代做ITLS6102: Transport Modelling and Forecasting调试数据库编程
- 首页 >> C/C++编程ITLS6102: Transport Modelling and Forecasting
Bondi case study
Background
In this assessment you will consider the Woollahra-Waverley area in Sydney, containing the popular Bondi Beach area, see Figure 1. The Eastern Suburbs (blue) CityRail line terminates at Bondi Junction, which is a major public transport hub. There are many bus lines servicing this area. Figure 2 shows the transit lines and bus stops in the area.
Figure 1: Map of the Woollahra-Waverley area
Figure 2: Transit service lines and stops.
In the past, there have been several talks about extending the Eastern Suburbs line from Bondi Junction towards Bondi Beach. Already in 1996, the NSW government proposed a privately funded extension. However, “the proposal met with fierce opposition from local residents who were concerned with the loss of parkland, fare premium, and little potential use by residents.” (Wikipedia: Proposed railways in Sydney). In 1998, the same extension was proposed in the Action for Transport 2010 plan, see Figure 3. Again, the plan did not survive, and the extension was not realized.
Figure 3: Proposed railway lines under the Action for Transport 2010 plan (1998)
(source: Wikipedia)
With increasing developments in Bondi and increasing numbers of tourists drawn to the area with the famous Bondi Beach, the area is quickly becoming inaccessible by car. In this assessment, the idea of the extending the Eastern Suburbs line to the beach is again considered. Local residents of Waverley have asked your advice on the traffic impacts of such an extension, as they are interested to know what the potential gain for them could be, and what hinder they will face during the construction face. The focus will be on the AM peak on a weekday.
Modelling tasks
You are given three different scenarios, namely (i) the current situation (called the Base variant in OmniTRANS), (ii) the construction situation (called the Construction variant in OmniTRANS), and (iii) the extension situation (called the Extension variant in OmniTRANS). Below are brief descriptions of the data available in each variant.
Base variant
This variant represents the situation in 2023. The OmniTRANS variant provided to you contains all major roads in the area, including all bus lines and rail lines. Ferries do not contribute much to the traffic in this area, so the ferry lines are ignored for simplicity. Population and employment data are provided in the BaseCube. Productions and attractions for the external zones are assumed to be directly observed from traffic counts and split into different trip purposes based on travel surveys. They are provided in Table 1 and in an Excel spreadsheet in the ‘External data’ folder in the OmniTRANS project file.
Table 1: Trip productions and attractions for external zones
Construction variant
This variant represents the average situation in 2026. The train line extension will be underground, and instead of drilling a tunnel, Bondi Road will be partly cut open from above as a cheaper option to build the tunnel. During this construction phase, a large part of Bondi Road will only be accessible for buses. All bus lines on Bondi Road will operate as express buses with a speed of 70km/h. These network adjustments have already been made in the OmniTRANS Construction variant. The increase in population and employment is 2.5 per cent compared to the Base scenario for non-external zones. The production and attraction of the external zones is assumed to increase with 3.6 percent. The ConstructionCube in the OmniTRANS project is currently empty, such that you will have to input the relevant data.
Extension variant
This variant represents the situation in 2030. The train extension is completed, and train services now run to Bondi Beach. Several bus lines have been moved to this new train station. Bondi Road has been opened again in its original state for general traffic such that bus services can no longer use Bondi Road as an express route. These network adjustments have already been made in the OmniTRANS Extension variant. The overall population growth and employment growth is assumed to be 5.4 percent compared to the Base scenario, however, in the Bondi Beach area (zones 38, 39, 41, 42, 43, 44, 51, 52, 55) the population will increase with 14 per cent compared to the Base due to new large scale residential developments, and employment in zones 42 and 43 will increase with 15 percent compared to the Base due to new retail. The production and attraction of the external zones is assumed to increase with 6.7 percent, except for zone 13 (external railway zone), which is assumed to see an increase of 10.5 percent. The ExtensionCube in the OmniTRANS project is currently empty, such that you will have to input the relevant data.
