After almost fifteen years of unprecedented economic growth, the Irish economy is now experiencing one of the largest declines experienced by any developed country since World War II [1
]. After an export-led boom that was fuelled by large increases in productivity per capita
in the last years of the 20th century and the first years of this one, recent economic growth was largely driven by the construction of housing units. Ireland experienced perhaps the largest expansion in housing supply of any economy in Europe. The number of units built annually peaked at 88,000 in 2007 which translated to 18 units per 1000 people, more than three times the average rate for eighteen other European countries measured [2
]. In tandem with this, house prices increased by 65% and the amount of total mortgage debt almost trebled to €140B between 2002 and 2007, reflecting an increased demand and a doubling in the average loan size for new mortgage holders [3
In that period, Dublin, as capital of Ireland, was an economic driver and the area, like the rest of the country, underwent significant economic and demographic changes with increases in employment, income, and population. Already a low-density city by European standards [4
], rapidly increasing house prices (along with other pressures such as road congestion and demand for oversubscribed services) incentivized developers and potential buyers to locate further from the traditional Central Business District (CBD) [5
]. What is more, the nature of local government in Ireland further incentivized development activity. Local authorities, with little power to levy taxation on property or land, engaged in large-scale rezoning’s as a way to raise additional revenue through development levies [6
]. These pressures led to rapid development activity and population increases beyond the traditional boundaries of the city and are changing the relatively monocentric nature of the City [7
]. Consequently, the population of the Greater Dublin Area (GDA), an area defined as the four counties of Dublin and the three adjacent counties, increased by 20% between 1996 and 2006 while the numbers in employment increased by almost a half with the largest increases occurring outside Dublin City [4
In tandem with the increases and dispersion in economic and settlement activity, transportation patterns also changed significantly. Firstly, the oft-reported relationship between economic growth and increased car ownership was particularly pronounced in Ireland [8
]. While Irish car ownership levels, at 437 cars per 1000, remains slightly below the European Union average of 463 in 2007 [9
], the number of registered private cars has almost doubled since 1996, standing at 1.9 million cars in 2007, of which the GDA accounted for some 720,000 cars [3
]. This increase in car ownership was also reflected in a larger share of GDA commuter trips (which are defined as trip to work, school or college) undertaken using cars, increasing from under 47% to almost 52% in the 10 years to 2006 [4
]. The combination of increasing economic and transport activity, dependence on car travel and the diffusion of settlement patterns are all closely interrelated. Other researchers have found that mode choice and transit usage are impacted primarily by density and land use [10
]; in Ireland both variables are largely defined by policy decisions (e.g., through zoning). Distance from the central business district is also an important determinant of mode choice [11
]. Similar to other economies, these interrelationships have resulted in worsening congestion and environmental performance as the private cost of motoring is often less than the costs imposed on society, especially in urban areas [12
]. Not only have travel speeds decreased for road commuters, with the possible exception of the City’s network of Quality Bus Corridors [13
], carbon dioxide (CO2
) emissions from transport increased by almost 170% between 1990 and 2006 in Ireland [14
With the city and the country undergoing a significant economic reversal, it is perhaps an appropriate time for researchers to conduct an overview of the boom’s impacts on transportation patterns for the Dublin area. As Scott [15
] notes when questioning if longer journey times were the result of current government policy, planning laws need regular assessment in terms of their effects. In this research the authors focus on the residents living in the four counties that make up Dublin city and county. Data from the 2006 census is used to analyse how transport patterns differ based upon some key housing and land use characteristics, such as the number of public transportation options available, density and the year of housing construction. With this last variable, the authors want to explore how commuting patterns differ, if at all, as a result of the housing age, holding all else equal, from those living in housing units constructed in earlier periods.
The paper is outlined as follows: in the next section there is a short review the policy context for our research question by outlining some of the stated transportation and sustainability goals of the Irish government and review the relevant academic literature. The following section outlines our methodological approach for answering our research question. The results of the research are presented in the last section of the paper. The paper concludes with an overview of the results and a policy discussion.
2. Policy Context and Literature Review
The Irish government have outlined a number of very ambitious strategies in the transportation and sustainability realms for both the medium and long term. In the transport sphere, response has generally taken two forms—infrastructural (increased road capacity by widening and expanding the road network, provision of additional heavy rail capacity, light rail, bus priority, etc.
