Top of Form 1.  Stream quality is based on the levels of many variables, including the following. Which of these variables is quantitative? The amount of dissolved oxygen The number of distinct species present The amount of phosphorus All of the above 2.  Which of the following is a discrete variable? Weight of a fish Length of a fish None of the above Number of toxins present in a fish 3.  During winter, red foxes hunt small rodents by jumping into thick snow cover. Researchers report that a hunting trip lasts on average 19 minutes and involves on average 7 jumps. They also report that, surprisingly, 79% of all successful jumps are made in the northeast direction. Three variables are mentioned in this report. The first variable mentioned is ordinal. quantitative and discrete. quantitative and continuous. categorical. 4.  A sample of 55 streams in severe distress was obtained during 2007. The following is a bar graph of the number of streams that are from the Northeast, Northwest, Southeast, or Southwest. In the bar graph, the bar for the Northeast has been omitted. The number of streams from the Northeast is 35. 25. 15. 45. 5.  Here is a stemplot (with split stems) of body temperatures (in degrees Fahrenheit) for 65 healthy adult women. The first quartile for this data set is 97.6. 97.5. 98.0. 97.9. 6.  Researchers measured the length of the central retrix (R1), a flight-involved tail feather, in 21 female long-tailed finches. Here is a boxplot of the length, in millimeters (mm). Based on this boxplot, which of the following statements is TRUE? The distribution of R1 lengths is bimodal. The distribution of R1 lengths is mildly right-skewed with a high outlier. 75% of the birds in this study had an R1 length above 70 mm. All of the above 7.  Geckos are lizards with specialized toe pads that enable them to easily climb all sorts of surfaces. A research team examined the adhesive properties of 7 Tokay geckos. Below are their toe-pad areas (in square centimeters, cm2). 5.6 4.9 6.0 5.1 5.5 5.1 7.5 To be an outlier, an observation must fall outside the range 4.9 to 7.5. 4.2 to 6.9. 3.75 to 7.35. 5.1 to 6.0. 8.  The median age of five people on a committee is 30 years. One of the members, whose age is 50 years, resigns. The median age of the remaining four people in the committee is not able to be determined from the information given. 25 years. 30 years. 40 years. 9.  By inspection, determine which of the following sets of numbers has the smallest standard deviation. 7, 8, 9, 10 0, 0, 10, 10 0, 1, 2, 3 5, 5, 5, 5 10.  The volume of oxygen consumed (in liters per minute) while a person is at rest and while he or she is exercising (running on a treadmill) was measured for each of 50 subjects. The goal is to determine if the volume of oxygen consumed during aerobic exercise can be estimated from the amount consumed at rest. The results are plotted below. The scatterplot sugges ...

1. Top of Form
1.
Stream quality is based on the levels of many variables,
including the following. Which of these variables is
quantitative?
The amount of dissolved oxygen
The number of distinct species present
The amount of phosphorus
All of the above
2.
Which of the following is a discrete variable?
Weight of a fish
Length of a fish
None of the above
Number of toxins present in a fish
3.
During winter, red foxes hunt small rodents by jumping into
thick snow cover. Researchers report that a hunting trip lasts on
average 19 minutes and involves on average 7 jumps. They also

2. report that, surprisingly, 79% of all successful jumps are made
in the northeast direction. Three variables are mentioned in this
report. The first variable mentioned is
ordinal.
quantitative and discrete.
quantitative and continuous.
categorical.
4.
A sample of 55 streams in severe distress was obtained during
2007. The following is a bar graph of the number of streams
that are from the Northeast, Northwest, Southeast, or
Southwest. In the bar graph, the bar for the Northeast has been
omitted.
The number of streams from the Northeast is
35.
25.
15.
45.
5.

3. Here is a stemplot (with split stems) of body temperatures (in
degrees Fahrenheit) for 65 healthy adult women.
The first quartile for this data set is
97.6.
97.5.
98.0.
97.9.
6.
Researchers measured the length of the central retrix (R1), a
flight-involved tail feather, in 21 female long-tailed finches.
Here is a boxplot of the length, in millimeters (mm).
Based on this boxplot, which of the following statements is
TRUE?
The distribution of R1 lengths is bimodal.
The distribution of R1 lengths is mildly right-skewed with a
high outlier.
75% of the birds in this study had an R1 length above 70 mm.
All of the above

4. 7.
Geckos are lizards with specialized toe pads that enable them to
easily climb all sorts of surfaces. A research team examined the
adhesive properties of 7 Tokay geckos. Below are their toe-pad
areas (in square centimeters, cm2).
5.6
4.9
6.0
5.1
5.5
5.1
7.5
To be an outlier, an observation must fall outside the range
4.9 to 7.5.
4.2 to 6.9.
3.75 to 7.35.
5.1 to 6.0.
8.
The median age of five people on a committee is 30 years. One
of the members, whose age is 50 years, resigns. The median age
of the remaining four people in the committee is
not able to be determined from the information given.
25 years.
30 years.

