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Unformatted text preview: GUT Student Number Surname Given Name/s Examination Paper SEMESTER: SECOND SEMESTER EXAMINATIONS 2005 UNIT: CEB323 TRANSPORT ENGINEERING 1  THEORY 1 DURATION OF EXAMINATION: PERUSAL: 10 MINUTES
WORKING: 3 HOURS EXAMINATION MATERIAL SUPPLIED BY THE UNIVERSITY:
EXAMINATION BOOKLETS GRAPH PAPER 2MM
DATA  FOUR (4) PAGES ATTACHED EXAMINATION MATERIAL SUPPLIED BY THE STUDENT: WRITING IMPLEMENTS '
CALCULATORS  NON PROGRAMMABLE INSTRUCTIONS TO STUDENTS: Students are prohibited from having mobile phones or any other device capable of communicating information
(either verbal or written) in their possession during the examination NOTES MAY BE MADE ONLY ON THE EXAMINATION PAPER DURING PERUSAL TIME
FIVE (5) QUESTIONS ONLY ARE TO BE ATTEMPTED, OF WHICH QUESTION 1 IS COMPULSORY
PLEASE COMMENCE EACH QUESTION ON A NEW PAGE ALL QUESTIONS ARE OF EQUAL VALUE THIS EXAMINATION PAPER MUST NOT BE REMOVED FROM THE EXAMINATION ROOM Queensland University of Technology GUT GUT Gardens Point Kelvin Grove l Commence each question on a new page in the examination booklets. QUESTION 1 (20 marks) (a) (b) (C) (d) Respond brieﬂy to two (2) only of the following four items: (i) With the aid of a diagram identify two sources of moisture movements in road
pavements and state the consequence of moisture on pavement performance. (ii) What is stabilization and why is it used in certain pavement construction? (iii) What is the California Bearing Ratio and how is it measured in the ﬁeld? (iv) What is the subgrade failure criterion and how is subgrade failure evident on the surface?
(4 marks)
Respond brieﬂy to two (2) only of the following four items:
(i) Explain how shear strength is developed in unbound granular pavement material. (ii) Identify the dominant distress modes in cemented pavement material.
(iii) Identify two naturally acquired material types that can be used as unbound granular pavement material. (iv) Identify two factors that decrease stiffness in asphalt as a pavement material.
(4 marks) The Main Roads Department wishes to design a ﬂexible pavement consisting of granular
material and asphalt wearing surface for a 20 year design life for a two lane section of the
National Highway between Brisbane and Sydney (Functional Road Classiﬁcation 1).
The current two—way AADT is 4,300 including 9% commercial vehicles. The desired
initial roughness is 50 counts/km. Trafﬁc growth has been at the rate of 3.5%p.a. over
the past ten years and is assumed to continue. Using Tables 7.2, 7.4, E5, and Figure 7.2,
calculate the modiﬁed design traffic .(ESAs) for this pavement design. For which case
would the modiﬁed design trafﬁc be used in a pavement design instead of the initial design trafﬁc?
(6 marks) A subgrade has a dynamic cone penetration of 28mm/blow. Use Figure 5.2 to establish
its support. Based on this support select the appropriate design chart from those provided
(ECll or EClZ) to design a pavement of asphalt on cemented material (cracking not
acceptable) for a design trafﬁc of 9*106 ESAs. You may assume that asphalt costs
$200/m3 and cemented material costs $85/m3 (both placed) in order to determine the
optimal proﬁle. State all assumptions made in determining you final pavement profile.
If you were to accept that cracking of the cemented material may occur during the pavement’s design life, describe how you would make allowance for this in the analysis.