Job scripts
Four job scripts are available to you in OmniTRANS. First, inspect the Project Setup and the different dimensions in the project, the link types, and the zonal data. Then carefully inspect each job, in particular the dimensions used, and the parameters set for different methods. You do not need to change any of these jobs. Each job can be run in each variant (make sure the relevant variant is selected – highlighted in grey – before pressing run). The output data (skim matrices, OD matrices, link loads) are then stored in each variant and the corresponding matrix cube. Below a brief description of each job.
1. Generateskim matrices
With this job, travel time skims based on free-flow conditions are generated for car and public transport (including waiting/transfer time). In this project we are not concerned with intrazonal traffic, hence skim factors will be set to 99999 for intrazonal traffic such that a zero demand will be generated in the trip distribution step. Further, traffic between certain external zones are not of interest, and therefore some skim values are set to a larger value to avoid much traffic between external zones, and some are set to 99999 to avoid any traffic between them.
2. Trip generation
With this job, based on population and employment data, the trip production and attraction are determined for two different purposes, namely work and other, each being either home-based or non-home-based. The trip production and attraction are determined using linear regression models with functions provided in the script.
3. Trip distribution and modal split
With this job, a simultaneous trip distribution and modal split is performed using the trip production and attraction data and the free-flow travel time skims for each trip (sub)purpose, which will generate an OD matrix for the car and an OD matrix for public transport. Exponential deterrence functions are assumed, and the trips are balanced towards the productions.
4. Trip assignment
With this job, trip assignment is done for cars, buses, and trains. It is assumed that each car is occupied by a single person. Outcomes are link loads for cars, buses and trains, and skim matrices with congested travel times (except for trains, they are assumed to run without delays). For car assignment, a deterministic user equilibrium is found using BPR travel time functions. For bus and train assignment, a multi-routing algorithm is used to allocate the passengers over different transit lines, with walking as access and egress mode. Buses take congestion on the roads into account.
Your assignment
You are asked to advise the local residents of Waverley how the traffic situations will change during the construction phase and in the final situation with the railway extension. To this end, you will make transport prognoses of the construction phase and detect any potential problems, and who will be mostly affected. For potential problems you detect, you are asked to provide at least one solution (by means of modifications to infrastructure or public transport services) in a new alternative variant that mitigates the problems during construction (a Mitigation variant for this purpose is available in OmniTRANS). You will also need to determine the impact of the solution(s) (supported by model calculations) using several self-defined criteria. Further, you will analyse the end situation with the railway extension and its benefits and possible disadvantages. You are asked to describe your findings in a formal report and provide a final recommendation to the local residents regarding any possible adaptations to be considered by Waverley council if their plan comes to fruition. The due date for this report is provided on Canvas.
Report and marking
You are asked to write a report of maximum 3,000 words (excluding reference list, appendices, tables, and figures). You are expected to work alone and submit the report via Canvas. A template is provided for the report to provide you with some structure for your report. The report will be assessed in a similar way as in the previous assessment, with a focus on numerical and graphical analyses of the different variants, descriptions of the models (methodology) and data, conclusions, reporting style. and overall quality of the report. A critical assessment of the model and its limitations is expected as well. Therefore, an important part in your report is a critical thinking section describing some possible model improvements (there are several unrealistic assumptions in the model).
Penalties
• Late submissions: reduction of 5 points for each day after the due date
• Exceeding word limit: 10% is allowed, reduction of 5 points for each 10% over the limit afterwards
Marking criteria
Criterion |
Weight |
Mark depends on to what extent … |
Problem description, |
30% |
• context, aim, scope, and data are discussed |
methodology, |
|
• applied methods and used parameters are properly described and interpreted |
critical thinking |
|
• model improvements are proposed and justified |
Scenario analysis |
50% |
• the inputs/outputs for the base variant 2023 are provided and interpreted • the impacts and results of the construction in 2026 are analysed and discussed • the impacts and results of the train line extension in 2030 are analysed and discussed • a problem mitigation variant during construction is proposed and justified • the impact of the problem mitigation variant is compared to the construction scenario using suitable criteria |
Writing and presentation style |
20% |
• high quality tables and figures are provided • the writing exhibits a clear structure, narrative, and conclusions/recommendations for the target audience |