5. 40 years.
9.
By inspection, determine which of the following sets of
numbers has the smallest standard deviation.
7, 8, 9, 10
0, 0, 10, 10
0, 1, 2, 3
5, 5, 5, 5
10.
The volume of oxygen consumed (in liters per minute) while a
person is at rest and while he or she is exercising (running on a
treadmill) was measured for each of 50 subjects. The goal is to
determine if the volume of oxygen consumed during aerobic
exercise can be estimated from the amount consumed at rest.
The results are plotted below.
The scatterplot suggests that
there is a positive association between the volume of oxygen
consumed at rest and while running.
there is an outlier in the plot.
both 1 and 2 are true.

6. neither 1 nor 2 is true.
11.
Bird species from temperate regions must cope with relatively
short breeding seasons. A study examined the relationship
between blood testosterone level (ng/ml) and the duration of the
egg-laying period (months) in temperate bird species. The
scatterplot below displays this relationship, after taking the
logarithm of each variable.
A plausible value for the correlation between the logarithm of
egg-laying duration and the logarithm of testosterone level is
–0.9.
–0.4.
+0.2.
+0.8.
12.
When water flows across farm land, some of the soil is washed
away, resulting in erosion. An experiment was conducted to
investigate the effect of the rate of water flow (in liters per
second) on the amount of soil washed away (in kilograms). The
data are given in the following table.
Flow rate
0.31
0.85
1.26
2.47

7. 3.75
Eroded soil
0.82
1.95
2.18
3.01
6.07
The association between flow rate and amount of eroded soil is
neither positive nor negative.
positive.
impossible to determine since both variables are categorical.
negative.
13.
Which of the following is TRUE of the correlation coefficient
r?
If r is the correlation between X and Y, then –r is the
correlation between Y and X.
All of the above
–1 r 1.
It is a resistant measure of association.
14.

8. Researchers want to know if reading skills can explain IQ test
scores in children with dyslexia. The following scatterplot
examines the relationship between reading skill score and IQ
test score for 22 dyslexic children. The least-squares regression
line is displayed on the plot, along with the value of r2.
The intercept of the least-squares regression line
cannot be determined from the graph, even approximately.
is greater than 120.
is less than 50.
is about 80, approximately.
15.
Researchers want to know if reading skills can explain IQ test
scores in children with dyslexia. The following scatterplot
examines the relationship between reading skill score and IQ
test score for 22 dyslexic children. The least-squares regression
line is displayed on the plot, along with the value of r2.
What percent of the variation in IQ test scores is explained by
this regression model?
5%
48%
23%

9. 52%
16.
Before surgical removal of a diseased parathyroid gland, two
tests are often performed: the standard intact test and the turbo
test. Both tests measure parathyroid hormone (PTH, in ng/l), but
the turbo test is very expensive. Researchers obtained data from
both tests in a sample of 48 patients to predict turbo test results
(y) from standard intact test results (x). The data ranged from
roughly 0 to 500 ng/l, and a scatterplot showed a clear linear
relationship. The published findings are summarized exactly as
follows:
y = 1.08x – 4.36 (r = 0.97; n = 48)
For a PTH level of x = 1000 ng/l with the standard intact test,
the predicted PTH level with the turbo test
is 1075.64 ng/l.
is 1036.4 ng/l.
cannot be predicted accurately because it would be
extrapolating.
is 970 ng/l.
17.
Babies typically learn to crawl approximately six months after
birth. However, it may take longer for babies to learn to crawl
in the winter, when they are often bundled in clothes that
restrict their movement. Thus, there may be an association
between a baby's crawling age and the average temperature
during the month they first try to crawl. Below are the average

10. ages (in weeks) at which babies began to crawl for a sample of
babies born in each of the 12 months of the year. In addition,
the average temperature (in °F) for the month that is six months
after the birth month is also listed.
Birth month
Average crawling age
Average temperature
January
29.84
66
February
30.52
73
March
29.70
72
April
31.84
63
May
28.58
52
June
31.44
39
July
33.64
33
August
32.82
30
September
33.83
33
October
33.35

