This report, which provides an overview of the compulsory basic training for train drivers in Sweden, highlights the occurrence of simulator-based training in education, along with the training efforts being made with regards to the future introduction of ERTMS/ETCS. The report also shows the possibilities and limitations of increased use of simulators in driver training and describes the most important governing documents for train drivers and train driver training. Furthermore, the Swedish Transport Agency curriculum for train driver licenses is presented along with the institutions engaged in basic education, training and examination of train driver’s. Also, the Swedish Transport Administration’s E-learning tool for ERTMS, the ERSA-simulator and company specific ERTMS education at SJ and Green Cargo are described. Moreover, Swedish train companies’ and educators’ current use and future needs of simulators for train driver training were examined. Examples from other domains where simulators are used in a training context are also presented.

New simulator models concerning vibration, noise and graphics have been designed and implemented in the VTI Simulator III. The objective of this study is to validate this simulator in terms of road surface realism. Twenty-four drivers participated in the study and drove the same route both in the simulator and on real roads. Three road sections ranging from very smooth to rather uneven were incorporated in the design. The comparison included the objective driving parameter speed as well as subjective parameters from questionnaires and rating scales (evenness, quietness and comfort level). A road section with five speed limit changes was of particular interest in the analyses. No statistically significant difference could be found between the simulator and the car, neither in the parameter speed (in sections with no speed limit changes) nor in the ratings evenness and quietness. Despite similar speed profiles surrounding the speed limit signs, there was a statistically significant difference between the speed in the car and in the simulator, with more rapid accelerations and decelerations in the simulator. The comfort rating was shown to be higher in the car compared to the simulator, but in both cases the general trend showed higher comfort on smoother roads. These results indicate absolute validity for the ratings evenness and quietness, and for the measure speed, and relative validity for comfort and speed surrounding speed limit signs.

Percent road center (PRC) is a performance indicator which is sensitive to driver distraction. The original definition of PRC is based on fixation data extracted from eye movement recordings, but it has also been suggested that PRC can be determined directly from the gaze data without segmenting it into saccades and fixations. The primary aim of this paper is to investigate if this is the case.

Naturalistic driving data from a small scale field operational test comprising seven vehicles was used in the evaluation. It was found that PRC time traces based on gaze data and fixation data, respectively, were highly similar (correlation coefficient=0.95, average wavelet semblance=0.84) except for an absolute amplitude difference of about 8%. This indicates that the two approaches can be used interchangeably and that the processing step of segmenting gaze data into saccades and fixations can be left out.

In addition to this finding, design issues related to the calculation of PRC are investigated. Especially, the impact of gaze cases pointing towards the intersection of the road centre area and the centre rear mirror were investigated. Results lead to conclude that gazes and fixations on the centre rear mirror should be removed from the PRC calculations, as they may negatively influence the correctness of the performance indicator.

This study investigates a new tire force estimator based on the recursive least square (RLS) method. Tire force estimation with known driving wheel torque is studied and compared to the case with torque estimation from the internal combustion engine. This is motivated by a future scenario with electric propulsion, which reasonably gives improved wheel torque estimations. Sensitivity to vehicle parameters and challenges with individual lateral tire force estimation are also investigated. The results, experimental and simulation data, show good performance and potential for tire force estimation using the RLS method.

More accurate information about the basic vehicle parameters can improve the dynamic control functions of a vehicle. Methods for online estimation of the mass, the rolling resistance, the aerodynamic drag coefficient, the yaw inertia and the longitudinal position of the centre of gravity of an electric hybrid vehicle is therefore proposed. The estimators use the standard vehicle sensor set and the estimate of the electric motor torque. No additional sensors are hence required and no assumptions are made regarding the tyre or the vehicle characteristics. Consequently, all information about the vehicle is available to the estimator.

The estimators are evaluated using both simulations and experiments. Estimations of the mass, the rolling resistance and the aerodynamic drag coefficient are based on a recursive least-squares method with multiple forgetting factors. The mass estimate converged to within 3% of the measured vehicle mass for the test cases with sufficient excitation that were evaluated. Two methods to estimate the longitudinal position of the centre of gravity and the yaw inertia are also proposed. The first method is based on the equations of motion and was found to be sensitive to the measurement and parameter errors. The second method is based on the estimated mass and seat-belt indicators.

This estimator is more robust and reduces the estimation error in comparison with that obtained by assuming static parameters. The results show that the proposed method improves the estimations of the inertial parameters. Hence, it enables online non-linear tyre force estimators and tyre-model-based tyre–road friction estimators to be used in production vehicles.

Modern vehicles are complex systems consisting of an increasing large multitude of components that operate together. While functional verification on individual components is important, it is also important to test components within a driving environment, both from a functional perspective and from a driver perspective. One proven way for testing is vehicle simulators and in this work the main goals have been to increase flexibility and scalability by introducing a distributed driving simulator platform.

