Almost all studies of sleepy driving are carried out in driving simulators and with monotonous road conditions (no interaction with other cars). The present study investigated indicators of sleepy driving in a more challenging scenario after a night awake. 17 participants drove a high fidelity moving base driving simulator experiment while sleepiness was monitored physiologically and behaviourally. Short periods of situations of free driving (no other vehicles) alternated with short periods of following another vehicle (car following) with and without the possibility to overtake. The result showed that a night of prior sleep loss increased sleepiness levels at the wheel (eye closure duration and lateral variability) compared to after a night of normal sleep. Blink duration while overtaking was significantly lower compared to the other situations, it was at the same level as after night sleep. Speed when passing a stopped school bus was not significantly affected by sleepiness. However the warning caused a more rapid reduction of speed. In conclusion, a moderately challenging driving contest did not affect sleepiness indicators, but a very challenging one did so (overtaking). This suggests that it is important to monitor the driving situation in field operational tests of sleepy driving.

One critical situation when a driver needs to have a high degree of awareness, to avoid critical situations or crashes, is when passing a school bus, stopped for boarding or de-boarding of children. With the help of an experiment in VTI’s moving base driving simulator, a scenario, using in-vehicle information before the bus was reached, was tested. The aim was to enhance drivers’ perception, in order to reduce the speed of vehicles passing by the stopped bus. Both alert and sleep deprived drivers were tested. The results showed a significant speed reduction thanks to the information given beforehand. Sleep deprivation did not seem to have an impact on speed reduction. This suggests that the warning signals are seen and followed, regardless the drivers’ state of alertness. Thus, it seems likely that this type of information may be useful as an Intelligent Transport System (ITS), to provide driver support about upcoming hazards. One step towards further research in this direction is performed within the EU project SAFEWAY2SCHOOL, the main objectives of which are presented at the end of this chapter.

In this chapter, the application of macro and micro traffic simulation modelling for the needs of road safety assessment and planning is dealt. The overall concept of traffic simulation modelling regarding safety is presented, together with a series of macro and micro simulation models (namely RuTSim, S-Paramics, SATURN and VISSIM) that are widely used and have been specifically applied for the needs of IN-SAFETY project. ITS and ADAS related scenarios defined within IN-SAFETY, aiming to enhance the road safety level, have been tested through specially developed applications of these models and their results indicate the influence of the use of such technologies, as well as the effectiveness of the selected models in simulating and evaluating their effects. Future enhancement in the models will provide the possibility of further using them in the context of road safety and the involvement of innovative technologies.

Syftet med föreliggande handbok är att beskriva hur trafiksimulering kan användas som en alternativ metod eller komplement till analytiska metoder för att bestämma kapacitet och framkomlighet. Liksom metodbeskrivningarna i TRV2013/64343 är beskrivningarna avsedda att kunna användas för att med hjälp av trafiksimulering uppskatta effekterna av en given utformning i samband med planering, konsekvensanalys, projektering och drift av vägtrafikanläggningar. Simulering kan användas som ett komplement till de analytiska metoderna, eller som ersättning i fall som inte täcks av dessa metoder. Härigenom minskas risken för onödiga kostnader förorsakade av såväl över- som underkapacitet.

This paper describes the implementation of a model of a driver into a computerised numerical simulation. The model is developed to capture the essential characteristics and common aspects of cognition and behaviour of a human being in control of a "vehicle" in different surface transport systems, namely trains, cars and ships. The main functions of the simulation are discussed as well as the experiments carried out in different types of driving simulators to support the estimation of the parameters utilised in the numerical simulation. The validation processes carried out in the rail and maritime domains are also discussed together with a critical review of capacities and limitations of the proposed approach.

In Sweden, rural roads with separated oncoming lanes are becomingincreasingly important due to their superior safety properties.The level-of-service of such roads may however be reducedsince traffic is restricted by the barrier between the oncoming lanes.This level-of-service impact can be evaluated through traffic microsimulation.Such simulation based assessments of rural highwaysrequire simulation models capable of modeling rural road traffic.This paper presents a simulation study of different rural road designswith separated oncoming lanes using a rural road traffic simulationmodel. The presentation illustrates the use of simulationfor rural highways and the result of the study indicates that oncominglane separation is a competitive alternative despite slightlevel-of-service reductions compared to undivided two-lane highways.

