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UTS: 48370 Road and Transport Engineering Assessment 2

Assessment Task 2: Transport Modelling and Operations

This is an individual assignment

Please answer the following questions and present your work in a report format clearly including your name and student ID on the cover page.

Problem 1: Speed, Flow and Density Modelling using Tube Count Data (50 marks)

A traffic survey has been conducted on Gardners Road (highlighted in red), between the intersection of Botany Road and O’Riordan Street, as shown in Figure 1. The survey used automatic tube vehicle counts (pneumatic tubes) which collected speed and volume data between 6/03/2016 and 12/03/2016 (7 day survey period). The data is presented in the associated spreadsheet (“48370 Assessment Task 2 – Traffic Survey Data”).

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Analyse the provided data and answer the following questions;

  1. Within the data set are there observations where zero vehicles were recorded (Flow = 0)? Hypothetically if we did observe zero vehicle data, do we include this data in our assessment? Discuss the potential issues of including and excluding these observations within our data set. (4 marks)
  2. Determine the peak flow periods during the AM and PM time periods. What activities would create these peak conditions? Consider the surrounding land uses when answering the question. (4 marks)

For the remainder of the question, remove the observations where zero flow occurs and assess conditions for BOTH eastbound and westbound directions of travel.

  1. Determine the daily time mean speeds and the time mean speed for the entire survey period. (4 marks)
  2. Determine the daily space mean speeds and the space mean speed for the entire survey. (4 marks)
  3. Using the fundamental relationships of traffic flow and linear regression (use Microsoft Excel): (16 marks)
    1. Derive Greenshields models relating speed and density for both directions.
    2. Are the derived models a good fit for the observed data? Use a statistical measure to justify your answer.
  4. Based on the results of part c) determine the relationship between speed and flow as well as the relationship between flow and density for both directions (12 marks)
  5. Based on the Greenshields model, calculate the following properties of Gardners Road for both directions: (6 marks)
    1. Free flow speed
    2. Jam density
    3. Capacity

Problem 2: Queuing Theory and Gap Acceptance Applications (20 marks)

  1. An observer has determined that the time headways between successive vehicles on a section of highway are exponentially distributed and that 70% of the headways between vehicles are 8 seconds or greater. If the observer decides to count traffic in 30 second time intervals, estimate the probability of the observer counting exactly three vehicles in the interval. (5 Marks)
  2. At a specified point on a highway, vehicles are known to arrive according to a Poisson process. Vehicles are counted in 20 second intervals, and vehicle counts are taken in 120 of these 20 second time intervals. It is noted that no cars arrive in 20 of the 120 intervals. Approximate the number of these 120 intervals in which:
    1. Exactly four cars arrive? (2 marks)
    2. More than two cars arrive? (3 marks)
  3. A vehicle pulls out onto a single lane highway that has a flow rate of 300 vehicles/hour (Poisson distributed). The driver of the vehicle does not look for oncoming traffic. Road conditions and vehicle speeds on the highway are such that it takes 1.7 seconds for an oncoming vehicle to stop once the brakes are applied. Assuming a standard driver reaction time of 2.5 seconds, what is the probability that the vehicle pulling out will get in an accident with oncoming traffic? (5 marks)
  4. The table below gives data on accepted and rejected gaps of vehicles on the minor road of a priority controlled intersection.

    5. Gap (t) s

    Number of Rejected Gaps > 𝑡𝑐

    Number of Accepted Gaps < 𝑡𝑐

    1.5

    92

    3

    2.5

    52

    18

    3.5

    30

    35

    4.5

    10

    62

    5.5

    2

    100

    If the arrival of the vehicles on the major road can be described by the Poisson distribution, and the peak hour volume is 1100 veh/hr, determine the expected number of accepted gaps that will be available for minor road vehicles during the peak hour. (5 marks)

Problem 3: Case Study – Swiftsville Local Area Traffic Management planning (30 marks)

Swiftsville is a local government area in the little known country of Congestingvania. Congestingvania, is a country that prides itself on road safety and has the goal of developing truly integrated, sustainable and efficient transport systems. The residents of Swiftsville have alerted the authorities of a series of safety concerns within the local road network. The study area for the roads in question is presented in the map below.

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As the Traffic Engineer for the local government of Swiftsville, you are required to provide advice and design solutions for the community regarding the following concerns (listed as a), b) and c) in the proceeding pages of the brief).

For each concern;

  1. List and justify further data collection requirements or field surveys necessary to quantify and verify the residents’ claims. (2 marks)
  2. Assuming that the residents claims are verified by the additional data collected, explain and justify 2 local area traffic management solutions to ease the residents’ concerns highlighting advantages and disadvantages of each solution. (6 marks)
  3. Provide a sketch of the proposed solutions superimposed on the aerial maps provided (see “48370 Assessment Task 2 – Aerial Maps” folder within the Assignment folder on UTS Online) (2 marks)
    Cheetah Road

    Residents have complained about vehicles speeding and the number of crashes observed on Cheetah Road between Marlin Avenue and Taipan Street. Furthermore it is difficult for pedestrians to cross the road near Hare Street and Marlin Street. Below are photographs of the study area:

    48370 Roads And Transport Engineering Assessment Task img3

    Figure 2: Aerial Photograph of the Cheetah Road Study Area

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    Figure 3: Northbound view along Cheetah Road

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    Figure 4: Southbound view on Cheetah Road (towards Hare Street and Marlin Avenue)

  1. Marlin Avenue

    2. Marlin Avenue is a local street which provides access to residences, Snail Avenue and most importantly the Swiftsville Recreation Grounds. Given this context, the community has requested further facilities and a reduction in vehicle speeding to encourage cycling and pedestrian activity along Marlin Avenue.

    48370 Roads And Transport Engineering Assessment Task img6

    Figure 5: Aerial Photograph of the Marlin Avenue Study Area

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    Figure 6: Westbound View along Marlin Avenue (towards Cheetah Road)

    48370 Roads And Transport Engineering Assessment Task img8

    Figure 7: Eastbound view along Marlin Avenue (towards the Swiftsville Recreation Grounds)

  2. Turtle Way

    3. Prior speed studies have indicated that Turtle Way (between Wolf Road and Cheetah Road) has 85th percentile speeds that are 10km/hr greater than the sign-posted speed limit of 50km/hr. As a mitigation strategy, speed cushions were implemented however residents are still concerned about speeding and pedestrian accessibility along Turtle Way and are demanding remediation.

    48370 Roads And Transport Engineering Assessment Task img9

    Figure 8: Aerial Photograph of the Turtle Way Study Area.

    48370 Roads And Transport Engineering Assessment Task img10

    Figure 9: Eastbound view along Turtle Way (towards Wolf Road)

    48370 Roads And Transport Engineering Assessment Task img11

    Figure 10: Westbound view along Turtle Way (towards Cheetah Road)