As an example, consider a workflow where a developer can go from a desktop simulation to an intermediate driving simulator to a high fidelity driving simulator with Hardware-In-the-Loop systems close to a finished vehicle in an easy way. To accomplish this, a distributed simulation architecture was designed and implemented that divides a driving simulator environment into four major entities with well-defined interfaces, using HLA as the method of communication. This platform was evaluated on two aspects, flexibility/scalability and timing performance. Results show that increased flexibility and scalability was achieved when using a distributed simulation platform. It is also shown that latency was only slightly increased when using HLA.

For assessing whether a system model is a good candidate for a particular simulation scenario or choosing the best system model between multiple design alternatives it is important to be able to evaluate the suitability of the system model. In this paper we present a methodology based on finite state machine requirements verifying system behavior in a Modelica environment where the intended system model usage is within a moving base driving simulator. A use case illustrate the methodology with a Modelica powertrain system model using replaceable components and measured data from a Golf V. The achieved results show the importance of context of requirements and how users are assisted in finding system model issues.

A car model in Modelica has been developed to be used in a new setup for distributed real-time simulation where a moving base car simulator is connected with a real car in a chassis dynamometer via a 500m fiber optic communication link. The new co-simulator set-up can be used in a number of configurations where hardware in the loop can be interchanged with software in the loop. The models presented in this paper are the basic blocks chosen for modeling the system in the context of a distributed real-time simulation, estimating parameters for the powertrain model, the choice of numeric solver, and the interaction with the solver for real-time properties.

The ViP Simulator Sound Renderer (SIREN) software has been created as a means to facilitate generation and playback of audio signals in driving simulators. Siren is a modular, scalable program with a plug-in based infrastructure. The included plug-ins offer sound file playback, sound stream playback and spatialization possibilities. Required additional functionality can be added by creating custom plug-ins. Siren by default relies on the OpenAL library for spatialization and on Csound for sound stream generation. Other spatialization and generation software can be used by replacing the corresponding API modules. Siren is implemented in the new Simulator IV as well as in Simulator III at VTI and will also be implemented in Simulator II in the immediate future. Experimental implementations have been tested in the VTI Foerst simulator running solely under the Microsoft Windows operating system. Volvo Trucks has a trial version implemented in their simulator and has made some local customization. The current sound models implemented through Siren in the VTI simulators consist of real-time synthesis of sound based on measurements performed in real vehicles (car and truck) on the Volvo test track. The resulting sound has been validated through corresponding measurements performed inside the simulator cabins as well as through informal listening by experienced drivers.

The main objective of this study was to investigate how an electronic stability control (ESC) system may aid the driver in a critical sideswipe accident. Another objective was to investigate the possibility of having a realistic simulation of a sideswipe accident in a large moving base simulator. The experiment can be divided into two parts. In part one, the driver is unaware of the sudden side impact and in part two, the side impact was repeated six times.

The experiment was driven by 18 persons. With the ESC system active no driver lost control, while with the system inactive there were five drivers that lost control in part one. In part two, the ESC system showed to stabilize the vehicle faster, and the improvement in stabilization time was between 40% and 62%. It was also seen that 2% loss of control occurred with an ESC system active and 45% without.

When performing a driving simulator study, validity of the vehicle model for the intended driving task is of key importance; otherwise, the reliability of the study results might be jeopardized. In this paper a framework for real-time credibility assessment of the simulated longitudinal dynamics by a powertrain model in a moving base driving simulator is presented. The framework consists of the physical system model and a quality model which run in parallel in real time. The developed framework has been evaluated by offline simulations, as well as in real-time in a moving base driving simulator. The evaluation results showed that the developed framework can accurately capture the validity of the powertrain model in different driving conditions and provide the credibility level of the simulation results to the simulator operator in real-time.

The automotive industry is facing a major challenge to reduce environmental impacts. As a consequence, the increasing diversity of powertrain configurations put a demand on testing and evaluation procedures. One of the key tools for this purpose is simulators. In this paper a powertrain model and a procedure for parameterizing it, using chassis dynamometers and a developed pedal robot are presented. The parameterizing procedure uses the on-board diagnostics of the car and does not require any additional invasive sensors.

Thus, the developed powertrain model and parameterization procedure provide a rapid non- invasive way of modelling powertrains of test cars. The parameterizing procedure has been used to model a front wheel drive Golf V with a 1.4L multi-fuel engine and a manual gearbox. The achieved results show a good match between simulation results and test data. The powertrain model has also been tested in real-time in a driving simulator.

The automotive industry is facing a major challenge to reduce environmental impacts. As a consequence, the increasing diversity of powertrain configurations put a demand on testing and evaluation procedures. One of the key tools for this purpose is simulations.

In this paper a powertrain model and a procedure for parameterizing it, using chassis dynamometers and a developed pedal robot are presented. The parameterizing procedure uses the on-board diagnostics of the car and does not require any additional invasive sensors. Thus, the developed powertrain model and parameterization procedure provide a rapid non-invasive way of modelling powertrains of test cars. The parameterizing procedure has been used to model a front wheel drive Golf V with a 1.4L multi-fuel engine and a manual gearbox. The achieved results show a good match between simulation results and test data. The powertrain model has also been tested in real-time in a driving simulator.