11. 37
November
33.38
48
December
32.32
57
We want to investigate if the average age at which infants begin
to crawl (y) can be predicted from the average outdoor
temperature (x) six months after birth, when they are likely to
begin crawling. We decide to fit a least-squares regression line
to the data with x as the explanatory variable and y as the
response variable. We compute the following quantities.
r = correlation between x and y = –0.7
= mean of the values of x = 50.25
= mean of the values of y = 31.77
sx = standard deviation of the values of x = 15.85
sy = standard deviation of the values of y = 1.76
Which of the following is closest to the slope of the least-
squares line?
0.08
–0.08
6.30
–6.30
18.
Babies typically learn to crawl approximately six months after

12. birth. However, it may take longer for babies to learn to crawl
in the winter, when they are often bundled in clothes that
restrict their movement. Thus, there may be an association
between a baby's crawling age and the average temperature
during the month they first try to crawl. Below are the average
ages (in weeks) at which babies began to crawl for a sample of
babies born in each of the 12 months of the year. In addition,
the average temperature (in °F) for the month that is six months
after the birth month is also listed.
Birth month
Average crawling age
Average temperature
January
29.84
66
February
30.52
73
March
29.70
72
April
31.84
63
May
28.58
52
June
31.44
39
July
33.64
33
August
32.82
30

13. September
33.83
33
October
33.35
37
November
33.38
48
December
32.32
57
We want to investigate if the average age at which infants begin
to crawl (y) can be predicted from the average outdoor
temperature (x) six months after birth, when they are likely to
begin crawling. We decide to fit a least-squares regression line
to the data with x as the explanatory variable and y as the
response variable. We compute the following quantities.
r = correlation between x and y = –0.7
= mean of the values of x = 50.25
= mean of the values of y = 31.77
sx = standard deviation of the values of x = 15.85
sy = standard deviation of the values of y = 1.76
The fraction of the variation in the values of a response y that is
explained by the least-squares regression of y on x is the
intercept of the least-squares regression line.
correlation coefficient.
square of the correlation coefficient.

14. slope of the least-squares regression line.
19.
The city council in a suburb of Raleigh is interested in the level
of public support for a tax increase to support restoration of
nearby parks and waterways. A marketing research firm is
selected that then selects a simple random sample of 50 adult
residents and contacts each to determine whether the resident
would be opposed to the tax increase. Of these, 15 indicated
that they would be opposed.
The population of interest is
all adult residents in the suburb.
the residents in the suburb that are opposed to the tax increase.
the 50 residents contacted.
all households in the suburb.
20.
The National Health and Nutrition Examination Survey
(NHANES) assesses the health and nutritional status of
Americans. A recent NHANES asked a random sample of
17,567 American adults to fill a detailed questionnaire about
what they ate the previous day and give their body mass index
(BMI). The researchers then compared individuals who ate
avocado with those who didn't, and found that BMI was lower,
on average, among those who ate avocado. This is an example
of

15. a survey using a probability sample.
a retrospective case-control study.
just anecdotal evidence.
a prospective cohort.
21.
You need to select three subjects from a list of nine subjects.
The subjects' names are provided below.
1. Berliner
4. Wolfe
7. Verducci
2. Blumenthal
5. Stasny
8. Lin
3. MacEachern
6. Santner
9. Critchlow
Use the numerical labels attached to the names and the
following list of random digits to select three individuals. Read
the list of random digits from left to right, starting at the
beginning of the list.
44982 20751 27498 12009 45287 71753 98236 66419 84533
11793 20495 05907 11384
Which of the following statements is TRUE?
If we used another list of random digits to select the sample, the
result obtained with the list actually used would be just as
likely to be selected as any other set of three names.

16. If we used another list of random digits to select the sample, we
would get a completely different sample than that obtained with
the list actually used.
If we used another list of random digits to select the sample, we
would get at most one name in common with a name obtained
with the list actually used.
If we used another list of random digits to select the sample, we
would get the same result as obtained with the list actually
used.
22.
Sixty-four pregnant women ranked the severity of their
heartburn during pregnancy. Researchers rated newborn hair
volume using photographs of the newborn's head. They found an
association between heartburn severity during pregnancy and
the amount of hair on newborns. What can we reasonably
conclude from this study?
Pregnancy is confounded with heartburns in deciding the cause
of newborn hair amount.
Newborn hair causes heartburns in pregnant women.
Eating food causing heartburns during pregnancy leads to
newborns that are hairier.
A lurking variable likely influences both the severity of
heartburns in pregnant women and the amount of hair on
newborns.
23.