Detta VTI notat presenterar en beräkningsmetod för beräkning av förväntad kölängdoch restidsfördröjning för enfältiga vägavsnitt utan omkörningsmöjligheter. Metodenutvecklades 2001 och presenterades i ett PM. Bakgrunden till modellutvecklingen varatt dåvarande Vägverket (nu Trafikverket) planerade att införa så kallade 1+1-vägar, detvill säga, vägar med längre delsträckor utan omkörningsmöjlighet. Den utveckladeberäkningsmetoden har sedermera visat sig värdefull även vid framkomlighetsberäkningarför 2+1-vägar med varierande andel tvåfältsavsnitt och har använts vidframtagning av hastighetsflödessamband till Trafikverkets ”Effektsamband förvägtransportsystemet”.Metoden använder avsnittslängd, trafikflöde samt medelhastighet och standardavvikelsesom indata. Metoden är uppdelad på beräkning av effekter på grund av enstakalångsamtgående fordon samt effekter vid ”normal” hastighetsfördelning. Då mätdatasaknades vid modellutvecklingen jämfördes metoden med simuleringskörningar medden mikroskopiska trafiksimuleringsmodellen AIMSUN. Resultaten visar på en relativtgod korrelation men generellt så ger den analytiska metoden cirka 1,2 procent lägrerestidsfördröjning. En stor del av skillnaden mellan modellerna vid måttliga flöden börkunna härledas till det stokastiska inslaget i simuleringen. Det bör även påpekas attvarken den analytiska modellen eller trafiksimuleringsmodellen har kalibrerats ochvaliderats mot verkliga data för denna typ av väg. Skillnaden mellan modellerna innebärsåledes inte att den analytiska modellen självklart är den som avviker från verkligheten.

Variabla hastighetsgränser är väl utbrett på Stockholms stadsnära motorvägar och en del av Stockholms Motorway Control System (MCS). Målet med dagens system är att minska risken för olyckor och följdolyckor vid låga hastigheter, trafikstockningar m.m. Detta görs genom att mäta medelhastigheten med hjälp av fasta detektorer och uppdatera hastigheten som visas på variabla meddelandeskyltar utifrån rådande trafiktillstånd. I och med att efterfrågan på resor i Stockholm under rusningstid överstiger den tillgängliga kapaciteten i vägnätet är behovet av ett effektivt trafiksystem stort. Variabla hastighetsgränser kan bidra till ökad framkomlighet, men då dagens system har som målsättning att öka säkerheten är effekter som leder till ökad framkomlighet begränsade. Dessutom finns det i dagens system ett stort beroende av fungerande detektorer som mäter trafiktillståndet så korrekt som möjligt för att valet av hastighet ska kunna bestämmas på ett effektivt sätt.

Syftet med den här rapporten är att undersöka alternativa styralgoritmer för att bestämma variabla hastighetsgränser på Stockholms motorvägsnät. Målet är att öka framkomligheten jämfört med dagens system. Två olika sträckor med olika komplexitet, trafiksituation och problematik studeras. Valet av studerade styralgoritmer för de olika sträckorna väljs för att på bästa sätt motverka den problematiken som uppstår på de specifika sträckorna. Därmed kan val av algoritmer komma att skilja sig åt beroende på sträcka. I projektet utvärderas också om estimering av trafiktillståndet kan användas för att förbättra informationsflödet till algoritmerna då detektorer inte fungerar som de ska eller helt saknas, vilket i sin tur kan leda till förbättrad anpassning av de variabla hastighetsgränserna. Detta görs av för en av de studerade sträckorna. Styralgoritmerna utvärderas med mikroskopisk trafiksimulering och metoden utvecklad i projektet Mobile Millenium Stockholm (MMS), som bygger på en makroskopisk trafikflödesmodell och Kalman filtrering, används för estimering av trafiktillståndet.

