and running speeds in D1 direction are respectively 57% and

54% lower than the journey and running speeds in D2 direction, when the

median values are compared.

The total delays from Ashram towards CRRI are 65% larger than that in the

opposite direction, when the median values are compared.

There are larger variations in the average running speeds in the direction D1

(SD 4.06 kmph) when compared to those in D2 direction (SD 1.46 kmph).

The above three points corroborate the fact that congestion as experienced in

the D1 direction is much severe when compared to the other direction. This

may be the result of higher traffic volumes and more turning movements

associated with this particular direction.

The bottleneck portions identified in both the directions with respective major

causes of delay are given in the table below:


Sub-Section Maximum Delay (s) Cause of Delay

Ashram - Mata Ka Mandir 171.6 Red Signal, RT traffic and Queuing of vehicles at the

Mata Ka Mandir intersection which takes a long time to

clear. Also the buses stopping at the Ashram bus stop tend to stop almost in the mid lane because of

insufficient opportunity for lane changing and

unwillingness.

Mata Ka Mandir - NFC 11.9 Only due to red signal at NFC intersection.

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NFC – Kalka Mod 139.8 Due to the traffic merging from the off-ramp of the

Kalkaji flyover and pedestrians crossing the

road at that place.

Kalka Mod - CRRI 205.1 Multiple Reasons: Buses stopping in almost mid lane

at Sukhdev Vihar Depot stop, a broken down truck, red signal, U-turning traffic

waiting for appropriate signal occupying one lane, queuing

of vehicles.



CRRI – Kalka Mod 0 -

Kalka Mod - NFC 6 Traffic merging from the off-ramp of the Kalkaji

flyover and traffic turning right towards NFC district

centre.

NFC – Mata Ka Mandir 80.2 Red Signal

Mata Ka Mandir - Ashram 28.9 Red Signal

OFF-PEAK HOUR

Direction of Travel:

Ashram to CRRI (D1)


Speed (kmph)


Total Delay (s)

11:05 AM 430.2 23.7 26.5 45.8

11:24 AM 536.2 19.0 24.2 115.5

12:04 PM 541.2 18.8 30.3 205.0

12:40 PM 678.3 15.0 26.6 294.6

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Direction of Travel:

CRRI to Ashram (D2)

Time of Day Travel Time

(Secs) Avg. Journey

Speed Avg. Running

Speed Total Delay

11:17 AM 594.3 17.2 27.9 228.7

11:48 AM 594.7 17.1 28.8 241.1

12:14 PM 841.9 12.1 22.1 381.4

Basic Statistics:


Travel Time (s)

Average Journey Speed (kmph)

Average Running Speed (kmph)

Total Delay (s)



Standard Deviation




108.09



Travel Time (s) Average Journey Speed(kmph)

Average Running Speed(kmph)

Total Delay(s)



Standard Deviation




84.78


Graphically the data have been represented on the next page.

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0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

10:48 AM 11:02 AM 11:16 AM 11:31 AM 11:45 AM 12:00 PM 12:14 PM 12:28 PM 12:43 PM

0.0

100.0

200.0

300.0

400.0

500.0

600.0

700.0

800.0

10:48 AM 11:02 AM 11:16 AM 11:31 AM 11:45 AM 12:00 PM 12:14 PM 12:28 PM 12:43 PM

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

11:09 AM 11:24 AM 11:38 AM 11:52 AM 12:07 PM 12:21 PM

Spee

d (

kmp

h)

Del

ay (

s)

Average

Running Speed

Average Journey

Speed

Travel Time

Total Delay

Average

Running Speed

Average Journey

Speed

Spee

d (

kmp

h)

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The inferences that can be drawn from the above results are as below:

It can be concluded by back-extrapolating the curves that the morning off-

peak hour of traffic was effectual since sometime before the first observation

was taken i.e. 11:05 am. However, it can be conclusively said that the end of

this off-peak period is around 12:00 pm.

