Road and street engineering

CIV5704 – Road and Street Engineering

Assignment 2

Description Marks out of Weighting (%) Due date

Assignment 2 200 marks 20% 10 October 2016

Rationale

This assignment is designed to test your achievement of the learning objectives of Modules 1 to 9.

Special instructions:

Assignment 2 must be submitted by the due date via the StudyDesk link as an attachment (word or

scanned pdf file). No emailed, faxed, photographed or hard-written copy of assignment submissions

will be accepted.

Information provided is generally adequate to complete the questions. If any assumptions are

required, those should be clearly stated. The answers should be well set out and clearly shown,

including all required calculations, estimations of qualities of road construction materials, etc.

No Microsoft Excel files will be accepted as a part of your calculations.

Responses are not to be structured like a formal report. Rather, clearly present your answers (typed

i.e., no hand written) in a format appropriate to a student presenting answers to examination questions.

Penalty for late submission of Assignment 2

Please note that the onus is on students to organise their affairs so that they can achieve the

educational objectives of the course and submit assignments for assessment no later than the due date.

Work commitments will not be considered a legitimate reason for late assignment submission.

If students submit assignments after the due date without legitimate and extenuating circumstances

(e.g. illness substantiated by a medical certificate) then a penalty of 5% of the assigned mark may

apply for each working day late up to a maximum of ten working days at which time a mark of zero

can be recorded for that assignment.

Problem 1 – Module 5 – Road safety analysis

The following helps to critically analyse the data from common traffic engineering studies to

improve road safety.

Your task:

(a) Research the problems associated with aged drivers in the road transport system by

selecting one particular aspect against your first letter of your surname from the list

below:

Topic First letter of

your Surname

Older drivers’ crash involvement – Research and document

contributing factors and your discussion supported by statistical

data representing their crash involvement

D, G, T, H

Licensing issues with older drivers – Identify various issues

assassinated with licensing older drivers; and collect suitable

strategies adapted to dissolve them.

Q, U, Z, B

Alcohol and older drivers – Highlight the current status and

discuss the contributing issues and propose countermeasures for

improvements

J, K, M, L

Older drivers’ physical or mental capabilities – Document the

recent findings from the research and investigation carried out on

older drivers capabilities related to their physical and mental

conditions

A, N, P, Y

Older drivers’ reaction times – Highlight the reaction time

between different age group to surface the problem and document

the strategies that can be adapted in road design to improve overall

road safety. Read recent research articles to document the relevant

S, V, F

Road safety for older drivers as pedestrians – Collect the

finding from research reports to document the crashes involving

older drivers as pedestrian. In addition illustrate example of

appropriate road infrastructure for reducing similar crashes.

W, C, E, I

Security issues for the elderly when using public transport –

identify the challenges for the ageing society when using public

transport, and develop strategies to develop meaningful

recommendations for the public transport authorities to develop

further actions

R, X, O

Examples:

If your name is ‘James HICKS’ then your topic will be “older drivers’ crash involvement”

You are expected to consult a number of sources on the aspect you investigate.

(b) Provide details on the aspect which you have chosen in (a) above. Your arguments

should be 600 to 900 words in length (not including references, which of course should

be part of your arguments). The arguments should clearly identify the following:

1. The title of the aspect. 2. Collection of background information to highlight the need for your given topic with

suitable sub-headings (400 words)

3. A summary of major issues which arose during your literature search, and your recommended strategies for reducing the effect (500 words).

4. A full citation of the paper as it would appear in the USQ’s Harvard referencing system.

(40 Marks)

Problem 2: Module 5 – Road safety analysis

An intersection has a crash rate of 12.6 per 40 million entering vehicles. The database for all similar

intersections in the area indicates an average crash rate of 24.5 per 100 million entering vehicles with

a standard deviation of 3.2 per 100 million entering vehicles.

Should these intersections be reviewed for road safety improvements at the 95% confidence level?