Resultatet visar att det finns styralgoritmer med potential att öka framkomligheten. Valet av styralgoritm är dock beroende av typ av trafiksituation, vägdesignens komplexitet och trafikförhållanden på vägen. Det betyder att olika styralgoritmer kan prestera olika bra beroende på vilken vägsträcka man studerar. Vidare är estimering av trafiktillståndet användbart vid förlorad information på grund av icke-fungerande detektorer eller som komplement till detektorer för att minska mängden stationär utrustning.

Variable speed limit systems where variable message signs are used to show speed limits adjusted to the prevailing road or traffic conditions are installed on motorways in many countries. The objectives of variable speed limit system installations are often to decrease the number of accidents and to increase traffic efficiency. Currently, there is an interest in exploring the potential of cooperative intelligent transport systems including communication between vehicles and/or vehicles and the infrastructure. In this paper, we study the potential benefits of introducing infrastructure to vehicle communication, autonomous vehicle control and individualized speed limits in variable speed limit systems. We do this by proposing a cooperative variable speed limit system as an extension of an existing variable speed limit system. In the proposed system, communication between the infrastructure and the vehicles is used to transmit variable speed limits to upstream vehicles before the variable message signs become visible to the drivers. The system is evaluated by the means of microscopic traffic simulation. Traffic efficiency and environmental effects are considered in the analysis. The results of the study show benefits of the infrastructure to vehicle communication, autonomous vehicle control and individualized speed limits for variable speed limit systems in the form of lower acceleration rates and thereby harmonized traffic flow and reduced exhaust emissions.

Variable speed limit (VSL) systems are used to improve the traffic conditions by adjusting the speed limits based on the current traffic situation. Advances in vehicle technology have made it possible to use connected vehicles in VSL systems. Connected vehicles can continuously transmit information about their speed and location, which can be used to estimate the current traffic conditions at arbitrary locations. In this study, we propose a VSL system based on connected vehicles. The aim is to also allow application of VSLs for non-recurrent bottleneck mitigation at arbitrary locations, unlike today's systems which require densely placed detectors or are limited to beforehand known bottleneck locations. The proposed system is evaluated by microscopic traffic simulation. The results indicate that the VSL system manage to improve traffic efficiency in a simulated incident scenario.

Variable Speed Limit Systems (VSLS) where variable message signs show speed limits based on, for example,traffic volume or road conditions exists on motorwaysin many countries. The purpose of the VSLS is to decrease the number of accidents and to increase traffic efficiency. Cooperative systems are a type of intelligent transport system that has received increasing interest lately. The central part of a cooperative system is communication between vehicles and/or vehicles and the infrastructure. In this paper, a cooperative systems extension of a VSLS is proposed and evaluated by means of traffic simulation. By adding cooperative systems functionality to an existing VSLS there is a potential for further increase in traffic efficiency and also to reduce the environmental impacts of the traffic on the road. In the proposed cooperative VSLS, communication between the vehicles and the infrastructure is made available via a roadside unit communicating the speed limits to vehicles upstream on the road. The results of the study show that the cooperative VSLS has a potential to contribute to flow harmonization and to reduce environmental impacts.

Variable Speed Limit Systems (VSLS) where variable message signs show speed limits based on, for example,traffic volume or road conditions exists on motorwaysin many countries. The purpose of the VSLS is to decrease the number of accidents and to increase traffic efficiency. Cooperative systems are a type of intelligent transport system that has received increasing interest lately. The central part of a cooperative system is communication between vehicles and/or vehicles and the infrastructure. In this paper, a cooperative systems extension of a VSLS is proposed and evaluated by means of traffic simulation. By adding cooperative systems functionality to an existing VSLS there is a potential for further increase in traffic efficiency and also to reduce the environmental impacts of the traffic on the road. In the proposed cooperative VSLS, communication between the vehicles and the infrastructure is made available via a roadside unit communicating the speed limits to vehicles upstream on the road. The results of the study show that the cooperative VSLS has a potential to contribute to flow harmonization and to reduce environmental impacts.