(6 marks) CEB323T1.052 cont/... QUESTION 2 (20 marks) (a) Describe three different barrier types and comment on where they should be used. (8 marks) (b) A signalised intersection has the following movement data. Movements are numbered
around the compass in the conventional manner. Movement Starting Phase Terminating Arrival Flow Saturation
Phase (veh/h) F low (veh/h)
1 B A 125 1,500
3 C A 375 1,650
5 A B 935 3,400
l l A C 875 3,600
12 B C 125 1,600 Lost time for all movements is 6s and intergreen time 55.
Practical degree of saturation for all movements is 0.90.
Minimum displayed green time for all movements is 65. Note it =y/d7, t=g+l, g = uc, y = 51/3 Respond to the following: (i) (ii) (iii) (M (V) (vi) CEB323T1.052 Draw the phase diagram for the phasing scheme set out in the table above.
(2 marks) _ From the information above calculate trial movement times for each movement under an initial 605 cycle time.
(2 marks) Draw the critical movement search diagram and identify all possible critical
paths. Identify the critical path. Identify whether the initial cycle time is sufﬁcient.
(2 marks) If the initial cycle time is sufﬁcient, reapportion the critical movement times to
suit the cycle time stating your policy. Otherwise, identify a revised cycle time that is sufficient and recalculate critical movement times accordingly.
(2 marks) For your cycle time result from (iv), assign the noncritical movement times.
(2 marks) Calculate the degrees of saturation for all movements and discuss how the intersection would perform under these conditions.
(2 marks) cont/. .. QUESTION 3 (20 marks) (a) (b) (C) (d) (6) Describe each of the four steps required to undertake travel demand modelling for an urban area.
(4 marks) What is meant by model calibration?
(4 marks) Data on travel behaviour is required to build travel demand models for each of the four steps. What type of travel behaviour data is needed and how might it be collected?
(4 marks) What are the two main types of errors which can be expected when using four—step travel demand models to forecast future trip making?
(4 marks) How would you expect those two types of errors to be related to the complexity of the models? Complexity here is deﬁned in terms of the number of variables used.
(4 marks) CEB323T1.052 cont/... QUESTION 4 (20 marks) (a) A household linear regression model has the following form: P=a0+a1X1+a2X2+a3X3 Where P is the number of total trips/household/day and X1, X2 and X; are three
explanatory variables. (i) How can we estimate the coefﬁcients of that equation? (ii) List three possible variables for this model.
(8 marks) (b) The gravity model for trip distribution has the following form: T“ : PiAfi.
U ZAjfij
i Explain what each term of this equation means.
(4 marks) (0) One of the most common formulations for mode choice models uses the concept of
generalised cost of travel and a logit curve. ‘ (i) Explain what is generalised cost.
(ii) Explain the 'logit form of a mode choice model where the only choices available are car and public transport modes.
(8 marks) CEB323T1.052 cont/... QUESTION 5120 marks) (a) A two lane roundabout is proposed to control trafﬁc at the junction a four lane divided
arterial road running eastwest and a two lane subarterial road terminating at the south
approach. In your workbook describe by way of illustration suitable concept geometry of
this roundabout including lane allocations and discipline, traffic control measures, road
safety considerations, and functionality considerations. (6 marks)
(b) Using the origin destination data at a single lane, four approach roundabout: To Leg/ South East North West
From leg South 5 10 210 15 East ll — 23 370
North 350 9  21 West 21 190 27 — Calculate the entry capacity of the East approach, assuming that the circulating stream
headways have a Cowan relationship. Also assume that: a A(T~A) A=25, 7:4.3 8, rﬁd0m=22 s, a=o.75(1q,), A: ‘16 , gem“ 30211:...
1‘ch ‘ I l~e_ll~" (8 marks) (c) The probability that exactly x vehicles arrive during a time interval of t seconds at a trafﬁc
ﬂow rate of q veh/s can be estimated using the Possion Distribution as follows: 6““ (610" pm = ,
x. where the mean number of arrivals during time interval, t, is equal to qt. Using this
distribution of arrivals as a basis: (i) Derive the negative exponential headway distribution in its cumulative form.