(15 Marks)

Problem 3: Module 5 – Road safety analysis

An engineer observed that 6 consecutive kilometres of a rural highway had the following number of

serious crashes per year:

Km No 1 2 3 4 5 6

Total number of

crashes 54 65 62 57 63 60

These highway sections have similar geometric features for carrying equal volume.

Use Chi-square test to examine the condition whether is there any evidence to show that location

make differences for a level of 5% significance.

(15 Marks)

Problem 4: Module 6 – Traffic signals design, control and analysis

A single lane approach at a signalised intersection operates with 30 seconds of green period.

Observation was started at time t=0 (with the start of green time), and the time of all vehicles

leaving stop line of an intersection approach were entered into the table below.

Vehicle number 1 2 3 4 5 6 7 8 9 10

Time of passing (sec) 4.55 8.02 10.89 13.54 15.89 18.14 20.44 22.69 24.91 27.13

1. Calculate the average headway of the vehicles 2. Determine the saturation headway for the approach, hence calculate the saturation

flow rate in vehicles per hour

3. List the factors affecting the saturation flow rate at a signalised intersection approach.

(20 Marks)

Problem 5: Module 6 – Traffic signals design, control and analysis

The following table details the traffic flow at four-leg intersection.

Assume a three phase timing plan as shown in Figures 1 and 2 is suitable, with 3 seconds of amber

time and all read time is 2 seconds. Total lost time per phase is 5 seconds including start and end

losses and all red times.

1. Using Webster’s equations, determine the optimum cycle time and green split time, and

provide timing diagram for your design (without considering pedestrian movements).

2. Propose a suitable arrangement/solution for pedestrians to cross the roads at intersections.

Lane 1 2 3 4 5 6 7 8

Volume (vph) 500 200 374 55 336 115 370 60

Saturation Flow rate

(vph) 1650 1500 1700 450 1600 1450 1850 550

Figure 1: Four-leg intersection

Phase 1 Phase 2 Phase 3

Figure 2: Three phase plan

(30 Marks)

Problem 6 - Module 6 & 7

Traffic flow on two-approaches at a four-leg intersection is given below:

Approach Traffic flow

(vph)

Saturation flow

rate (vph)

Cycle time

(sec)

Effective red

(sec)

NB 336 1600 120 78

EB 370 1850 120 75

Assume that arrivals are uniform throughout the cycle, and D/D/1 queuing is applicable.

Determine the following for each approach:

a) The time to queue clearance after the start of the effective green

b) Proportion of the cycle with a queue

c) Proportion of vehicles stopped

d) Maximum number of vehicles in the queue

e) Total vehicle delay per cycle

f) Average delay per vehicle

g) Expected maximum delay for any vehicle

[Calculate and report your answers to 3 places of decimal, e.g. 0.0933333 v/s, to 0.093 v/s]

(20 Marks)

Problem 7 - Module 6 & 7

The signals at the intersections (from A to D) along the two-way street have been pre-timed

as shown in table. The posted speed is 50 km/h. Determine the width (if any) of through-band

(bandwidth) in each direction of the two directions and show the through bands on a

progression diagram.

Intersection Distance

from A

Green

(sec)

Y + AR

(sec)

Red

(sec)

Offset

(sec)

A 0 40 5 15 0

B 134 35 5 20 5

C 420 35 5 20 5

D 688 40 5 15 40

Y – Yellow time; AR – All-red time

(30 Marks)

Problem 8 – Modules 1-9 – Transportation system management (TSM)

1. Identify an ITS project or application that is underway in your hometown or nearest

city.

Provide the details about your ITS project; your details should be limited to a

maximum of 700 words in length (not including references, which should be part of

your response).

Your detail description should clearly identify the following:

 The title of the ITS project.

 Description of the project including its purpose and the ways that it was planned

and designed, and how it is operating now. Suitable background study can be used

to support your description (400 words)

 A summary of major advantages and disadvantages that can be or have arisen due

to the project, and your recommended strategies for minimising disadvantages or

negative effects (300 words).

 A full citation of the paper as it would appear in the USQ’s Harvard referencing system.

(30 Marks)