Variable Speed Limit Systems (VSLS) where gantries are showing speed limits based on, for example, traffic volume or other road or traffic conditions exists on motorways in many countries. The aim of the VSLS is usually to improve traffic efficiency. Lately, cooperative intelligent transport systems allowing for communication between vehicles and/or vehicles and the infrastructure has received increasing interest. A cooperative VSLS, utilizing communication between vehicles and the infrastructure, could possibly result in further improved traffic efficiency and decreased exhaust emissions and fuel consumption. In this paper, a cooperative VSLS is evaluated by the use of a microscopic traffic simulator. The cooperative VSLS is described together with a discussion on how the modeling of the cooperative VSLS and the assumptions made regarding vehicles behavior will impact the final results of the evaluation. Results from the simulations are presented with in terms of traffic efficiency and exhaust emissions.

Variable Speed Limit Systems (VSLS) where variable message signs show speed limits based on traffic or road conditions exist on motorways in many countries. The purpose of the VSLS is to decrease the number of accidents while increasing efficiency of traffic system. Cooperative systems are a type of intelligent transport system that has received increasing interest lately. The central part of a cooperative system is communication between vehicles and/or vehicles and the infrastructure. In this paper, a cooperative systems extension of a VSLS is proposed and evaluated by means of microscopic traffic simulation. In the proposed cooperative VSLS, communication between the vehicles and the infrastructure is made available via a roadside unit communicating the speed limits to vehicles upstream on the road. Both aggregate and micro-scale emission models are used to estimate emission from vehicle states in traffic flow. The results of the study show that the cooperative VSLS has a potential to contribute to flow harmonization and to reduce environmental impacts. The emission estimates in the study are dependent on the emission models being applied.

Control algorithms used for deciding on the speed limits in variable speed limit systems are crucial for the performance of the system. Today, many of the control algorithms used are based on fixed thresholds in speed and/or flow for lowering and increasing the speed limit. The algorithms are not necessarily reflecting the conditions on the road, which might lead to low traffic efficiency. Our hypothesis is that by use of a simple and efficient control algorithm that is better in reflecting the conditions on the road, both traffic efficiency and traffic safety could be increased. In this study, four control algorithms used in variable speed limit systems, and fulfilling the above criteria, are evealuted through microscopic traffic simulation. Performance indicators related to traffic safety, traffic efficiency and environmental impacts are presented. The results show that the design of, and the objective with, the control algorithm have a great impact on the performance. Moreover, the time needed for incident detection, the duration of and the size of the speed limit reduction and the location of the congestion are of importance for the performance of the control algorithms. These results will be of importance for design and implementation of future efficient variable speed limit systems.

This paper presents the results of a microscopic traffic simulationstudy of the potential effects of an overtaking assistant fortwo-lane rural roads. The overtaking assistant is developed to supportdrivers in judging whether or not an overtaking opportunitycan be accepted based on the distance to the next oncoming vehicle.Drivers have been found to consider this to be a difficultpart of an overtaking manoeuvre. The assistant’s effects on trafficefficiency, driver comfort and road safety have been investigatedusing traffic simulation. The results indicate that this type overtakingassistant can provide safety benefits in terms of increasedtime-to-collision to the next oncoming vehicle during overtakingmanoeuvres. This safety benefit can be achieved without negativeconsequences for traffic efficiency and driver comfort. A driverassistance system that supports the distance judging part of overtakingmanoeuvres can therefore contribute to improved trafficconditions on the two-lane rural roads of the future.