) and demand side management aimed at tackling congestion (parking pricing, transportation allowances, transit and rideshare financial incentives, public transport pass programmes, etc.
). Despite interest from many researchers about congestion charging, there remains little appetite for first or second-best policy instruments approximating the marginal external costs of private transport in advance of the provision of a large scale investment in a mass transit alternative. This was meant to be achieved through the implementation of a number of National Development Plans (NDP) and various strategic transport plans. The latest plan, a massive infrastructural investment program entitled Transport 21
] outlined an investment of almost €35 billion ($46 billion) in transport infrastructure nationally, with about 50% going to public transportation. However, the delivery of these plans have been characterised by administrative, regulatory and financing holdups. The latter of which is likely to be the primary constraint as the finances of the Irish government worsen [17
]. In the interim, as previously noted, the car has gained an increased share of the peak time travel market. A key concern in the environmental sphere has been to maintain or even reverse this trend. This latter point is especially important given that, as of 2005, Ireland was emitting 25% more CO2
than in 1990 levels, 12 percentage points more than it is permitted under is Kyoto commitments [18
] and with a requirement to reduce greenhouse gas emissions by 20% over 2005 levels by 2020 under its “20-20-20” obligations [19
]. A number of strategies have been developed by the government to better integrate transportation and land use polices, but the diffuse nature of decision making in Dublin has hindered integrated land use planning; the City and County of Dublin, with a population of 1.2 million people is divided into four jurisdictions, each with their own planning powers.
In the international context, the interaction between land use and transportation is an extremely well explored topic [20
]. As already noted, the continued disconnect between land use and transportation planning in Dublin has also spurned considerable interest amongst researchers in Ireland. In qualitative analyses, Williams and Shiels [21
] characterise the development patterns in the GDA as laissez faire
and Williams et al.
], defined these patterns as unsustainable. In this context, it perhaps the right time to offer a quantitative insight into what these policy and economic processes delivered in terms of land use and transportation patterns and whether they offer signs of being sustainable in the longer run. It also allows the next generation of policymakers insights into what happened in Dublin over the period of the recent economic boom and how to plan accordingly.
Map of Dublin City and County and the Greater Dublin Area.
Map of Dublin City and County and the Greater Dublin Area.
Mode choice, of course, is determined by many factors. In Dublin recent analysis by Commins and Nolan [4
] explores the major influences of modal choice in the GDA using the 2006 Census of Population data. Using a conditional logit structure, the authors find the importance of individual demographic and socioeconomic characteristics on modal choice for commuters travelling to work. For instance, older people are less likely to walk, cycle or take public transit. Females are significantly more likely to travel to work by bus or train. Higher levels of income and social class, as well as the presence of children in a household, reduces the probability of using public transit, a finding similar to McDonnell et al.
]. Mode choice is also influenced by local and regional transportation characteristics. Unsurprisingly, the authors find that city centre residents and those with rail coverage are more likely to walk, cycle or use public transit while those households with higher car ownership are less likely to use these modes. While the authors conduct a detailed analysis of the determinants of mode choice, their focus does not extend to the age of the housing stock and associated development patterns and how this relates to modal choice. Our analysis is also confined to the four counties that make up Dublin City and County (Dublin City, Dun Laoghaire-Rathdown, Fingal and Dublin South) rather than the seven counties that make up the GDA (see Figure 1
Over the last decade and a half, the Irish government and local Dublin policymakers faced almost unprecedented economic growth. As shown in this paper, the latter part of the boom was characterised a rapid and unprecedented increase in the housing stock. At the same time, planners committed themselves to ensuring sustainable patterns of development and transportation through a number of very ambitious strategies, either through the provision of new public transportation infrastructure or through incentives to improve the sustainability of land use patterns.
Cross tabulation between housing stock and location characteristics.