To evaluate driver perception of a vehicle powertrain a moving base simulator is a well-established technique. We are connecting the moving base simulator Sim III, at the Swedish National Road and Transport Research Institute with a newly built chassis dynamometer at Vehicular Systems, Linköping University.

The purpose of the effort is to enhance fidelity of moving base simulators by letting drivers experience an actual powertrain. At the same time technicians are given a new tool for evaluating powertrain solutions in a controlled environment.

As a first step the vehicle model from the chassis dynamometer system has been implemented in Sim III. Interfacing software was developed and an optical fiber covering the physical distance of 500 m between the facilities is used to connect the systems. Further, a pedal robot has been developed that uses two linear actuators pressing the accelerator and brake pedals. The pedal robot uses feedback loops on accelerator position or brake cylinder pressure and is controlled via an UDP interface.

Results from running the complete setup showed expected functionality and we are successful in performing a driving mission based on real road topography data. Vehicle acceleration and general driving feel was perceived as realistic by the test subjects while braking still needs improvements. The pedal robot construction enables use of a large set of cars available on the market and except for mounting the brake pressure sensor the time to switch vehicle is approximately 30 minutes.

Motion parallax due to the driver’s head movement have been implemented and tested in VTI Driving Simulator III. An advanced camera-based system was used to track the head movements of the driver. The output from the tracking system was fed to the simulation software, which used low-pass filtering and a forward prediction algorithm to calculate an offset. The offset was then used by the graphics software to display the correct image to the driver.

The effects of driving with motion parallax in the simulator were also observed by an initial study. During the experiment, the subjects caught up with several slower vehicles which forced the driver to make an overtaking maneuver. Oncoming traffic forced the subject to search for a suitable gap for overtaking. The study also included a speed perception test. The results from the study showed no difference in lateral positioning when running behind a slower vehicle nor in speed perception with and without motion parallax.

The Swedish Road Administration considers permitting longer and heavier trucks on Swedish roads, provided that they do not affect traffic safety. The purpose of the study was to investigate the effect of truck length, particularly accident risk associated with overtaking. Interviewed drivers of 30 meter trucks had not experienced the problems predicted by drivers of ordinary trucks concerning narrow roundabouts and intersections, but mentioned the importance of a supportive truck company, working environment and truck equipment. A simulator study investigated car drivers overtaking trucks 30 m and 18.75 m long on a 2+1 road where two lanes merges to one. The headway time gap was 0.2 sec. (sign.) shorter after overtaking the 30 meter truck in situations where the back was in the same relative position as of the 18.75 meter truck. A field study analysed video-recorded overtakings of a 30 meter and a 24 meter timber truck on a 2+1 road and a two-lane road. No significant differences were found between headway time gaps when overtaking the two trucks, regardless of road type. The latter result should be interpreted with great caution because of unevenly distributed data collected during specific conditions. The conclusions are that longer trucks may have a small negative effect on overtaking situations, and that further field studies are required.

The purpose of this paper is to investigate if the introduction of extra-long and heavy trucks has an effect on traffic safety on Swedish roads, especially in relation to overtaking maneuvers. Traffic safety effects will be measured in terms of road user behavior concerning accelerations and time slots. First, focus group interviews with heavy truck drivers. Truck drivers that do not drive extra-long trucks believe that the introduction of extra-long trucks will create a number of traffic safety problems especially in terms of conflicts with ordinary road users. The drivers of extra-long trucks do not experience the problems that ordinary truck drivers predict. The problems they experience can be taken care of with more planning (thinking ahead). They also believe that the traffic sign on the back of the extra-long vehicle has a positive effect. The truck company, working environment and truck equipment are other important aspects mentioned by the drivers of the extra-long vehicles.

The simulator study investigates overtaking situations on a 2+1-lane highway, with extra-long trucks (30.4 m) and ordinary trucks (18.75 m). The results reveal that the distance from the rear/front of the truck to the point where only one lane exists affects car drivers’ decision to overtake, independently of truck length. If the truck is in the relatively same position, the timeslot for a safe overtaking maneuver before next one-lane section was reduced significantly for extra-long trucks compared to ordinary trucks. The conclusion is that there exist small tendencies which point in the direction of enhanced traffic safety problems with the introduction of extra-long trucks. The results should, however, be interpreted with caution as the number of data points was few and collected in specific situations and in specific conditions. It was neither considered how the introduction of longer and heavier trucks, given a constant amount of goods, reduces the number of heavy trucks on the road network.

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.

Wireless technology supporting vehicle-to-vehicle (V2V), and vehicle-to-infrastructure (V2I) communication, allow vehicles and infrastructures to exchange information, and cooperate. Cooperation among the actors in an intelligent transport system (ITS) can introduce several benefits, for instance, increase safety, comfort, efficiency.

Automation has also evolved in vehicle control and active safety functions. Combining cooperation and automation would enable more advanced functions such as automated highway merge and negotiating right-of-way in a cooperative intersection. However, the combination have influences on the structure of the overall transport systems as well as on its behaviour. In order to provide a common understanding of such systems, this paper presents an analysis of cooperative ITS (C-ITS) with regard to dimensions of cooperation. It also presents possible influence on driving behaviour and challenges in deployment and automation of C-ITS.

