Suchergebnisse

Der argumenteres ofte for, at nye vejinvesteringer ikke afhjælper biltrængslen i det lange løb, og derfor ikke kan betale sig, fordi der efter nogle år igen er samme mangel på fremkommelighed. Omvendt viser beslutningsgrundlaget for mange vejinvesteringer, at vejudvidelser giver store tidsgevinster, hvilket ofte er den primære såvel politiske som samfundsøkonomiske begrundelse for projekterne. Artiklen diskuterer ud fra klassiske udbuds-efterspørgselskurver om beslutningsgrundlaget for danske vejprojekter er tilstrækkeligt, herunder om vejudvidelser er et middel til at reducere trængsel i det lange løb, samt om dette middel kvantificeres på en retvisende måde. Det vises på den ene side, at projekter godt kan betaler sig, selvom der efter nogle år er samme mangel på fremkommelighed, idet situationen uden projektet ellers ville have være værre. Men det vises også, at der er en række problemer med den måde tidsbesparelser beregnes i trafikmodeller og efterfølgende opgøres i samfundsøkonomiske analyser. Nogle af problemer øger usikkerheden i beregningerne, mens andre systematisk overvurderer tidsbenefittene af projekterne.

The Øresund Traffic Forecast Model was designed to forecast impacts of the fixed link crossing Øresund. The link connects the metropolitan area of Copenhagen with Malmö – the third largest city in Sweden. The link provides a direct rail and car connection between the two city-centres, previously only served by fast passenger boats. The latter was not connected to the rail network of Copenhagen, and parking facilities in Copenhagen near the boat was few and expensive. On the other hand several other ferry-lines connected other parts of the Copenhagen Region with the southern Sweden. Accordingly, the fixed link improved the connection between the two regions significantly – but to a varying extent for different parts of the region. The fixed link also improved the infrastructure for longer trips between the Scandinavian Peninsula and the European Continent. However, in this respect the link compete with quite a number of ferry links. From a modelling point of view, the task was difficult since the choice set included many overlapping routes and (sub-) mode-choices. For some trips, the link constitutes a significant improvement. But the link connects two countries, where culture, language and economy (e.g. labour legislation) provide a potential barrier for travel. Economic differences may also results in additional trips, e.g. shopping trips due to different VAT- and tax-levels on different goods. To model this context, tenders were invited for a large-scale traffic model project. The resulting model was in many respects state-of-the-art: A utility-based model (nested logit) was estimated from joint RP- and SP-datasets collected specifically for the study. Several sub-models (segments) were estimated for short- and long trips, and for different trip purposes. In addition, both passenger and freight traffic were described by different (sub) models. However, in reality the model failed to describe several impacts of the fixed link (as it turned out after the link opened). Especially, the model failed to describe the competition between fast boats and the rail link, and the magnitude of the social and economic barriers for short-distance traffic. Since the model itself is described in Øresundskonsortiet (2000) its structure is only briefly described in section 2 of the present paper. Accordingly, the main focus is on lessons learned from the model project, starting with a short description of the forecast results versus actual traffic in section 3. Section 4 describes different modelling issues that are considered as the main problem with conventional models. Finally, section 5 sums up the conclusions and provide some guidelines for future models of projects that involve a mixture of regional and international (long-distance) traffic.

In November 2018, the Greenlandic Parliament decided to extend the runways at two cities, Nuuk and Ilulissat, making them the main airports for international air traffic and to build a third regional airport. The decision is the result of 40 years' discussion, which is outlined in the paper. The paper places the final decision in a theoretical framework of Greenland as a peripheral and very remote country for which air travel is the only way of mobility. Literature from the latest ten years shows that improvement in air travel can contribute to economic development. On the other hand, the investment in the new airports is economically risky considered the small size of the economy. The paper therefore uses cost benefit analyses (CBA) to assess if the decision is cost-effective even without the induced and wider economic effects of the new airports, which are difficult to forecast. Based on several CBA developed over the years, the decision on the airport package seems to be cost-effective in case some of the induced effects are taken into account. For the capital Nuuk, the decision is clearly cost-effective without including induced effects. For Ilulissat, the effect depends on to what extent an airline is willing to follow up and establish a new direct connection from Europe or the American east coast. Therefore, airport authorities are also recommended to 'sell' the new airports to airlines. During the 40-year long process of discussion, the authors' institute was 15 years ago asked to develop an optimization model for air traffic in Greenland. This model (the TGB model) is described in the paper and it is concluded that it would be possible to improve the network and save annual subsidies to the internal service traffic (PSO). Unfortunately, the model was never implemented. The authors recommend to update and improve the model that is currently outdated and to use it to optimize the network when the new airports are finished.

Economic growth and globalisation create traffic growth, leading to congestion, which again increases travel times and costs. Road pricing is an instrument that may efficiently reduce the negative impacts. This volume is a collection of research papers on the use of road pricing. The focus is on passenger transport, and the papers cover a wide range of approaches, including theoretical modelling and empirical studies of road pricing experience from different cities.

In pursuing fear-reduction strategies in public transport, the total experience of accessing rail stations should be taken into account. This article correlates passengers' fear of crime at train stations with neighborhood types and income data within the pedestrian catchment area. The research is based on urban form and income around 84 S-train stations in the Copenhagen metropolitan area and nine years of passenger surveys on fear of crime at these stations. The study reveals a significant positive correlation between low income and fear of crime; the lower the income in an urban area, the more unsafe passengers feel at the station. However, when controlling for the relationship between income, safety and neighborhood type, stations in neighborhoods with urban form associated with low incomes have the lowest ratings of safety. The research indicates that train passengers' sense of security is connected to neighborhood type and the city's planning characteristics. This is an important finding for urban designers and planners working on the integration of public transport and station design in urban areas.

This paper presents the estimation of a discrete freight transport chain choice model for Europe, which was developed for the European Union as part of the Transtools 3 project. The model describes nine different multi- and single mode chain alternatives of which three can be either container or non-containerised, and it segments freight into dry bulk, liquid bulk, containers and general cargo. The model was estimated on the basis of disaggregate data at the shipment level (Swedish CFS and French ECHO data). Several transport costs specifications and nesting structures were tested and elasticities compared with reference literature. It was found that freight models are characterised by heterogeneity, non-linearity in transport costs and hence Value of Times and non-constant rates of substitution. Not taking these elements into account will have consequences for the evaluation of transport policies using the freight transport model.