Efficient interchange stations, where travelers are changing lines and/or travel modes, are essential for the functionality of the whole public transport system. By studying pedestrian movements, the level of service and effectiveness imposed by the design of the interchange station can be evaluated. We address the problem by microsimulation, where a social force model is used for the phenomenological description of pedestrian interactions. The contribution of this paper is the proposal of measures describing the density, delay, acceleration and discomfort for pedestrian flows. Simulation experiments are performed for the movements in two canonical pedestrian areas, a corridor and a corridor intersection. Clearly, each of the four measures gives a description for how pedestrians impede each other, and hence for the efficiency at the facility. There is, however, different information provided by each measure, and we conclude that they all are well-motivated for quantifying the level of service in a pedestrian flow. We also illustrate the outcome for a railway platform, with two trains arriving in parallel.

Efficient interchange stations, where travelers are changing lines and/or travel modes, are essential for the functionality of the whole public transport system. By studying pedestrian movements, the level of service and effectiveness imposed by the design of the interchange station can be evaluated.

We address the problem by microsimulation, where a social force model is used for the phenomenological description of pedestrian interactions. The contribution of this paper is the proposal of measures describing the density, delay, acceleration and discomfort for pedestrian flows.

Simulation experiments are performed for the movements in two canonical pedestrian areas, a corridor and a corridor intersection. Clearly, each of the four measures gives a description for how pedestrians impede each other, and hence for the efficiency at the facility. There is, however, different information provided by each measure, and we conclude that they all are well-motivated for quantifying the level of service in a pedestrian flow. We also illustrate the outcome for a railway platform, with two trains arriving in parallel.

Microscopic simulation of pedestrian traffic is an important and increasingly popular method to evaluate the performance of existing or proposed infrastructure. The social force model is a common model in simulations, describing the dynamics of pedestrian crowds given the goals of the simulated pedestrians encoded as their preferred velocities. The main focus of the literature has so far been how to choose the preferred velocities to produce realistic dynamic route choices for pedestrians moving through congested infrastructure. However, limited attention has been given the problem of choosing the preferred velocity to produce other behaviors, such as waiting, commonly occurring at, e.g., public transport interchange stations. We hypothesize that: (1) the inclusion of waiting pedestrians in a simulated scenario will significantly affect the level of service for passing pedestrians, and (2) the details of the waiting model affect the predicted level of service, that is, it is important to choose an appropriate model of waiting. We show that the treatment of waiting pedestrians have a significant impact on simulations of pedestrian traffic. We do this by introducing a series of extensions to the social force model to produce waiting behavior, and provide predictions of the model extensions that highlight their differences. We also present a sensitivity analysis and provide sufficient criteria for stability. (C) 2014 Elsevier B.V. All rights reserved.

The global aim of the ecoDriver project is to increase the fuel efficiency by 20% by optimising the driver-powertrain-environment feedback loop and delivering effective advice to drivers. In the course of the project, field experiments will take place with a wide range of vehicles — e.g. cars, light trucks and vans, medium and heavy trucks and buses — covering both individual and collective transport. The last step of the project (Sub Project 5; SP5) is to scale up the results from these tests and analyse costs and benefits for a number of futurescenarios.

The aim of SP5 is to predict the impact of the ecoDriver systems and solutions in the future, drawing on all the evaluations carried out in the project. With the results of SP5 it will be possible to make estimates about the costs and benefits of the suggested green driving support systems on a global (EU-27) level, both for society as a whole and for sub-groups like manufacturers and consumers. SP5 will construct a set of possible scenarios for the future depending on various road maps envisioned today. The predictions for future years will be made based on available data from within and outside of the project, and on advanced microscopic traffic modelling. SP5 takes the following steps to meet the objectives:

• Collect data needed for scaling up and developing scenarios
• Create a range of scenarios
• Assess the network implications of green driving support systems for future networks
• Predict the global impacts for a range of systems and scenarios
• Carry out a cost benefit analysis for a range of systems and scenarios

This deliverable describes the data needs for each step. It also contains a description of the approaches proposed for the scenario building, the microscopic traffic simulations, the scaling up and the cost-benefit analysis.