This paper describes the design of a video see-through augmented reality system for active safety testing. The development is explained in detail, with focus on the design considerations for the different subsystems. It is shown that it is possible to build a system using available commercial off-the-shelf components, while still maintaining the performance needed for the intended application. Accuracy and resolution requirements of the tracking systems are discussed along with measurement methods. We also examine how to use the hardware efficiently to minimize latency and a device to measure and quantify end-to-end latency has been developed.

Even though the realism of driving simulators increases constantly, there is a potential issue with how representative the test is compared to a real life scenario. An alternative to simulators is to present a mixture of real and simulated environment to the driver and perform the scenario at a test track when driving a real vehicle. This enables an efficient way of testing that inherits many of the advantages of driving simulators as well as some of the advantages of physical testing in prototype vehicles. The present paper is a compilation of previous research in augmented reality in vehicle driving situations, focusing on technical limitations of Head-Mounted-Displays.

With today’s advanced measurement equipment for measuring roads, it is possible to measure road geometry at high precision within a large span of wavelengths. Detailed information about the roads longitudinal and lateral profile, including macro texture, would in theory be sufficient for a realistic reproduction of road induced vibration and noise in a driving simulator. Especially, it would be possible to create a direct connection between the visual information of the road condition and the ride experience, which would increase the level of realism in the simulation. VTI has during three years performed an internal project called SHAKE with the aim to develop and implement models in VTI driving simulator III that use measured road data for generating realistic vibrations and audible road noise connected to the visual impression presented on the projection screen. This has indeed resulted in an more realistic driving experience, and a validation study with test persons driving both in the simulator and in the field has been undertaken. The OpenDRIVE standard is used as a framework for describing the road properties (e.g. visual, vibrations and noise). For this purpose some augumentations to the OpenDRIVE standard had to be made. This paper describes the technical implementations in the driving simulator, along with results from test drives on the implemented road sections

The Swedish Road and Transport Research Institute (VTI) has three advanced moving base driving simulators. The aim of this project was to develop and implement new models concerning vibration, noise and graphics in order to improve the realism in the simulators. Moreover, a validation study was to be conducted.

Within the frame of the project the following were achieved:

• improvement of the tyre/road vibration models,
• •improvement of the motion system by changing the rotation centre,
• •improvement of the noise module facilitating reproduction of noise from tyre/road,
• •synchronization of the impressions from graphics, noise and vibrations caused by the road surface.

The validity of the models was tested in the VTI Simulator III. Statistical testing of differences between the car and the simulator indicated absolute validity for the subjective ratings of evenness and noise level and the objective measure speed, with the exception of areas surrounding speed limit signs where only relative validity was found. Relative validity was also indicated for the variable overall comfort. The results from the different validations show that the improvements have been successful and the driver in the simulator can now see, hear and feel the sensation of any road surface irregularities exactly when the wheels hit that part of the road. However, several improvements in the simulator models can still be desired.

The sine with dwell (SWD) manoeuvre has received much attention within the context of vehicle stability testing. This manoeuvre is used in a test developed by the NHTSA, designed to certificate electronic stability control systems in light vehicles. The test is used in legislations as well as in consumer tests all over the globe. The SWD manoeuvre was designed using test vehicles on a test track and experimentally validated. The paper at hand uses optimal control theory to theoretically justify the use of the SWD manoeuvre to produce a severe lateral motion and over-steering based on steering input. It is shown that a manoeuvre similar to the SWD manoeuvre can be obtained from an optimal control problem using simple vehicle dynamics models. The optimal control method is further used to analyse the manoeuvre's robustness with respect to vehicle dimensions and tyre properties. It is shown that the manoeuvre is robust in dimensions, which theoretically motivates its application for various sizes of vehicles.

eVALUE is addressing active safety functions and their capability to perform through two courses of action: defining and quantifying the requirements of a safety function under a relevant traffic accident scenario and developing the testing and evaluation methods for the active safety functions of vehicles. WP2 aims at developing testing procedures based on the system descriptions and scenarios defined in WP1. The testing procedures will be integrated in WP3 and finally carried out and assessed in WP4. D2.2 takes the output of D2.1 and, where scenarios, safety functions and test procedures are related, defines the basis for the test procedures further developed in the next work packages. The test procedures are drafted, taking into account the future “testing protocols” and the “assessment protocols”. The document is structured according to the scheme followed from the project start, where tests are classified into “Design Reviews”,”Physical Testing” and “Laboratory Testing”. The test procedures are also classified depending on clustering different safety functions: “Longitudinal Assistance”, “Lateral Assistance” and “Stability”.

Driving simulators are a useful research tool in studies of vehicle and transport-related human machine interface. A vital part of the driving simulator is the vehicle dynamics model. In the present paper, such a model is developed. The model implements basic first order phenomena, but is yet complete in the terms of modelled parts of the vehicle. A major challenge is the trade-off between simplicity and accuracy imposed by the capabilities of the driving simulators motion platform. The modelling language Modelica was used for readability reasons. The model has been validated toward both measurements of a real car and subjectively in a driving simulator. It is shown that the model is well capable of fulfilling the imposed requirements, despite its simplicity. The model is open and available upon request.

