Traffic simulation is a growing research field which enables study and evaluation of the dynamics of a traffic system with the help of today’s various traffic simulation models. Rural roads with separated oncoming lanes and alternating lanes for overtaking, so-called 2+1 roads, are becoming increasingly common in Sweden due to its positive safety effects. In Sweden, there is today only one traffic simulation model developed for simulation of these road types, RuTSim (Rural Traffic Simulator). RuTSim is a research tool which makes it difficult to apply for others than the developers. This study therefore investigated whether the more accessible open-source code traffic simulation model SUMO (Simulation of Urban MObility) developed for urban and motorway traffic can be modified for modeling of traffic operations on 2+1 roads. Simulations of a virtual 2+1 road section were examined qualitatively and quantitatively using various comparison metrics aimed at capturing the characteristic traffic operations and human driver behavior on 2+1 roads. The results were further compared with an identical road section simulated in RuTSim. By adjusting parameters in the SUMO model and using its source code in its original form, the results show that it is to some extent possible to reflect the traffic operations and human driver behavior on 2+1 road, while some important mechanisms cannot be fully captured. By further modifying the source code in such a way that the speed of overtaking vehicles is temporarily increased, some of these missing mechanisms are successfully captured. The conclusion is that SUMO to some extent can model 2+1 roads, but the simulation model still lacks some basic mechanisms for capturing some of the traffic operations. For future studies, it is recommended to focus on further developing the sub-models for the merging behavior at the end of the two-lane sections, which differs compared to merging at on-ramps or lane closures since merging on 2+1 roads are part of an overtaking process.

Purpose: The purpose of this degree project was to redesign Härnösand's square called Stora Torget. Method: To complete this degree project, a literature study, case study, and analysis of various documents were performed. A site visit was accomplished and four different interviews with experts, and a survey for Härnösand residents was also done. Results: The results showed that a redesign of a square means a change. This change can be an upgrade of the square both visually and functionally. Physical elements such as seating and greenery affect the experience when visiting a square. There were some differences between the residents and experts in several opinions about how a square is designed best. The design proposal was developed with the help of Autodesk Revit, and the proposal has taken into account the opinions of both the experts and the residents of Härnösand. The proposal creates opportunities for a stronger meeting place but also a more well-utilized square for both residents and visitors, by implementing physical elements such as several seats where people can meet and socialize. Conclusions: The work concludes that physical elements affect the design of the square and that the design proposal can be a basis for future changes to the square.