|Aud Tennøy, Paal Brevik Wangsness, Jørgen Aarhaug, Fredrik Alexander Gregersen
Planning and construction of urban road capacity expansions are going on in most of the larger cities in Norway. The motivation for the projects is often to reduce congestion and/or local environmental problems, and in some cases to reduce GHG emissions by reducing congestions. However, as noted by Nolan and Lem (2002), increases in capacity on urban highways are likely to reduce the time cost of travel, thereby resulting in increased traffic volumes. In this project we examine in detail the short-term and long-term mechanisms resulting from an ongoing road-capacity expansion. Applying a case-study approach, we ask: What are the effects on road traffic volumes and GHG emissions of urban road-capacity expansions? Several sources of data have been applied, among these, register data on housing, population density and commuting patterns, as well as registration of traffic volumes and traffic flow on defined road stretches. The project also applies qualitative interviews and document studies of county plans, municipal plans and zoning plans.