From a traffic safety perspective it is highly motivated to define winter tires interms of their performance in icy road conditions. The present definition of winter(snow) tires, introduced in the EU in 2012, is based on packed snow performance.The present paper investigates the feasibility of an indoor winter tire classificationtest on ice. Results presented here indicates that a test procedure in an indoorhockey rink is possible, with relatively high repeatability. However, further fieldtest is required to fully establish feasibility of the procedure.

Tyre modelling is an important part of understanding and estimating the tyre-road friction. In this paper a basic steady-state tyre model for the combined-slip case is derived. The model is intended to be used in friction estimations applications, where the model complexity is of high priority. The model, described using only two parameters, is validated with measured data from various conditions and tyre types using mobile measurement equipment. The performance from the measurements suggests that only two parameters are sufficient for the combined-slip case.

The credibility of the research results of driving simulator studies is highly dependent on the realism that the simulator is capable of producing. A key component is therefore how realistic the driving is perceived by the drivers (test subjects). Overtaking is a frequently occurring traffic situation (as well as one of the highest risk manoeuvres). The aim of the present study was to enhance the perceived realism of overtaking situations in a motion-based driving simulator by introduce aerodynamic forces and moments. An earlier developed real time model of the aerodynamic forces and moments was been implemented and tested in a study with test drivers.With an appropriate scaling of the forces and torques it was shown that the perceived realism can be enhanced by the introduction of these effects.

Many traffic accidents are due to winter conditions like slippery roads and limited visibility. The road administrators put a lot of effort into snow removal and de-icing the roads, and the vehicle manufacturers have been working with functionality to support drivers in winter conditions for decades.

Many issues of driving in winter conditions originate in drivers’ behaviours such as risk taking and lack of awareness. Studying drivers’ behaviour in winter conditions in general, and the effect of various countermeasures of the vehicle, would increase the understanding of the underlying mechanisms and could possibly be used to reduce the accident risks. Motion-base driving simulators are tools frequently used for driving behaviour research. However, the validity of the results of such studies depends to a large extent on the realism of the simulation. The purpose of this project was to study winter simulation with the aim to improve the realism of simulator driving in winter conditions.

Driving in winter is in many ways different from driving in summer. The difference can to a considerable extent be explained by the tire-to-road interaction. Winter driving is typically characterized by softer motion and slower development of tire forces. In the present project two aspects of the motion have been studied, the motion feedback in the simulator and models for tire-to-snow behaviour.

Vehicle motion during winter driving is characterized by large vehicle body slip angles and the associated yaw motions. Thus, understanding the importance of yaw motion feedback is essential to simulate winter conditions. A study was designed to investigate the impact that lack of yaw motion will have on the driver, and if it alters his driving behaviour. It was found that the yaw motion alters the driving behaviour, implying that it contains vital information for a wide range of driving situations. A second study was carried out to investigate if the rotation centre, which is a consequence of the yaw and lateral motions, can be used to present valuable information about the vehicle state to the driver. Indicative results suggest that the rotation centre of the motion is valuable to the driver, but further studies are needed. The softer and slower motions of winter driving suggest that pre-positioning of the simulator’s motion platform could be performed to improve the motion envelope. A third implementation study performed in the project suggests this.  

The tyre to road contact friction is one of the most important properties when it comes to manoeuvrability of ground vehicles and information, to driver and vehicle, is of vital importance in critical situations. Different characteristics of different friction estimation methods make it hard to determine and compare performance of estimators. This article is an attempt to define and evaluate the performance of tyre to road friction estimators. The objective of the performance evaluation is to define and grade the performance of estimators based on all sorts of approaches and combinations of these. The result may be used in the context of benchmarking as well as a tool in the development process of the estimator. The test methods and metrics presented are illustrated with a comparative study of three different estimation approaches

This report is the document summarising the testing experience and knowledge gained from the physical testing activities within the eVALUE project. The document contains brief introductions to the testing scenarios as well as short summaries of conclusions. Appended to this document are the testing reports that have been compiled during the different test sessions. Physical testing at test tracks all across Europe has been the main input in the development of scenarios and test procedures. This document describes the development tests that have been performed during 2010, based on a first draft set of testing protocols. The experience from the performed tests has been used as an important input to the revision of the testing protocols, i.e. the formal documents that describe how a test should be performed and evaluated. These protocols are documented in the separate Deliverable 3.2.

The evaluation of active safety functions like Electronic Stability Control (ESC) is of increasing importance, driven by legislation, to commercial heavy vehicle producers and to society as a whole to predict the potential benefits of the systems. Direct testing in real traffic with normal drivers of those functions are most often infeasible due to cost, repeatability and safety. This paper presents an attempt to explore the possibility of using large scale moving based driving simulators to evaluate functions like ESC. This is conducted through a simulator experiment where the subject drivers have been provoked in driving scenarios to ESC interventions. The experiment indicates the possibility of using driving simulators for evaluation purposes. This implies that studies of the benefits can be performed with higher accuracy regarding repeatability and evaluation testing of active safety functions can be made more cost efficient and without jeopardizing safety of involved driver and other road-users.