(ii) Using the graph paper provided draw the negative exponential headway distribution
in cumulative form, to a maximum headway of 255, for a ﬂow rate of 0.2veh/s.
(6 marks) CEB323T l .052 contl. .. QUESTION 6 (20 marks) (a) During the morning peak hour a three lane section of motorway upstream of a merge area
experiences a trafﬁc ﬂow rate of 4,700veh/h. A further 700veh/h enters the motorway at the
on—ramp, which tapers off, thus a three lane section also exists downstream of the merge
area. The motorway is on rolling terrain (ET = 3.0) and has an estimated free flow speed of
lOOkm/h. The peak hour factor is 0.95. The population factor is 1.0. Of all trafﬁc trucks
and buses constitute 10 percent and there are no recreational vehicles. FlG URI! 34. LEVEL OF SERVICE C RIT ERIA ILLUSTRATED With respect to this chart from the Highway Capacity Manual (1997) respond to the
following: (i) Explain the signiﬁcance of trafﬁc density in motorway level of service analysis. (ii) Determine the level of service on the mainline segment upstream of the merge‘ area. (iii) Determine the level of service on the mainline segment downstream of the merge
area. (iv) Using your analysis results qualify the operation of the motorway in the vicinity of
the merge are during the morning peak hour. (8marks)
V v
: ;V : ;D——._..£_
f‘” 1+P7.(ET—l)+PR(ER—l) " PHFxNfofoP S — Question 6 continued overleaf — CEB323T1.052 cont/. .. — Question 6 continued  (b) Referring to the sketch below of an unsignalised T junction, respond to the following
questions in a table in your workbook. Legend
12 Movement number
(xxx) Movement flow (veh/h) 7 f (180) (240) (i) Identify the priority level of each of the movements shown, and the priority level
of each movement’s conﬂicting movement/s. (2 marks) (ii) Determine the equivalent opposing flow for each movement neglecting baulking. (2 marks) (iii) Using Table 13.12 below select the appropriate critical gap and follow—on time
for each movement. ' (2 marks)
(iv) Calculate the capacity and degree of saturation for each movement. (2 marks)
(v) Calculate the capacity and degree of saturation for each approach lane. (2 marks)
(vi) In words, qualify the unsignalised intersection’s operating perfOrmance. (2 marks) 1 q e“’"T’ 1
a: q+ __ 111(1‘X2); qmax r :—a_—1_; qmaxz n
(I ; EC] T3 ; .P3 1—8 ‘lufﬂi f;
1:! qmaw‘ — Question 6 continued overleaf — CEB323T1.052 cont/...  Question 6 continued  Diagram Two iane .1 one way Three lane / one way F ur lane lone way “(we Rana / twa way F0 ‘iane / two way
‘" lane: / two way b) h Lu \) 073301013?!) (:1 m
(D '3
" (I! l (‘1 Right Hand Turn from , : 5 Across ‘r fans:
majar road , Q 5 ‘ Acrcsg 2 lanes
Across 3 {anes (J3 4‘.
(/7 J)
' (l)
0
m n m
n . (/1 c: It} (a
, 02 1;:
(1 0
m g
i
l (,5
l4
( and Turn from i ' . nten‘en‘ng with A
minor road ;‘ ‘ One way
’ Two lane / two way
Fourtane / two way
Six iane I two way 2:: U! m {,3
m m m
(1': w m 0 0 (I r: 0 (/7
(b in” ; Note: 1(a) = Cn'ticai accep!ance gap. (,5 = foi/cw Ls headway fable 13.12 Gap Acceptance Time END OF PAPER CEB323T1.052 (i) JULY1992 SUBGRADE EVALUAUON inIIII IIIIIIIIIIIIIII
IilllIIIIlIIIIIIIll :Illilllllllllllllll
IIIIIIIIIIIIIIIIII In Situ 15'
California Bearing
Ratio We) 10 IIIIIIIIIIIII
=:IIIIIIIIIL‘IIIII IIIIIIIIIIIIIIIIIII
:IIIIIIIIIIIIIIIIII
IIIIIIIIIIIIIIIIII IIIIIIIIIIIIIIIIIII
IIIIIIIIIIIIIIIIIEII
20 40 80 100
Penetration (mm/blow) , FIGURE 5.2 CORRELATION OF DYNAMIC CONE PENETRATION AND CBR CEB323T1.052 (Ii) JULY 1992 DESIGN TRAFFIC TABLE 7.4 VALUES OF TERMINAL ROUGHNESS NAASRA Road Terminal Roughness
Functional Class‘ NAASRA counts per km 1and2 110
Bands 150
4, 5. 7, 8 and 9 175 1 For definition of Classes see Appendix A I Ratio Terminal/Initial Roughness Modified.