17. A March 2010 SurveyUSA telephone poll asked about issues
facing central Ohio to a random sample of 500 households in
the Columbus, Ohio, area. One question was: “Where 10 means
most important, and 1 means least important, how important is
protecting the environment?” The average response was 6.0.
What population is the poll targeting?
The poll targets the 500 households in the Columbus area who
responded.
The poll targets all households with a strong opinion on the
environment in the Columbus area.
The poll targets registered voters in the Columbus area.
The poll targets all households in the Columbus area.
24.
A researcher is interested in investigating the relationship
between sugar consumption and weight gain for high school
students. Fifteen volunteers were randomly assigned to one of
two groups. The first group contained six volunteers who were
put on a low-sugar diet. The second group consisting of the
remaining nine volunteers was put on a diet with sugar
constituting approximately 15% of their diet. After eight weeks,
the change in weight was recorded for each of the volunteers.
The response is the
eight-week time period.
assignment to groups.

18. percent of sugar in the diet.
change in weight.
25.
A researcher was studying how the weights of horseshoe crabs
along the east coast varied between northern and southern
habitats. In spring 2006, during breeding season, the researcher
randomly selected 50 horseshoe crabs in southern habitats. In
fall 2006, before breeding season begins, the researcher
randomly selected 50 horseshoe crabs from northern habitats. It
was found that crabs in southern habitats weighed more and so
the researcher claimed that location had an effect on weight of
horseshoe crabs. The results cannot be trusted because the
investigator should have used more than two locations.
investigator was biased. She knew beforehand what the study
would show.
time of year during which the samples were taken is a
confounding variable.
study was not double-blind.
26.
Researchers wish to determine if a new experimental medication
will reduce the symptoms of allergy sufferers without the side
effect of drowsiness. To investigate this question, the
researchers give the new medication to 50 adult volunteers who
suffer from allergies. Forty-four of these volunteers report a
significant reduction in their allergy symptoms without any

19. drowsiness.
This study could be improved by
including people who do not suffer from allergies in the study
in order to represent a more diverse population.
repeating the study using only the volunteers who reported a
significant reduction in their allergy symptoms without any
drowsiness and giving them a higher dosage this time.
using a control group.
All of the above
27.
Will a fluoride mouthwash used after brushing reduce cavities?
Twenty sets of twins were used to investigate this question. One
member of each set of twins used the mouthwash after each
brushing, the other did not. After six months, the difference in
the number of cavities of those using the mouthwash was
compared with the number of those who did not use the
mouthwash. This experiment uses
double replication.
a matched pairs design.
double-blinding.
random placeboes.

20. 28.
A study examined the effect of garlic on blood cholesterol
levels. A total of 192 subjects with starting LDL (“bad
cholesterol”) levels between 130 and 190 mg/dl were randomly
assigned to one of four treatments for six months: raw garlic
eaten daily, a powdered garlic supplement taken daily (Garlicin
brand), an aged-garlic extract taken daily (Kyolic brand), or a
placebo pill taken daily. The study found no significant or
clinical differences in blood cholesterol levels between the four
groups at the end of the study.
This study uses the principles of
randomization.
blinding.
blocking.
All of the above
29.
A population has an equal proportion of males and females.
That is, when randomly selecting one individual, the probability
that the individual is male (M) is 1/2 and the probability that
the individual is female (F) is 1/2.
In the first 50 randomly selected individuals, 20 were male. In
the next 50 randomly selected individuals, which of the
following must happen?
More than half of the individuals will be males to balance out
the low number of males in the first 50 individuals. However,

21. the order in which these males will be selected is unpredictable.
More than 20 of the individuals will be males because the
proportion of males after 100 individuals must be closer to 1/2
than the proportion after 50 individuals.
The number of males will be very close to 30 in the next 50
individuals because the proportion must be close to 1/2 after
100 individuals.
None of the above
30.
The Centers for Disease Control and Prevention receives
information about the causes for HIV/AIDS infection in the
United States. Here are the causes of infection and their
respective probability among American women ages 20 to 24
years old.
Cause
Probability
Injection drug use
?
Heterosexual sex
0.664
Perinatal infection
0.125
Other causes
0.095
The probability that an American woman age 20 to 24
contracted HIV/AIDS either via heterosexual sex or via
perinatal infection is
0.789.

