Investigating three complex issues regarding effects of land use- and transport-systems developments on traffic volumes and GHG emissions

Through the URBANEFF project, effects on traffic volumes and GHG emissions of three particularly relevant and complex issues in urban planning have been studied: 1) polysentric workplace location, 2) relocation of freight facilities further out into the urban structure, and 3) urban road capacity expansions. Effects of polysentric workplace location was examined using data from the Oslo/Akershus area. We found a strong tendency of higher shares of car commuting among and longer commuting distances for employees at suburban workplaces, also among those working close to suburban transit nodes. We found that rationales for travel mode choices, such as time-saving, flexibility, convenience and stress avoidance, encourage commuting by transit to central workplaces and by car to peripheral workplaces. The results raise doubt about the appropriateness of polycentric intra-metropolitan workplace development as a strategy for sustainable mobility. We investigated whether relocating freight facilities away from central areas, to using the freed-up land for more area-intensive activities (dwellings and work-places) that would otherwise have been located more peripherally, contributes to reducing total transport-related CO2 emissions. Such development is often part of land use strategies aimed at reducing traffic growth and CO2 emissions from transport in Norwegian urban regions, and elsewhere. Whether this is an effective strategy has, however, not been much investigated. Main findings are that relocating warehouses away from central urban areas, to give room for dwellings and work-places, results in reduced total transport-related CO2 emissions. The effects are stronger the more peripherally dwellings and work-places are located in scenario one, and the more centrally they are located in scenario two. If freight warehouses are relocated in ways causing detours, effects are somewhat reduced. Effects of urban road capacity expansion were examined through case study analysis in Ålesund and Oslo. Attention was paid to the indirect and long-term land-use effects and on land-use planning and policies. In both empirical cases we found traffic-inducing land-use development in the period after the road capacity expansions. Differences in planning policy and practices affected how traffic-inducing the land-use development was. The traffic growth was stronger in the affected road corridors than expected, and as compared with traffic growth in Norway. No or only short-term congestion relief was found. It was concluded that the expansions were necessary conditions for the land-use sprawl, and consequently, contributing causes for the traffic growth. Ex-ante analyses seem not to have included the land-use effects, and this is understood as part of the explanation for the discrepancies between ex-ante expectations and actual development. In both cases, municipal and regional authorities currently attempt to steer land use development in directions contributing to stop traffic growth, in accordance with national policies. Meanwhile, road authorities plan for new capacity expansions in the investigated corridors. Land use effects of the capacity expansions seem, again, not to be included in the assessments. Finally, we evaluated the regional land use and transport plan for Oslo and Akershus was against existing literature and knowledge acquired from the abovementioned research. It was concluded that the regional plan includes elements that strongly reduce the goal achievement potential: locating specialized workplaces to the outskirts of the region; allowing a relatively high proportion of new dwellings to be built in car-dependent areas, and including two major road capacity expansion projects.

Areal- og transportplanlegging og -utvikling er til dels svært politisert, og det er stort behov for solid, empirisk forskningsbasert kunnskap på dette feltet. Dette har vært svært tydelig i prosjektperioden, der særlig diskusjonene om økt veikapasitet har vært mange og tunge. Forskerne i prosjektet, og kunnskapen vi besitter og produserer, har vært og er svært etterspurte. Dette har vi særlig opplevd gjennom de mange forespørslene om våre bidrag som foredragsholdere og i media. Vi mener at vi har bidratt til en vesentlig kunnskapsheving blant fagfolk, men ikke minst blant politikere, når det gjelder effekter av arealutvikling og av økt veikapasitet. Vi mener at vi også har bidratt til en mer kunnskapsbasert offentlig diskurs om disse temaene. Gjennom forskningen i prosjektet har vi bygget sterkere og tyngre kompetanse, som vi, forskningsgruppene, våre institusjoner og samfunnet vil kunne ha stor nytte av fremover.

Despite clear objectives to reduce greenhouse gas (GHG) emissions from road transport, relatively widespread agreements on how land use and transport systems ought to be developed to achieve this, and public control of the most important means, the built environment is continuously being developed in ways contributing to increasing traffic volumes and GHG emissions. URBANEFF takes as point of departure that lack of empirical documentation of how some combinations of land use and transport-system developme nts affect traffic volumes is an important factor (among others) explaining the gap between goals and reality. URBANEFF will contribute to change this situation by documenting effects on traffic volumes and GHG emissions of three particularly relevant and complex issues in urban planning: 1) polycentric workplace locations, 2) relocation of warehouses (for freight transport) within the urban region, and 3) urban road capacity expansions. By this, URBANEFF aims at contributing to a two stage process of soc ial transformation spurring changes towards more climate-friendly travel behaviour and transport patterns: to enable planners and decision-makers to transform the ways they steer developments of the built environment, and by that allowing, encouraging and even forcing inhabitants and businesses to transform their transport patterns towards shorter travel distances and less use of private cars. An interdisciplinary research team from three strong research milieus within this field will cooperate in the pro ject. They will be supported by international experts, and by experienced practitioners participating in workshops, contributing to improve the research and the results. The research will be organised as case studies, involving various quantitative and qu alitative methods. The multiple mechanisms involved when changes of the built environment affect travel behaviour, traffic volumes and GHG emissions will be empirically investigated separately and in combination.