To better utilize the potential of system simulation models and simulators, industrially applicable methods for Verification, Validation and Uncertainty Quantification (VV&UQ) are crucial. This paper presents an exploratory case study of VV&UQ techniques applied on models integrated in aircraft system simulators at Saab Aeronautics and in driving simulators at the Swedish National Road and Transport Research Institute (VTI). Results show that a large number of Verification and Validation (V&V) techniques are applied, some of which are promising for further development and use in simulator credibility assessment. Regarding the application of UQ, a large gap between academia and this part of industry has been identified, and simplified methods are needed. The applicability of the NASA Credibility Assessment Scale (CAS) at the studied organizations is also evaluated and it can be concluded that the CAS is considered to be a usable tool for achieving a uniform level of V&V for all models included in a simulator, although its implementation at the studied organizations requires tailoring and coordination.

In this ViP project the focus of investigation was whether drivers more readily accept either rumble strips or an in-vehicle lane departure warning system (LDW) in unintentional lane departure situations. The results show that acceptance was high for both alternatives, but while the drivers showed more satisfaction from using the LDW, they also showed more trust in the rumble strips. Twenty-four drivers drove the VTI driving simulator SIM III in car mode with simulated rumble strips in one drive and with a simulated Volvo LDW in another drive. A forced yaw motion of the vehicle induced the unintentional lane departures. The results showed no choice in favour of the LDW or the rumble strips, but a clear preference for having a function that warns for unintentional lane departure. Several participants thought it was good to have both types of warning in parallel. Although Response completion time was shorter with the rumble strips warning, there was no difference between the warning types, neither in Time to get car back in lane nor in Lane exceedence area. Thus, there were no major overall differences between the LDW and the rumble strips as measured in the present study. The conclusion is that the drivers’ acceptance, as well as performance, was high for both the rumble strips and the LDW. The positive opinion on the need for assistance systems in unintentional lane departure when drivers are directing their visual attention away from the road is thus further strengthened.

Driving simulator studies can reveal relevant and valid aspects of driving behavior, but underestimation of distance and speed can negatively affect the driver's performance, such as in performance of overtaking. One possible explanation for the underestimation of distance and speed is that two-dimensional projection of the visual scene disrupts the monocular-based illusory depth because of conflicting binocular and monocular information of depth. A possible solution might involve the strengthening of the monocular information so that the binocular information becomes less potent.

In the present study, we used an advanced high-fidelity driving simulator to investigate whether adding the visual depth information of motion parallax from head movement affects sense of presence, judgment of distance and speed, and performance measures coupled with overtaking. The simulations included two types of driving scenario in which one was urban and the other was rural. The main results show no effect of this head-movement produced motion parallax on sense of presence, head movement, time to collision, distance judgment, or speed judgment.

However, the results show an effect on lateral positioning. When initiating the overtaking maneuver there is a lateral positioning farther away from the road center as effect of the motion parallax in both types of scenario, which can be interpreted as indicating use of naturally occurring information that change behavior at overtaking. Nevertheless, only showing tendencies of effects, absent is any clear additional impact of this motion parallax in the simulated driving.

This report compiles the results from the project Theme Environmental risks. More specifically, the project concerned how different transport related environmental risks influence different road users and how their behaviour influence the environment. The project aimed at preparing for interdisciplinary research about environmental risks at VTI. The project was divided into three parts. The first subproject aimed at compiling literature about transport related environmental risks from psychological and economic perspectives, and in the second subproject a willingness to pay study was outlined where both economic and psychological principles were considered. In the third subproject, a simulator study was outlined. The focus was to study environmental effects of driving under controlled circumstances in the driving simulator. The report is divided into two parts. In part 1, the results from the literature review and the proposal for a willingness to pay study are described (subproject 1 and 2). This part is written in English. Part 2 contains a project outline for a simulator study in the form of an research project application (project 3). This part is written in Swedish.

Additional sound capabilities in visually advanced simulators may offer researchers and practitioners better resources to evaluate in-vehicle auditory signals and advanced auditory displays. In the first part of the present report, the implementation of a new audio system in the Scania truck cabin for the driving simulators II and III at the Swedish National Road and Transport Research Institute (VTI) is described.

The new audio software is based on the Open Audio Library (OpenAL) implementation for the Macintosh Operating System OS X. It communicates with the existing simulator software using the Open Sound Control (OSC) standard. The remaining program code is open, which offers the possibility of adapting the audio system to future demands and specific needs of partners within the competence centre ViP (Virtual Prototyping and Assessment by Simulation).

Another aim of the present project was to investigate the potential of urgent alarms to raise annoyance and negatively affect drivers’ subsequent responses to unrelated, critical events on the road. While performing a simulated driving task, truck drivers received two types of warnings that were designed to differ significantly in perceived urgency. Several times in the trial an unexpected event occurred just seconds after drivers were presented with an unrelated warning, and the drivers had to brake immediately to avoid a collision. The results indicate that acoustic characteristics and semantic meaning may impact the perceived annoyance of in-vehicle warnings. Furthermore, the participants who received a high-urgency warning braked significantly harder and tended to brake later than the drivers who received a low-urgency warning.