22. 0.211.
0.500.
0.083.
31.
Based on a recent Gallup survey, we define the following
probability model for the number X of daily cups of coffee
consumed by Americans.
X
0
1
2
3
4 or more
Probability
0.36
0.26
0.19
0.09
?
The probability that an American does not consume 2 cups of
coffee daily is _______ .
32.
A variable whose value is a numerical outcome of a random
phenomenon is called

23. a random variable.
biased.
a random sample.
a parameter.
33.
The frequency of color blindness (dyschromatopsia) in the
Caucasian American male population is estimated to be about
8%. Let's call X the number of color-blind individuals in a
random sample of 8 Caucasian American males. The table below
gives the probability distribution for X.
X
0
1
2
3
4
5
6
7
8
P(X)
0.513
0.357
0.109
0.019
0.002
0.000
0.000
0.000
0.000

24. What is the probability of getting 1 or 2 color-blind individuals
in the sample?
0.248
0.870
0.466
0.039
34.
Using the standard Normal distribution tables, the area under
the standard Normal curve corresponding to Z > –2.62 is
0.0047.
0.9956.
0.0044.
0.9953.
35.
The pH measurements of water specimens from various
locations along a given river basin are Normally distributed
with mean 8 and standard deviation 0.3.
What is, approximately, the probability that the pH
measurement of a randomly selected water specimen is greater
than 8.2?

25. 0.2525
0.7475
0.7525
0.2475
36.
A researcher is interested in the lengths of Salvelinus fontinalis
(brook trout), which are known to be approximately Normally
distributed with mean 80 centimeters and standard deviation 5
centimeters. To help preserve brook trout populations, some
regulatory standards need to be set limiting the size of fish that
can be caught. The probability of catching a brook trout less
than 72 centimeters in length is
0.3745.
0.9452
0.0548.
0.6255.
37.
A researcher is interested in the lengths of Salvelinus fontinalis
(brook trout), which are known to be approximately Normally
distributed with mean 80 centimeters and standard deviation 5
centimeters. To help preserve brook trout populations, some
regulatory standards need to be set limiting the size of fish that
can be caught. To ensure that the shortest 8% of the brook trout

26. get thrown back, the lower cut-off should be set at
75.00 centimeters.
87.03 centimeters.
72.95 centimeters.
80.00 centimeters.
38.
The distribution of total body protein in adult men with liver
cirrhosis is approximately Normal with mean 9.8 kg and
standard deviation 0.1 kg.
Twenty-five percent of adult men with cirrhosis have a total
body protein of at least
9.87 kg.
9.73 kg.
9.70 kg.
9.60 kg.
39.
The amount of cholesterol in a person's body produced by their
liver and other cells is proposed to be Normally distributed with
mean 75% and standard deviation 0.5%.
The probability that a person produces more than 76.7% of the

27. cholesterol in their body is
0.9997.
1.
0.0006.
0.0003.
40.
A national survey by Gallup interviewed 1014 adults and found
that they had consumed on average 4.2 alcoholic beverages in
the past seven days.
Considering a sample of 1014 adults a large sample, which of
the following is TRUE?
By the central limit theorem, the 1014 weekly number of drinks
obtained in the sample are approximately Normally distributed.
By the law of large numbers, the results of this study are 1014
times less variable than if only one American adult had been
asked.
By the law of large numbers, the average weekly number of
drinks from repeated samples of size 1014 is approximately
Normally distributed.
By the central limit theorem, the average weekly number of
drinks from repeated samples of size 1014 is approximately
Normally distributed.

28. 41.
The fact that the sample mean doesn't tend to over- or under-
estimate the population mean makes the sample mean
consistent.
a statistic.
unbiased.
efficient.
42.
You plan to randomly select 10 students from your campus and
ask them how many minutes they exercised in the past seven
days.
The distribution of values taken by the average exercising time
in all possible samples of size 10 is the
variance of the exercising time values.
probability distribution of exercising times.
population parameter.
sampling distribution of average exercising times.
43.
The variability of a statistic is described by the

29. spread of its sampling distribution.
vagueness in the wording of the question used to collect the
sample data.
amount of bias present.
stability of the population it describes.
44.
The pH measurements of water specimens from various
locations along a given river basin are Normally distributed
with mean 8 and standard deviation 0.3. You take water
specimens from 4 randomly selected locations on this river
basin.
Use the 68–95–99.7 rule to answer this question. What is the
range of average pH measurements that make up roughly the
middle 95% of the sampling distribution for random samples of
4 specimens?
7.7 to 8.3
7.4 to 8.6
7.85 to 8.15
7.925 to 8.075
45.
The distribution of total body protein in adult men with liver
cirrhosis is approximately Normal with mean 9.8 kg and