Interchange stations with their connections between modes and lines are central for a high quality public transport system. Bus access at the station needs to operate reliably and efficiently in order to prevent congestion and queues. Here, a discrete event simulation model of vehicle movements and interactions at bus terminals is developed and implemented. The model has a modular approach, where common spatial sections at terminals are represented by modules that can be combined into various terminal layouts. These modules describe the events a vehicle may go through in a particular section of the terminal, such as arriving to a bus stop or stopping at a traffic light at the exit. The model can be used in planning processes, both for new terminals and redesign of existing ones, and is able to describe the detailed movements and interactions between vehicles that occur at larger terminals. The model is tested in a numerical experiment representing Norrköping interchange station in Sweden. The experiment shows that the model is able to evaluate and compare different scenarios and can thus be a useful tool in planning processes.

A high quality railway service requires that all parts of the complete journey, from door to door, are well-functioning. This includes any transfers taking place, as well as last mile transportation to and from the railway station. Since the last mile often consists of local public transport, the access to this mode at stops and terminals and how well these are functioning are of great importance. A critical aspect is the capacity of the stop or the terminal in relation to the number of departures, where a higher capacity generally means an increase in size. At the same time it is desirable to limit the use of valuable land and keeping the facility as small as possible. The trade-off between capacity and size needs to be evaluated when designing stops and terminals. In this study we have developed a discrete event simulation model of a combined bus and tram stop, which is a part of a larger multi-modal station. The objective of the study is to evaluate the modelling approach for the situation at hand. Of special interest are the complexities due to the different driving patterns of buses and trams. The developed model is capable of evaluating design alternatives and is applied in a case study of a stop at Norrköping railway station in southern Sweden. The model was found to realistically capture the various events occurring at such a stop and the case study further showed that the model is a useful tool in design evaluation.

Road safety is a major concern in all countries, and large effortsare constantly dedicated to create safer traffic environments. Todayincreasing attention is turned toward active safety improvingcountermeasures that improve road safety by reducing accidentrisks. Such active countermeasures include advanced driver assistancesystems (ADAS). To ensure that these new applicationsresult in real safety improvements, a priori estimations of safetyeffects are needed. This paper considers estimation of the safetyeffects of ADAS through traffic simulation. Requirements imposedon a traffic simulation model to be used for ADAS evaluation arepresented, and a car-following model to be used in simulations thatinclude ADAS-equipped vehicles is proposed. ADAS have an impacton traffic through the functionalities of ADAS and throughchanges in driver behavior for ADAS-equipped vehicles. Driverbehavior for ADAS-equipped vehicles has usually not been consideredin previous simulation studies, including those for ADASequippedvehicles. Simulation runs of rural road traffic that usedthe proposed car-following model did, however, indicate that behavioralchanges caused by the ADAS were important factors forthe safety impact. Modeling of the behavior of drivers in ADASequippedvehicles is therefore essential for reliable conclusions onthe road safety effects of ADAS.

Microscopic traffic simulation is often used as an alternative or complementary tool to analytical methods and procedures for level-of-service analyses of road traffic facilities. The increased usage of traffic simulation for level-of-service analysis has raised a need for guidelines on how to apply and use traffic simulation models. Many countries have developed or are currently developing traffic simulation guidelines. This is also the case in Sweden, were the new Swedish highway capacity manual will include a chapter on traffic simulation. This paper presents a survey of the current traffic simulation guidelines in USA, Germany, UK, Denmark and Sweden. The guidelines have been analysed with respect to the aspects covered: when to apply simulation; the workflow of a simulation study; data collection needs; calibration and validation; experimental design; statistical analysis; and calculation of level-of-service measures. The guidelines analysed are focused on different aspects and none of them covers all of the topics listed above. Some of the guidelines are connected to specific simulation software packages and some are written in a more general manner. Most of the aspects covered are general and applicable in any country. The main reason for developing country specific guidelines is often a need for guidelines in the local language. Experimental design and statistical analysis are not treated extensively in the guidelines; neither do the guidelines discuss how to deal with calibration based on limited real world measurements. Calculation of level-of-service measures are quite extensively treated in some of the guidelines and to a little extent in others. All of the guidelines contain important contributions for the simulation chapter of the new Swedish highway capacity manual

