Joel P. Franklin

Urban ecosystems and sustainable urban development-analysing and assessing interacting systems in the Stockholm region

In order to build competence for sustainability analysis and assessment of urban systems, it is seen as essential to build on models representing urban form, landuse and transportation, urban metabolism, as well as ecological processes. This type of analysis of interacting sub-systems requires an advanced model integration platform, yet open for learning and for further development. Moreover, since the aim is to increase urban experience with ecosystem management in the wide sense, the platform needs to be open and easily available, with high visualisation capacity. For this purpose, the LEAM model was applied to the Stockholm Region and two potential future scenarios were developed, resulting from alternative policies. The scenarios differed widely and the dense urban development of Scenario Compact could be visualised, destroying much of the Greenstructure of Stockholm, while Scenario Urban Nature steered the development more to outer suburbs and some sprawl. For demonstration of the need for further development of biodiversity assessment models, a network model tied to a prioritised ecological profile was applied and altered by the scenarios. It could be shown that the Greenstructure did not support this profile very well. Thus, there is a need for dynamic models for negotiations, finding alternative solutions and interacting with other models. The LEAM Stockholm case study is planned to be further developed, to interact with more advanced transport and land use models, as well as analysing energy systems and urban water issues. This will enable integrated sustainability analysis and assessment of complex urban systems, for integration in the planning process in Stockholm as well as for comparative sustainability studies between different cities, with the goal to build more sustainable urban systems and to increase urban experiences in ecosystem management.

Travel Time Reliability for Stockholm Roadways Modeling Mean Lateness Factor

In recent years, there has been an increasing awareness that travel time reliability, apart from expected travel time, is an important component of cost–benefit analysis, especially during congested traffic conditions. A common measure of travel time reliability is standard deviation, and it has been shown that this is a theoretically sound measure under scheduling constraints, provided that the mean lateness factor is known. Hence, in applied cost–benefit analyses, one will need both the standard deviation and the mean lateness factor. These analyses would be particularly simple if the mean lateness were constant across time of day and for different routes chosen. A study was done to explore how the mean lateness varies and how its variations can be approximated. With the use of travel time measurements on individual links, it is shown how mean lateness varies considerably across time and space. It is shown that mean lateness exhibits a time-varying pattern depending on the characteristics of congestion on the link. It is also shown that the location of the link in the network is a significant determinant. The resulting model for mean lateness represents a considerable improvement over existing practice, where the mean lateness is implicitly assumed constant, yet a large portion of its variation remains unexplained. The model is useful for informing future research but is of less value for predicting the mean lateness in broad applied settings.

DISCRETE CHOICE ELASTICITIES FOR ELDERLY AND DISABLED TRAVELERS BETWEEN FIXED-ROUTE TRANSIT AND PARATRANSIT

In the current practice of mode-choice modeling, models typically focus on the more traditional choices, such as those between automobile, transit, and nonmotorized transportation. For most travelers these are, indeed, the most relevant modes. However, for some segments of the population, particularly the elderly, the choice is more limited. This study investigates the factors that affect the elderly and disabled travelers’ choice between public transit and paratransit. Data collected from the public transit service, Sacramento Regional Transit, and the paratransit service, Paratransit, Inc., in Sacramento, California, were used to develop a mode-choice model and to calculate elasticities of significant factors. Age was found to have an elastic effect, whereas the difference in fare had an inelastic effect.

Assessing Nighttime Deliveries in Stockholm, Sweden

Off-peak-hour delivery programs are a promising but challenging concept for promoting sustainable urban logistics. Stockholm, Sweden, initialized a nighttime freight deliveries program in 2014, aimed at a more efficient and environmentally friendly delivery system within the central area of the city. The policy of shifting freight deliveries from daytime to off-peak hours generates a wide range of effects that can be analyzed from several angles. This paper identifies the social costs and benefits, how these are distributed between stakeholders, and their effects on the everyday life and operations of all interested parties. According to information and data collected through in-depth interviews with private and public stakeholders, the social benefits mainly consist of increased efficiency and productivity for carriers and receivers, reduced transport costs, fuel cost savings, and reduced congestion and accidents when trucks are moved from peak to off-peak hours. Social costs may include increased noise levels and noise disturbances; additional staff requirements, equipment, and wage costs; and higher risks in handling goods deliveries at nighttime, especially in the case of unassisted deliveries. This paper concludes by discussing the lessons learned from the trial, challenges and opportunities that arose during implementation, and the implications for enhancement of off-peak-hour delivery in Stockholm and other cities.

Role of Context in Equity Effects of Congestion Pricing

The equity effects of congestion pricing have come into focus as a potential hindrance to its acceptability in implementation around the world. Both theoretical arguments and empirical evidence about how the burden of the toll should fall on demographic groups have been mixed, depending on a variety of contextual factors such as automobile access, work schedule, flexibility, and spatial distribution of activities. Yet the evidence so far for implemented congestion pricing systems has not examined explicitly the role of such contextual factors. With the congestion pricing trial in Stockholm, Sweden, as a case study, this paper uses structural equation modeling to estimate a model of the role of age, income, and gender as independent variables; contextual factors as endogenous variables; and the change in automobile trips after congestion pricing as dependent variables. The findings indicated that gender was a significant factor in terms of the total effects and that three of the four contextual variables—access to a car, possession of a long-term transit pass, and having a workplace on the same side of the cordon as home—played significant mediating roles in the indirect effects of the demographic variables on trips by automobile. Moreover, it was found that gender was significant only when the contextual factors were included in the model. This finding suggested that a significant variable could be missed when such factors were omitted.