UCD School of Civil, Structural and Environmental Engineering

Current Projects:

• Urban Environment Decision Making: Integrating decision making models
• Investigating the complexity of commuter travel decisions using the Theory of Planned Behaviour

Completed Projects:

• A study of area-based approaches to urban regeneration: a case study of historic area rejuvenation project
• Examining methodologies for designing transport strategies for developing cities - case study: Tripoli
• The use of stated preference techniques in modal choice modelling
• Developing Optimisation Models to Prioritise Transportation Policies for Investment

Current Projects

2006-2009, Urban Environment Decision Making: Integrating decision making models
A. Ahern

Moland is a state of the art land use model that has been pilot tested in the Greater Dublin area using 2000 data.

The model has two main components, namely a regional sub-model and a detailed land use sub-model. In the current Moland model, counties are regarded as regions and it models demographic, economic and transportation interactions between these counties. National data such as population growth and GDP expansion are inputs into the regional sub-component.

Data from the regional sub-model feeds into the land use sub-model ('micro model') which allocates a land use to each grid cell. This sub-model can in principle run at any level of spatial resolution (eg grid cells of 20x20m, 100x100m etc). It allocates land uses through a process called Cellular Automata (CA). The CA process uses a variety of inputs to determine the land use in any particular grid cell, including rules which indicate how compatible land uses are with each other. Random factors as well as trends and stable interrelationships between land uses can be factored into the scenario generation process, as well as new infrastructure and land use zonings.

Moland provides output on an annual basis into the future. Obviously the further into the future the projections are made the less accurate the projections are likely to become.

2003-2007, Investigating the complexity of commuter travel decisions using the Theory of Planned Behaviour
A. Ahern

This project examines the complexity of travel behaviour, in particular commuter travel behaviour. It is hypothesized that the decision-making processes of commuters are extremely complex and that factors such as attitude, subjective norm, perceived behavioural control and habit need to be examined when looking at people's commuter travel patterns when implementing policies that attempt to change those travel plans. Two companies in Dublin are involved with this study and commuters from these companies have been interviewed at length regarding their travel choices.

Completed Projects

2000-2001, A study of area-based approaches to urban regeneration: a case study of historic area rejuvenation project
A. Ahern

This project examined the impacts of new public transport infrastructure on areas in Dublin which were ear-marked for urban regeneration.

2002-2004, Examining methodologies for designing transport strategies for developing cities - case study: Tripoli (funded by the Govermnent of Libya)
A. Ahern

In many cities, the design of transport strategies takes place after traffic and congestion problems have arisen. In this project, it is proposed that cities in the developing world should learn from cities in Europe and the States by pre-empting these problems and putting in place transport policies and strategies. The project describes how the city of Tripoli in Libya can go about putting in place a transport strategy for its future development. The project describes some studies and strategies of cities in the UK and Ireland and describes what lessons can be learnt. In particular, the project finds that strategies need strong political backing if they are to be successful and they need clear leadership. The project concludes that strategies should be used to prevent problems rather than to solve them and that the success of any strategy in Tripoli will be reliant on proper funding and strong decision-making.

2003-2005, The use of stated preference techniques in modal choice modelling (funded by the HEA and Department of Transport)
A. Ahern

The primary purpose of this study is to analyse the use of stated preference techniques in modal choice modelling. One of the primary uses of SP techniques is in the valuation of modal attributes (e.g. travel time, cost reliability etc.) and their relative importance to individuals. Thus, the estimation of these modal choice models may also provide valuable information regarding the perceptions and preferences of respondents. Accordingly, in order to maximise the benefits of this analysis, the choice of an appropriate study context was also an important element in the design of the study.

Between 1970 and 1995, car use in Europe more than doubled, rising from approximately 4500km per year per person to over 9000km per capita. During the same period, the use of public transport remained relatively static, averaging less than 1000 km per capita for both rail and bus. By 1995 approximately 80% of passenger kilometres in the EU were by car. Both increasing economic activity and changes in transport costs have been cited by experts as the reasons for this increase in car use.

Ireland in particular has seen a growing reliance on the car as a means of transport. By 1995, the average annual travel distance by car in Ireland was 15% above the EU average, while the average annual distance by train was the lowest in Europe at approximately half the EU average. The economic success of the mid to late nineties saw the number of new cars registered in Ireland grow from 77,773 in 1994 to 138,538 in 1997. This increasing reliance on car use have led to decreases in the efficiency of the economy together with increases in the use of non renewable resources and increases in pollution and waste levels. Perhaps the most noticeable effect of this increased demand for car use is the increased levels of congestion that accompany it. Ireland has experienced an increasing imbalance of supply and demand for road space, particularly during the last ten years. Increased car use on the road network has led to slower and less reliable journey times, increasing levels of pollution and an increase in accident rates. Thus a major goal of the Irish Government's current transport policy is the reduction of car use in favour of a modal shift towards public transport use, thereby reducing the demand for road space.

Ireland's interurban rail network has been identified as being in particular need of large financial investment if it is to become more appealing to users. This is a result of years of under-investment in the network, which has led to deterioration in the quality of the rail service. While the deteriorating rail network has become the main focus of investment, Ireland's interurban bus service, run by Bus Eireann, has also experienced a decline in user satisfaction in recent years. As a result, funds have also been hypothecated to improve service quality on this network.

In this case, the current levels of investment in Ireland's public transport infrastructure have generated an increased interest in determining passengers' preferences and desires. This renewed interest in travellers' perceptions is borne from the desire to maximise the benefits of the current financial investment. Thus, an interurban public transport context was chosen as the basis for this study. It was hoped that the results of this analysis would allow for a greater understanding of the perceptions of public transport users in Ireland.

2003-2006 Developing Optimisation Models to Prioritise Transportation Policies for Investment (funded by the HEA and Department of Transport)
A. Ahern

This project looked at developing optimisation models to prioritise investment in railway projects in Ireland. This research developed new methods of optimising which allowed projects to be ranked. It examined the impacts of railway investment on land use, the economy and society can be incorporated into models that determine where investment should be focussed.

The steps involved included producing a linear program at first, followed by a goal program and finally a goal programming square method. The goal programming square method allows planners to examine different criteria for investment and ranks project in order of priority for investment. It is a very flexible tool that can be used to look at investment in road projects in addition to rail projects and that can be adjusted to allow for different criteria to be modelled.

The study showed that projects can not be analysed independently when determining levels of investment. The project also determined that intercity rail demand is elastic with price and that policy makers should subsidise train tickets in order to increase passenger numbers. It was found that in the long-term if ticket prices were reduced by 1%, passenger journeys would increase by 1.08% in the long-term. A reduction of 5% in ticket prices would increase revenue by 0.12% and a reduction of 10% would increase revenue by 0.3%.