30. standard deviation 0.1 kg.
If you take a random sample of 25 adult men with liver
cirrhosis, what is the probability that their average total body
protein is between 9.75 and 9.85 kg?
0.3829
0.0796
0.0062
0.9876
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EN251 -3428/2013; WABURI FRANCIS GATUBU
TRAFFIC ENGENEERING PROJECT
JOMO KENYATTA UNIVERSITY OF AGRICULTURE AND
TECHNOLOGY
NAME: WABURI FRANCIS GATUBU
REG NO: EN251-3428/2013
COURSE: BSc CIVIL ENGINEERING
UNIT: TRAFFIC ENGINEERING 1
UNIT CODE: ECE 2404
LECTURER: PROF GARIY
SUBMITED ON: DEC 2015
Traffic Management during Construction Work of Ngong
RoadIntroduction
Managing traffic is essential to providing a safe construction
workplace. Traffic can include cars, utilities, delivery trucks,
forklifts, excavators and pedestrians such as workers and
visitors.

32. Vehicles including powered mobile plant moving in and around
workplaces, reversing, loading and unloading are activities
frequently linked with workplace injuries and fatalities.
The safest way to protect pedestrians is to eliminate the hazard,
which means removing the use of all vehicles including
powered mobile plant or removing all pedestrians from traffic
areas. This could be achieved by designing the layout of the
workplace to eliminate the interaction of pedestrians and
vehicles.
Where this is not reasonably practicable, the risks must be
minimised so far as is reasonably practicable. This can be
achieved by careful planning and by controlling vehicle
operations and pedestrian movements at the workplace. This
includes loading/unloading activities.
The key issues to consider for managing traffic at a construction
workplace include:
· keeping pedestrians and vehicles apart, including on site and
when vehicles enter and exit the workplace
· minimising vehicle movements
· the risks of vehicles reversing
· visibility of vehicles and pedestrians
· traffic signs
· Developing a traffic management plan.
Information, instruction and training
All workers need to know and understand the traffic rules, site
safety policies and procedures for the workplace. Instructions
should be provided to visitors before their visit, if possible.
Other persons at the workplace, so far as they’re able, must
comply with any reasonable instruction that is given by the
KENHA. They must also take reasonable care for their own
health and safety and that they do not adversely affect the
health and safety of others.Keeping pedestrians and vehicles
apart
The following actions will help keep pedestrians and vehicles

33. apart both on site and when vehicles enter or exit the
workplace:
· provide separate traffic routes for pedestrians and vehicles
· secure the areas where vehicles and powered mobile plant are
being used, for example pedestrian barriers or traffic control
barricades
· provide separate clearly marked pedestrian walkways that take
a direct route where possible
· where walkways cross roadways, provide a clearly signed and
lit crossing point where drivers and pedestrians can see each
other clearlyMinimising vehicle movements
Good planning can help to minimise vehicle movement around a
workplace.
To limit the number of vehicles at a workplace:
· provide vehicle parking for workers and visitors away from
the work area
· control entry to the work area
· plan storage areas so that delivery vehicles do not have to
cross the site.
Where multiple items of powered mobile plant are being
operated around the workplace, a person with the necessary
training or qualifications should direct the plant:
· ensure workers and other people are familiar with reversing
areas and reversing areas are clearly marked
· Ensure operational plant movements are alerted to workers
including swing radius, articulation points and overhead load
movement.Visibility of vehicles and pedestrians
The WHS laws require that if there is a possibility of powered
mobile plant colliding with pedestrians or other powered mobile
plant, with management or control of the plant must ensure that
it has a warning device that will warn persons who may be at
risk from the movement of the plant.
The following measures should be considered:
. Signs
Prominently display clear warning signs in relevant, well lit
areas to remind persons of the traffic management hazards and

34. requirements. Excavations should be clearly signed.Traffic
routes should be clearly sign posted to indicate restricted
parking, visitor parking, Diversion, headroom, speed limits,
vehicle movement, key site areas and other route hazards.
Standard road signs should be used where possible and speed
limits should be implemented and enforced. Traffic management
plans
A traffic management plan can help manage risks and
communicate information regarding control measures. It may
include details of:
· the designated travel paths for vehicles including entry and
exit points, haul routes for debris or plant/materials, or traffic
crossing another stream of traffic
· pedestrian and traffic routing
· traffic controls for each expected interaction, including
illustrations of the layout of barriers, walkways, signs and
general arrangements to warn and guide traffic around, past, or
through the workplace or temporary hazard
· requirements for special vehicles (e.g. over-dimensional)
· requirements for loading from side of road onto the site
· travel paths on routes remote from the workplace such as
places to turn around, dump material, access ramps and side
roads
· designated delivery and loading/unloading areas
· the expected frequency of interaction of vehicles and
pedestrians
· roles and responsibilities of persons in the workplace for
traffic management
· Instructions or procedures associated with the control of
traffic, including in an emergency.
The traffic management plan should be regularly monitored and
reviewed to ensure it is effective and to take into account any
changes at the workplace.
All workers should be familiar with the traffic management plan
and receive sufficient information, instruction, training, and
supervision.