This paper presents a modified version of the Intelligent Driver Model (IDM) [M. Treiber, A. Hennecke, and D. Helbing, Phys. Rev. E. 62, 2 (2000)]. The IDM is a car-following model. A car-following model controls the accelerations of individual vehicles in a microscopic traffic simulation model. The original IDM has been observed to result in negative vehicle accelerations in situations where the distance to the preceding vehicle is much larger than the estimated desired safety distance. In this paper, we propose a modified function for the interaction with preceding vehicles which do not include this model property. A comparison of the results of simulations with the original and the modified IDM shows that the modified IDM results in higher average speed for a specific flow, a less steep speed-flow relationship and higher capacity. The speed-flow relationships of simulations with the modified IDM are also shown to better match the speed-flow relationships in real traffic on Swedish freeways. The differences between the results for the original and the modified IDM increase if the models are extended to include drivers' anticipation of the downstream traffic condition.

A unified model of driver behaviour and driver interaction with innovative technologies was developed in the European project ITERATE. The model aims to be applicable for all surface transport modes. As a basis of the model development it was assumed that underlying factors influencing human behaviour such as age, gender, culture etc. are constant between transport modes. The model can be of great use when designing innovative technologies since it will allow for assessment and tuning of the systems in a safe and controllable environment without use in real traffic. This paper presents the results of a set of driving simulator experiments carried out to support the model development process. The experiments are unique  in the sense that common scenarios were run on two identical portable driving simulator platforms circulated among project partners across five countries as well  as full scale train and car driving simulators. This allowed a large number of subjects to take part in the experiment. An important finding from the experiments was that country/culture was found to be a significant factor for almost all performance indicators in both car and train experiments. Furthermore, it seems like small scale simulators provide comparable results as more advanced simulators.

This paper presents a micro-simulation model that takes flared design of rural intersections into consideration. The intersection model is designed with input parameters that describe the geometric conditions of the flare. The behavior model includes both a traditional gap-acceptance sub-model and a passage model for modelling of vehicles’ possibility to pass other vehicles using the flare. The intersection model developed has been implemented in the traffic micro simulation model RuTSim. The gap-acceptance part of the model has been calibrated using data for stop and yield 3-way intersections. The validation was performed by using video recordings to calculate delay for the yield regulated intersection and time in queue and service time for the stop regulated intersection. The results from the validation simulations correspond well with the empirical validation data. The effect of the flare on delay has been studied by using 3 different intersection lay-outs and different levels of minor and major flow. The result shows that the delay is decreasing with increasing intersection radius.

Models based on micro-simulation of traffic flows have proven to be useful tools in the study of various traffic systems. Today, there is a wealth of traffic microsimulation models developed for freeway and urban street networks. The road mileage is however in many countries dominated by rural highways. Hence, there is a need for rural road traffic simulation models capable of assessing the performance of such road environments. This thesis introduces a versatile traffic micro-simulation model for the rural roads of today and of the future. The developed model system considers all common types of rural roads including effects of intersections and roundabouts on the main road traffic. The model is calibrated and validated through a simulation study comparing a two-lane highway to rural road designs with separated oncoming traffic lanes. A good general agreement between the simulation results and the field data is established.

The interest in road safety and the environmental impact of traffic is growing. Recent research has indicated that traffic simulation can be of use in these areas as well as in traditional capacity and level-of-service studies. In the road safety area more attention is turning towards active safety improving countermeasures designed to improve road safety by reducing the number of driver errors and the accident risks. One important example is Advanced Driver Assistance Systems (ADAS). The potential to use traffic simulation to evaluate the road safety effects of ADAS is investigated in the last part of this thesis. A car-following model for simulation of traffic including ADAS-equipped vehicles is proposed and the developed simulation framework is used to study important properties of a traffic simulation model to be used for safety evaluation of ADAS. Driver behavior for ADAS-equipped vehicles has usually not been considered in simulation studies including ADAS-equipped vehicles. The work in this thesis does however indicate that modeling of the behavior of drivers in ADAS-equipped vehicles is essential for reliable conclusions on the road safety effects of ADAS.