The simulator study was also used to validate the reliability of the new audio system.

The purpose of this study was, through the use of interviews, case studies, and a reference group meeting to describe and analyze the implementation process of new and revised regulations. This applies to both road and track in their administrative and operational activities within the Swedish Transport Administration and their contractors. The aim was also to analyze the effects the new and revised regulations had on roles and responsibilities but also their own and others' safety. For work on the road, new rules and regulations were established, which became effective as of 1st of January 2013. With regard to rail, a number of measures were implemented in 2011 to improve safety that included changed rules for work on and beside the tracks.

Motion base driving simulators have limited space in which to recreate the motions of the simulated road vehicle. Conventional motion cueing algorithms strive to centre the cabin in the simulator motion envelope to accommodate accelerations in a worst case scenario while respecting the physical boundaries. Using information about the road ahead one can preposition the cabin to an off-centre point, virtually increasing the available space so that larger motions are made possible. The prepositioning algorithm presented here was developed as an addition to a classical motion cueing algorithm and makes use of road data and vehicle speed to adjust the simulator displacement. Simulations show that the amount of acceleration presented by an x, y-sled system can, with prepositioning, be increased by up to 25% in longitudinal and 53% in lateral direction for an example road. A comparative study including 12 test subjects indicates that the perceived realism is rated higher with prepositioning.

Fatal accidents during winter time in Sweden are to a large extent due to vehicle spinning. Therefore, it is crucial to analyse and compare vehicle/tyre performance on slippery roads with respect to oversteering. We have performed experimental tests to compare the stability performance of various winter tyres on ice, with and without an electronic stability system (ESC). Two different test methods are presented, one closed loop and one open loop test. Results from both studies are discussed, and it is clear that different tyres may have a large impact on vehicle stability even with ESC activated

Every winter in Sweden, winter roadways pose problems for heavy vehicles. Steep gradients can be difficult to pass when it is slippery, which has implications also for other traffic when congestion occurs. To reduce the problems it has been discussed whether to impose a legal requirement for winter tyres on drive axle for trucks. This papers presents test results of the available snow grip from test track measurements comparing different drive axle tyres. A summer tyre, together with three winter tyres, of which one was retreaded, were selected for tests. The results of the traction tests show that there can be a big difference in grip between winter and summer tyres on packed snow. The difference between the tyres, however, is strongly dependent on the nature of the snow surface, so it is difficult to give general values. Theoretical calculations show that a vehicle’s rolling resistance can have a major impact on a vehicles climbing ability. With a high rolling resistance, which may be the result of loose snow on the road, the difference between good and bad grip on the drive tyres becomes even more significant.

Det saknas vetenskapligt utförda studier angående hur stora skillnader i väggrepp som kan förväntas mellan vinter- och sommardäck på olika vinterväglag för kategorin tunga fordons drivaxeldäck. Då resurserna var begränsade fanns det endast möjlighet att testa ett fåtal däck. Ett sommardäck tillsammans med tre olika vinterdäck, varav ett regummerat, valdes ut för testerna. Vidare utfördes testerna på en testbana med en typ av vinterväg: packad snö.

Grepptesterna på packad snö visar att det kan vara stor skillnad i grepp mellan vinter- och sommardäck. Skillnaden mellan däcken är dock starkt beroende av snöytans beskaffenhet, varför det är vanskligt att ange generella värden. Minst skillnad mellan däcken uppmättes på riktigt hård packad snö, där vinterdäcket presterade 20 % bättre grepp än sommardäcken. Då snöytan var något mjukare och med snöfall till och från presterade vinterdäcket drygt 60 % bättre grepp än sommardäcket, vilket skulle innebära att flera fordonskombinationer skulle klara dubbelt så branta backar med det specifika snöväglaget med vinterdäck på drivaxeln jämfört med sommardäck. De båda testade snöytorna var dock båda relativt hårda och erbjöd bra grepp för alla testade däck. Vi kan inte från dessa tester förutsäga hur stora skillnader mellan däcktyperna som skulle erhållits vid tester på halare snöunderlag. Teoretiska beräkningar visar att fordonets rullmotstånd kan ha stor påverkan på hur väl ett fordon kan ta sig upp för en backe. Tjock lössnö på vägen kan därför kraftigt reducera ett fordons backtagningsförmåga. Vid stort rullmotstånd blir skillnaden mellan bra och dåligt grepp på drivdäcken ännu större.

A literature review about the road safety effects associated with tires, rims and wheels was carried out, where the literature search was done in consultation with the VTI Library and information centre. The outcome resulted in approximately 90 different references, most of which refer to research articles in peer reviewed journals, but also some independent reports and books. A clear distinction was made with slip-related accidents related to winter conditions and different types of snow tires/tire characteristics not included in the study. Furthermore, only the type of accidents that occurs during vehicle operation was treated, which means that work accidents occurring during a service are not included in the study.