35. CONSTRUCTION TRAFFIC MANAGEMENT PLAN
The Traffic Management Plan for the reconstruction phases of
the approved Ngong road development is set down through the
following sections:
1. site location and road network;
2. approved development;
3. overall principles for traffic management;
4. hours of work;
5. truck routes;
6. traffic and parking effects;
7. pedestrians;
8. consultation;
9. pedestrian and traffic management plan;
Site Location and Road Network
Ngong road is located between Kenyatta hospital and Adams
arcade. It provides a four lane carriageway with two traffic
lanes in each direction. Major intersections are signalized with
additional lanes for turning traffic. Clearways operate in peak
periods. Bus stops are
Provided on both sides of the road. There is a short term
parking area on Ngong road
For set down and pick up adjacent to the site.
The table below describes various routes that are commonly
used to Ngong through Ngong need
Bus Routes
Route
Destination
Route Description
4W
Riruta Satellite
Kenyatta Ave, Community, Kenyatta Hospital, Ngong Rd,
Adams Arcade, Woodley, Jamhuri, Dagoretti Corner, Riruta
Satellite

36. 5
Jamhuri Estate
Kenyatta Ave, Serena, Community, Kenyatta Hospital, Ngong
Rd, Adams Arcade, Woodley, Jamhuri Estate
7C
Kenyatta National Hospital
Kenyatta Ave, Serena, Community, Upper Hill, Kenyatta
National Hospital
8
Kibera (via Ngong Rd)
Kenyatta Avenue, Serena, Community, Kenyatta Hospital,
Ngong Rd, Mugo Kibiru Rd, Kibera Drive, Kibera Ayany Estate
24
Karen
Haile Selassie Avenue, Ngong Rd, Adams Arcade, Woodley,
Jamhuri, Dagoretti Corner, Karen, Hardy
32
Kibera (via Argwings Kodhek Rd)
Kenyatta Avenue, Serena, Panafric, Valley Road, Argwings
Kodhek Road, Hurligham, Kilimani, Yaya Centre, Ring Road
Kilimani, Adams Arcade, Kibera Drive, Kibera Ayany Estate
40
Ngumo Estate
Kenyatta Avenue, Serena, Community, Ngong Road, Kenyatta
Hospital, Mbagathi Road, Kenyatta Market, Ngummo Estate
46
Kawangware
Kenyatta Avenue, Serena, Panafric, Valley Road, Argwings
Kodhek Road, Hurlingham, Kilimani, Yaya Centre, Korosho
Road, Gitanga Road, Kawangware
Overall Principles for Traffic Management
The beneficiary of this Construction Traffic Management Plan
will comply with
Any other conditions imposed by the City’s Construction

37. Regulations Unit.
The overall principles for traffic management during
demolition, excavation and
Construction phases of the development are:
1. provide a convenient and appropriate environment for
pedestrians;
2. minimise effects on pedestrian movements and amenity;
3. manage and control vehicular movements to and from the
site;
4. maintain traffic capacity at intersections and mid-block in
the vicinity of the site;
5. maintain existing on-street parking in the vicinity of the site
where practical;
6. maintain access to other properties adjacent to the site;
7. restrict vehicle activity to designated truck routes through
the area;
8. maintain safety for workers;
9. provide appropriate access to the site for demolition,
excavation and
10. construction traffic;
11. Manage and control vehicle activity in the vicinity of the
site.
Hours of Work
In accordance with the set traffic management rules, work
associated with demolition, excavation and construction for the
development will be carried out between the following
Hours:
1. Monday to Friday: 7:30 am to 5:30 pm;
2. Saturday: 7:30 am to 3:30 pm; and
3. Sunday/Public Holidays: no work.
Any works outside these times would be subject to a separate
application to the
City of Nairobi. The control of hours of operation avoids truck
movements during
The early hours of the morning, before 7:30 am and in the
evening, after 5:30 pm.