Design
Traffic Design Traffic (ESAS or Standard Axles) FIGURE 7.2 MODIFIED DESIGN TRAFFIC VS DESIGN TRAFFIC AND FIATIO FINAL/ INITIAL FIOUGHNESS
(FOR USE IN DESIGN OF NEW FLEXIBLE PAVEMENTS) CEB323T1.052 (111) E4 PAVEMENT DESIGN JULY 1992
TABLE ES
NUMBER OF ESAS PER COMMERCIAL VEHICLE ACCORDING TO STATE AND ROAD FUNCTIONAL CLASS
(FACTOR F) Road State/Territory Functional
Class 1 WA SA 1 Road Fu'nctional Classes are defined in Appendix A
E: Extrapolated from 1973 survey data TABLE 7.2 CUMULATIVE GROWTH FACTORS (GF) Growth Rate (% pa) 5.2 5.4 5.5 5.9 5.1
10 10.9 12.0 13.2 14.5 15.9 15 17.3 20.0 23.3 27.2 31.8
20 24.3 29.8 35.8 45.8 57.3
25 32.0 41.5 54.9 73.1 98.3
30 40.5 55.1 79.1 113.3 154.5
35 50.0 73.7 111.4 172.3 271.0
40 50.4 95.0 154.8 259.1 442.5 CEB323T1.052 8.15 ., Thickness Thickness
of
Asphalt
(mm) CEB323T1.052 UV) . » PAVEMENT DESIGN EC 11 EXAMPLE DESIGN CHART 11 500
Thickness of Cemented Material (mm) NOTES 1. Allowance to be made for construction tolerances 2. For pavements where the cover over the cemented
material exceeds 100mm the second phase of life
of the pavement after the cracking of the cemented
material may be considered. For guidelines see Sec. 8.5 EC 12 EXAMPLE DESIGN CHART 12 JULY 1992 Asphalt Mod. 2800 MPa Cemented
Material Mod. 2000 MPa 7777777—
CBR 5 Dominant Distress Mode: : Fatigue of
: Cemented Material 3 Fatigue of
3 Asphalt Asphalt IIIIIIIIIIIIIIIII M..___°d 289.0. MPa Cemented
Material II=IIIIIIIIII Mod 2000 We  Wﬁ
kﬁﬁﬁﬁﬁﬁﬁﬁ
IllII ﬁﬁﬁﬁkﬁﬁﬁﬁﬁﬁﬁﬁ
IIIIII§$$§W§§$§Q§%§§
IIIII  :;;; ﬁﬁﬁﬁﬁﬁﬁﬁﬁﬁﬁﬁﬁ
OIIIIIIIIIIIIIIIIIIII 300 400
Thickness of Cemented Material (mm) NOTES 1. Allowance to be made for construction tolerances 2. For pavements where the cover over the cemented
material exceeds 100mm the second phase of life
of the pavement after the cracking of the cemented
material may be considered. For guidelines see Sec. 8.5 7777777—
CBR 7 Dominant Distress Mode: Fatigue of
Cemented Material 3 Fatigue of
‘ Asphalt ...
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