The interest in in-vehicle Advanced Driver Assistance Systems(ADAS) is increasing. New systems such as Adaptive Cruise Controlsand Collision Avoidance Systems are currently introduced ata rapid pace. ADAS can both substitute and complement traditionalinfrastructure based safety improving countermeasures. Toexploit the full potential of these systems, it is necessary to estimatethe systems future impact already at early developmentstages. This paper presents a traffic simulation framework foranalysis of the aggregation of individual driver/vehicle behaviourdue to ADAS to effects on the traffic system. Application of thesimulation framework is exemplified by a study of centre line rumblestrips on rural roads. The effects of physical milled rumblestrips are compared to the effects of “virtual” in-vehicle rumblestrips for both alert and sleep deprived drivers. The use of trafficsimulation made it possible to study the combined impact ofchanges in drivers’ free driving speed, reaction time and overtakingbehaviour. Indications that the different rumble strips have animpact on average journey speeds were found amongst the simulationresults. Changes in safety indicators that can be related tochanges in overtaking behaviour were also observed.

There is a need to estimate impacts of proposed driver assistance systems already at early stages of the system development process. Estimations of the impacts of new technologies have to be based on laboratory studies and modelling. This paper presents a traffic simulation based framework for estimation of the traffic system wide impacts of driver assistance systems. The framework includes a two-step methodology. In the first step of the analysis, the considered driver assistance system’s impact on driver behaviour is observed. The second step of the analysis consist of traffic simulation modelling taking into account the system functionality as well as the observed driver behaviour of the considered driver assistance system. Driver behaviour studies for use of the data for traffic simulation modelling is discussed and traffic simulation modelling of different types of driver assistance systems is exemplified by modelling of an overtaking assistant, of in-vehicle virtual rumble strips and of adaptive cruise control.

New in-vehicle driver assistance systems are currently introduced at a rapid pace. To exploit the fullpotential of these systems, it is necessary to estimate the systems future impact already at early stages of thesystem development process. This paper gives an introduction to the use of microscopic traffic simulation foranalysis and evaluation of the impacts of driver assistance systems. Application of traffic simulation foranalysis of driver assistance systems is exemplified by studies of an overtaking assistant and of adaptivecruise control.

Microscopic traffic simulation has proven to be a useful tool for analysis of varioustraffic systems. This thesis consider microscopic traffic simulation of rural roads andthe use of traffic simulation for evaluation of driver assistance systems.

A traffic simulation modelling framework for rural roads, the Rural Traffic Simulator(RuTSim), is developed. RuTSim is designed for simulation of traffic on singlecarriageway two-lane rural roads and on rural roads with separated oncoming trafficlanes. The simulated traffic may be interrupted by vehicles entering and leaving themodelled road at intersections or roundabouts.

The RuTSim model is applied for analysis of rural road design alternatives.Quality-of-service effects of three alternatives for oncoming lane separation of anexisting Swedish two-lane road are analysed. In another model application, RuTSimis used to simulate traffic on a Dutch two-lane rural road. This application illustratesthat the high level of model detail of traffic micro-simulation may call for use of differentmodelling assumptions regarding driver behaviour for different applications,e. g. for simulation of traffic in different cultural regions.

The use of traffic simulation for studies of driver assistance systems facilitateimpact analyses already at early stages of the system development. New and additionalrequirements are however then placed on the traffic simulation model. It isnecessary to model both the system functionality of the considered driver assistancesystem and the driver behaviour in system equipped vehicles. Such requirements canbe analysed using RuTSim.

In this thesis, requirements on a traffic simulation model to be used for analysisof road safety effects of driver assistance systems are formulated and investigatedusing RuTSim. RuTSim is also applied for analyses of centre line rumble stripson two-lane roads, of an overtaking assistant and of adaptive cruise control. Thesestudies establish that the assumptions made regarding driver behaviour are crucialfor traffic simulation based analyses of driver assistance systems.