Department of Transport Presentation

1
Department of Transport Presentation

• Dr. Aoife Ahern
• School of Architecture, Landscape and Civil
  Engineering
• University College Dublin
• Perceptions of Inter-urban Public Transport in
  Ireland

2
Project Description

• 2 elements to this project and 2 students funded
• Nigel Tapley
• Using stated preference techniques in modal
  choice modelling
• Gabrial Anandarajah
• Developing Optimisation Models to Prioritise
  Transportation Projects for Investment

3
Stated Preference and Modal Choice the
Objectives

• To analyse the use of stated preference models to
  look at peoples travel choices and preferences.
• Determine passengers preferences and desires on
  inter-urban public transport.

4
Stated Preference Studies

• SP studies are used extensively in the UK to look
  at value of time.
• Prior to 1987 RP was more popular.
• Very few studies of value of time and passenger
  perceptions in Ireland.

5
Routes Chosen

• Dublin Galway
• Dublin - Sligo

6
Survey Design

• Each survey had 2 parts
• RP and SP.
• Passengers were asked to complete both sections.
• Pilot study was carried out to choose variables
  and refine the survey design.

7
Main Study

• 2 types of SP questionnaire.
• Ranking and the stated choice questionnaire.
• 3 forms of stated choice questionnaire
• 5 choice set.
• 10 choice set.
• Wide-attribute questionnaire.
• The 5 choice set questionnaire was distributed on
  the Sligo train, the Sligo bus and the Galway
  train.
• The 10 choice set questionnaire was only issued
  on the Sligo train as was the wide-attribute
  questionnaire.

8
Choice Attributes

• Cost.
• Journey length.

9
Choice Attributes

• Frequency.
• Reliability.
• Presence of toilet facilities.

10
Results

• Most important attributes
• Journey length and cost.
• Frequency and reliability had expected signs but
  were not significant in modal choice.
• Modal attribute was significant only once.

11
Value of Time

• SRR - 6.63/hour.
• 10.67/hour 15.87/hour for train users.
• 11.30/hour for bus users.

12
Do People Respond in the Same Way to
Questionnaires?

• 4 SP models from Sligo train route.
• Differences in models.
• SP data from 2 different routes and modes also
  pooled.

13
Results

• Data from 5 choice and 10 choice set could be
  pooled.
• Answered questionnaires in same way.
• Sligo wide-attribute and 5 choice se could be
  combined.
• Galway and Sligo routes could be combined.
• Train and bus users also found to have similar
  decision-making processes.

14
Choice/ranking

• The choice and ranking models could not be
  pooled.

15
Developing Optimisation Models to Prioritise
Transportation Projects for Investment

• To develop investment-planning models to allow
  prioritisation of funds for improving city rail
  networks.

16
Models Used

• Optimisation models using Goal Programming
  Techniques.
• Multi-objective optimisation model to allow more
  than one optimal solution. These could then be
  ranked using the concept of an ideal solution.

17
Steps Involved

• Linear Program.
• Goal Program.
• Goal Programming Square Method.
• Multi-objective optimisation model.

18
Model 5

• Multi-objective optimisation model developed
  using the concept of the ideal solution for
  getting more than one optimal solution and can be
  used when the weights for attributes are known
  and not known.

19
Method

• The developed models were applied to prioritise
  the railway projects which were identified and
  analysed by Department of Transport (DOT),
  Ireland and were ranked for investment based on
  net present value criteria by DOT.

20
Performance of Model 5

• Matlab
• Easy for decision-makers to use.
• Only needs input data such as costs, constraints,
  attribute weights and number of optimal solutions
  needed.

21
Sensitivity Analysis

• Sensitive to user assigned weights of the
  attributes.

22
Advantages of Model 5

• More than one solution
• First best, second best etc.
• Fulfil the search for balanced solutions.