38. Truck Routes and Access
It is proposed that trucks travel to and from the site along the
following designated construction routes. This is during the
demolition, excavation and Construction stages:
.Approach Routes
1. Kenyatta hospital
2. Adams arcade
3. Ndagoretti corner
4. Kimbera
During construction of the development, trucks bringing
material to the site will be accommodated on site .The
designated truck routes to and from the site are proposed to
restrict truck traffic, as far as possible to the main road network
through the area. The approach and departure routes of
construction vehicles to and from the site are considered
appropriate. All demolition, excavation and construction phase
traffic will enter and leave the site from and to Ngong Road
except for vehicles required for works along other Street
frontage where access cannot be reasonably obtained from
Ngong Road. In this instance access may be obtained from the
other route past Ngong road.
Ngong Road including piling rigs, excavators and the like. The
beneficiary of the construction traffic management plan will
comply with any other conditions Imposed by the City of
Nairobi Construction Regulation Unit. Excavation or demolition
spoil removal is not an exception.
During demolition and excavation, trucks transporting material
from the site will be accommodated on site. The approach and
departure routes of construction vehicles to and from the site
are considered appropriate.
Traffic and Parking Effects
During the demolition and excavation period, there will be a
total of some 15 to
20 trucks per day taking demolition and excavated material

39. from the site. During construction of the development from
Ngong Road, peak activity would occur during Bitumen
placement/pour. During larger pours, some 15 to 20 tarmac
trucks per day would be required. For smaller pours, some 10-
20 concrete trucks would be required. At other times, deliveries
of construction materials to the site would be lower at some 10
to 20 trucks per day.
Consultation
A construction committee will be established. Meetings of the
committee will be held monthly or at other appropriate intervals
to discuss construction matters. Local residents and other
relevant parties will continue to be informed of these meetings
and other construction issues by email notification and letter
box drops. For matters relating to the construction process,
local residents will be able to contact the appointed contractor
or project manager by telephone or email. A dedicated
telephone number has been established by the project managers
Which will be transferred to the contractor once it has been
appointed.
Pedestrian and Traffic Management
Signage, fencing, overhead protection, safety barriers and line
marking details, as required, will be provided in accordance
with British Standards and the Roads and Traffic Authority's
Manual for Traffic Control at Work Sites. A copy of the
Construction Traffic Management Plan will be kept on-site at
all times. Signage details, the control of pedestrians in the
vicinity of the site, and the control of trucks to and from the site
will be the responsibility of the site Contractor. The pedestrian
and traffic management plan for the demolition and excavation
Includes the following:
1. demolition and excavation activity to be provided for on-
site;

40. 2. demolition and excavation vehicle access to the site will be
provided from
3. the movement of trucks on and off the site to be managed and
controlled by
Appropriately qualified site personnel in accordance with a Safe
Work Method
Statement and Traffic Control Plans; truck movements to and
from the site to be restricted to designated truck routes shown
on the attached.
4. The management of the site works will be the responsibility
of the site i.e. watering to ensure no dust during the
reconstruction.
5. pedestrian arrangements, construction activity and erection
of safety fencing will be provided in accordance with Workover
requirements; and construction signage to be provided in Ngong
Road and other Street in accordance with the Roads and Traffic
Authority's
Manual for Traffic Control at Work Sites.
The pedestrian and traffic management plan for the demolition,
excavation and
Construction phases of the development is considered
appropriate to provide for
Traffic and pedestrian activity. It may be updated when more is
known about the
Construction Phase.
The works zone will be required during the construction
Period, and will extend along the site frontage (approximately
50 meters). Works zone
Time restrictions will be in accordance with the approved hours
of operation. The City of
Nairobi traffic committee has raised no objection to a possible
future works zone directly
In Ngong Road.

41. CONCLUSION
The road shall thus be constructed in sections and the traffic
will be diverted at different sections of the road. The works will
start by first expanding the road way on its shoulders and later
joining the left-hand side and the right hand side after all works
have been completed this is by working on the road reserves so
as to avoid interrupting the existing traffic. Since Ngong road is
a high traffic region thus it will be important during the
reconstruction of the road to work on given sections at night so
as to avoid inconveniencing many road users. This will be
during the reconstruction period after all works on the reserve
and road expansion are done to allow the road users use the new
expanded route as the existing one will be worked on.
References
Flood, K. U. (1975). Traffic management. Dubuque, IA: W.C.
Brown Co.
Olivo, L. M., & Grime, J. (2007). Traffic management. Toronto:
Emond Montgomery Publications.
Phaal, P. (1994). LAN traffic management. New York: Prentice
Hall.
Traffic management. (1991). Newton, MA: Cahners Pub. Co.

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