Cross tabulation between housing stock and location characteristics.
|Year Built ||Before 1919||1919–1940||1941–1960||1961–1970||1971–1980||1981–1990||1991–1995||1996–2000||2001–2006|
|No. of Bus Stops||N||%||N||%||N||%||N||%||N||%||N||%||N||%||N||%||N||%|
|Density of Housing Units|
|Less than 1000 per km2||2140||5||1361||4||1674||3||3475||7||9145||10||7018||11||4680||12||7001||14||23,094||30|
|1001–3000 per km2||5064||13||5830||17||11,812||20||12,139||24||29,761||32||25,233||40||11,783||30||10,701||22||17,265||22|
|3001–6000 per km2||11,908||30||13,263||39||32,459||55||27,284||55||48,216||51||24,518||39||16,295||41||24,797||51||26,932||35|
|6001–9000 per km2||11,552||29||10,191||30||10,850||18||5928||12||6397||7||4630||7||3947||10||3963||8||6151||8|
|9001–12,000 per km2||7524||19||2397||7||2059||3||855||2||632||1||1079||2||1605||4||1267||3||2342||3|
|12,001+ per km2||1609||4||735||2||478||1||199||0||261||0||407||1||996||3||1373||3||1044||1|
|Number of Cars per Household|
|Three or more||3741||10||3424||10||6587||11||7621||15||18,021||19||8587||14||3870||10||4162||9||4334||6|
|Year built ||Before 1919||1919–1940||1941–1960||1961–1970||1971–1980||1981–1990||1991–1995||1996–2000||2001–2006|
|Gender||N||% ||N||% ||N||% ||N||% ||N||% ||N||% ||N||% ||N||% ||N||% |
|No. of People per Household|
However, as shown, the attempt to better integrate transportation and land use planning has been hindered by the diffuse nature of policymaking in the Dublin Area. Local authorities, incentivized by the potential for development-related revenues, engaged in widespread rezonings of previously agricultural land for low density developments, largely unregulated by the central government. Accordingly, it is very possible that a unique opportunity to reshape development patterns in Dublin has been lost. As this research shows, approximately a sixth of the total housing stock in the City and County of Dublin were built in the five years up to 2006 and that fully a quarter of the housing stock is less than 10 years old. This suggests that policymakers had a tremendous contemporaneous opportunity to influence transport, land use and development patterns in a way that would likely have brought significant changes. The strategies outlined by the central government were aimed at better integrating these strands of policymaking.
Yet, the results of this research show individuals living in housing built during the most recent period were less likely to use alternative forms of transport than those living in the pre-existing housing stock. Further, the results also indicate that most of the recent housing stock was built in low density areas, as a result the provision of such services, such as public transportation, will likely be more difficult in the future. Commuters living in the newest housing stock, who are also likely suffering the effects of negative equity as a result of the housing collapse and, as a result are less mobile, are also the ones with the least sustainable transportation patterns. One of the most compelling findings is in relation to where the newest housing stock was situated. Over 50% of the newest housing units were built in areas with existing population densities were low. Even more tellingly, the proportion of housing units built in the lowest density areas (less than 1000 housing units per square kilometre), increased from approximately one in seven units for those units built between 1996–2000 to almost a third built in the most recent period. These areas typically lack the services available to residents in higher density areas. Government provided operations such as public transport are generally more costly and less effective, accordingly residents will more likely need the use of a car.
This should give tremendous pause for thought on behalf of Irish policymakers, despite many strategies to encourage sustainable development and transportation patterns, the development patterns were, as one researcher called it, laissez-faire
. In fact, the development patterns in the most recent period of construction were moving in the opposite direction of stated land use goals. The diffuse nature of policymaking in the Dublin area has often been cited as the main administrative barrier to integrated planning. Given the recent vintage of much of the housing, policymakers should, at the very least, look towards the mistakes of the recent past, and investigate concrete ways to reverse the backwards steps of recent years. There is some evidence of this in central government [25
]. However, it will require a much larger investment in integrated land use and transportation planning than hitherto exhibited and the process should include ways to implement already existing strategies and mitigating the mistakes of recent years. As a result of the housing collapse, it is unlikely that much new housing will be built in Dublin for the foreseeable future, as such, policymakers should also explore "retrofit" policy possibilities for the existing stock of housing. On the transportation side, one such example could be the use of increased bus priority measures, already shown to be effective in parts of Dublin [23
], as a relatively low cost way to improve the efficiency of existing infrastructure and make alternative modes more attractive to current non-public transport users. As well as improving the efficiency of infrastructure, policymakers should also explore institutional reform. The public transportation market in Dublin is highly regulated with little access for new operators [13
], in light of the trends highlighted here, it is perhaps time that planners explored liberalising the bus market to see if private operators may see opportunities for feeder services that are not currently provided by the state operated bus company. If and when housing construction begins again in the Dublin region, perhaps the mistakes of the last decade may act as guidance to future policymakers both in Ireland and abroad.