The average travel times during the off-peak hour in both the directions are

comparable. For D1 direction the value is 9 mins while that in D2 direction is

9 mins 55 secs (median values). This indicates that during off-peak hours the

flow rate is almost the same in both the directions, if we assume that the

capacity of the roadway in both the directions is same.

The tables show that the standard deviations in travel times for both the

directions are large. However, such a result is obtained if we consider all the

data points which include the observations taken after 11:50 pm when the

intermediate peak-hour had begun resulting in sudden spiking of the travel

times. Excluding such observations, we find standard deviations of 63 secs

and only 0.28 secs for D1 and D2 directions respectively.

The above point emphasizes that while there is a smooth variation in the

travel times in the D1 direction, there are abrupt variations in the D2 direction

as there is a transition from off-peak period to intermediate peak period.

In both the directions the average journey speed and the average running

speed follow the similar distributions i.e. the curves almost perfectly follow

each other. Thus, the phenomenon of accelerating in the mid-block sections

as found during the peak hour in D2 direction is non-existent in this case.

The average running speed (median value 26.55 kmph) in D1 direction and

that in the D2 direction (median value 27.89 kmph) are comparable but 55%

and 53% lower respectively, when compared to the safe speed of 60 kmph.

The total delays from CRRI towards Ashram are 33% higher than that in the

opposite direction, when the median values are compared.

0.0

100.0

200.0

300.0

400.0

500.0

600.0

700.0

800.0

900.0

11:02 AM 11:16 AM 11:31 AM 11:45 AM 12:00 PM 12:14 PM 12:28 PM

Del

ay (

s)

Travel Time

Total Delay

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As noted before, due to the abrupt increase of travel time at the start of

intermediate peak hour the variations in average running speed in D2

direction are higher when compared to the D1 direction. However, the

variations in the average journey speeds in both directions are comparable.

The bottleneck portions identified in both the directions with respective causes

of delay are given in the table below:



Ashram - Mata Ka Mandir 290.1 Red Signal, RT traffic and Queuing of vehicles at the signal which takes a long

time to clear.

Mata Ka Mandir - NFC 38.3 Queuing of vehicles at the signal.

NFC – Kalka Mod 7.16 Due to the traffic merging from the off-ramp of the

Kalkaji flyover and pedestrians crossing the

road.

Kalka Mod - CRRI 4.5 Red signal



CRRI – Kalka Mod 0 -

Kalka Mod - NFC 139.1 Traffic merging from the off-ramp of the Kalkaji

flyover and traffic turning right towards NFC district

centre. Also the queuing of straight through vehicles

at the signal and the pedestrians crossing the road near Kalkaji flyover

and also at the NFC intersection.

NFC – Mata Ka Mandir 90.9 Red Signal

Mata Ka Mandir - Ashram 212.9 Red Signal and queuing.

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LIMITATIONS

The most severe limitation of this study us that the numbers of observations are

limited which reduces the credibility of the conclusions drawn from the results

obtained.

The results of this study could not be substantiated by a Traffic Volume Count which

justified their claims about the starting and ending times of the peak and off-peak

periods.

Apart from that, the observers felt great difficulty in discerning the factors causing

delays during the runs and hence the various factors had to be clubbed in order to

define the causes of delay at a particular point. Thus, delays being caused by

individual factors (e.g. how much is the delay caused by the queue of vehicles ahead

of the survey vehicle taking time to start moving even after the signal has turned

green much before) could not be represented which could provide better information

regarding the traffic bottlenecks.

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REFERENCES

Santosh A. Jalihal, K. Ravindar, T.S. Reddy (2005)1. Traffic Characteristics

of India. Central Road Research Institute.

www.delhiplanning.nic.in. “Economic Survey of Delhi – Chapter 12.”

S.K. Khanna and C.E.G Justo. Highway Engineering (book).

www.maps.google.com

http://www.delhiplanning.nic.in/

http://www.maps.google.com/

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