There is not much research published on the rim effect on road safety, and a U.S. accident investigator believes that the wheels generally are extremely reliable. Of the anomalies that can occur for the wheel as a whole, loosening of the wheel is the most serious. The studies that we found dealing with wheel imbalance only apply to comfort problems and increased road wear. Different wheel alignment will affect a vehicle's handling, but we have not found any study that has related this to road safety. For tires, we found no research on how different tire sizes and brands mounted on a vehicle affect its safety. Several studies show that there is a risk involved with mounting new tires on the front axle and worn tires on the rear axle. There is a consensus that during the replacement of two tires, the new tires should always be positioned on the rear axle, regardless if the vehicle is front or rear wheel driven. A number of studies show how the tread depth affects the wet grip during braking, and how the tires with less than 3 mm tread depth lose about half of the available friction compared to new tires.

Active safety systems are becoming increasingly common in today's vehicles. Electronic Stability Control (ESC) systems were introduced during the end of the 1990s, and accident statistics show that they have had a huge impact on traffic safety. In the USA, a new legislation has recently been adopted which demands on every new light vehicle that is sold to be equipped with ESC, beginning 2011. New systems require new testing methods, and there is a need expressed by the New Car Assessment Program (NCAP), which at present time only evaluates the passive safety of cars, also to include tests for active safety systems. In a previous VTI work, a literature review regarding methods for the evaluation of traffic safety effects of Antilock Braking Systems (ABS) and ESC was performed. Based on the findings of that review, we have proceeded with defining a test method for evaluating safety aspects of ESC equipped passenger cars. The objective has been to suggest a (prototype) test method that can be used for a more holistic evaluation of the safety effect of ESC in cars, including the driver behaviour perspective. From discussions with leading experts on traffic safety and ESC, possible benefits of ESC systems on traffic safety were identified. In addition to increasing the yaw stability of the vehicle, the following ESC benefit effects were identified: - A warning system for slippery roads. ESC activation indication may act as a warning system to the driver about slippery road conditions. - Reduced collision speed. In a critical situation, ESC activation may reduce the collision speed, which will mitigate the outcome of the collision. - Improved vehicle roll stability. The ESC system may also stabilise the vehicle with respect to untripped rollovers. Most rollovers are however tripped rollovers, which can occur when a vehicle, with some lateral slip, strikes an object or slides off the road. These rollovers also benefit from the ESC system as it aids in keeping the vehicle on the road.

In this study we have investigated how tyres with different road grip affect the stability of passenger cars equipped with Electronic Stability Control (ESC) systems during winter road conditions. A field test with a double lane change manoeuvre on ice was performed using 6 test drivers, 4 different passenger cars and 4 different studless winter tyres. The specific tyres were chosen to represent a large difference of road grip on ice and snow. The results show that there was a large performance difference between the best and worst tyres with ESC off, and that activating ESC only resulted in a minor increase of performance.

Traffic accidents during winter time are to a larger extent categorized by loss of vehicle control resulting in a skidding accident, compared to accidents occurring summer time. In a study by the Swedish Transport Administration, it was shown that for fatal accidents happening winter time, skidding had occurred in 64 per cent of the accidents on winter road conditions. Out of these, 82 per cent were so called over steering accidents, i.e. events where the vehicle starts to spin.

The purpose of this study was to develop av method for testing a vehicle's stability during oversteering on slippery roadways, and to use this method to test how large the difference is between different kinds of winter tyres on ice and snow.

A test method based on NTHSA's sine-with-dwell manoueuvre was developed. The manouevre uses a steering robot and induces heavy oversteering on slippery surfaces, such as ice and snow.

The manouevre was then used with an ESC equipped rear-wheel driven passenger car, fitted with both new and worn winter tyres of the three different kinds that are available in Sweden, to compare the level of oversteering that is possible to obtain with a steering manouevre on different ice and snow surfaces. The results show that studded tyres are more stable than unstudded on smooth ice. Even the worn studded tyre, with only a fraction of the studs remaining, is performing well compared to the unstudded tyres, and is comparable to a new unstudded winter tyre of Nordic type and much better than the tyres of Central European type. The winter tyres of Central European type stand out as those generating most oversteering on this surface. On surfaces with higher friction level, the tyres with least grip are also those that generate least oversteering, which makes it difficult to discuss these results in terms of traffic safety.

Fatal accidents during winter time in Sweden are to a large extent due to vehicle spinning. Therefore, it is crucial to analyse and compare vehicle/tyre performance on slippery roads with respect to oversteering. In this study, a new test method for evaluation of vehicle's stability during oversteering on icy roadways is developed and evaluated using a series of tests with a rear wheel driven car, equipped with ESC, and six different tyres on ice test tracks in northern Sweden. The test method consists of an asymmetric sine-with-dwell manoeuvre and a measure forquantifying the level of oversteering based on the relation between yaw rate and lateral acceleration. The test results show good robustness of the method, and that it can successfully rate the various tyres performance on polished ice. However, to have a fair comparison, the proposed method should be modified to take into account the steering ability of the tyres and the consequent difference in the manoeuvre severity when tested with tyres with different side grip.