This report describes the work of work packages 6 and 8 in the Vinnova-funded Smarta gator project. Based on architectural descriptions, three different VR environments have been created – so-called “digital twins” of a currently existing street environment in Stockholm, as well as two different possible future versions of the street environment. The simulated environment can be experienced by pedestrians in VTI’s pedestrian simulator, and alternatively also by motorists through co-simulation with another driving simulator. The two possible visions for the future were evaluated from a pedestrian perspective through a workshop with 30 subjects in VTI’s pedestrian simulator in Linköping. The participants’ answers clearly show that the experience of security, priority and well-being increased in the smart environments compared with the original environment. 

However, the readability of the street space was experienced in the smart environments somewhat degraded compared to the original environment. One explanation may be that many people recognize the original environment because it is a relatively common type of street – wide lanes for cars, curbside parking and sidewalks, while the smart environments are structured in a different way, which may need additional experience to understand this “new type” of street. 

Overall, the study demonstrates how street spaces can be created that are experienced as more pleasant and safer by prioritising pedestrian and bicycle traffic through a larger area dedicated to walking, cycling and accommodation than for motor traffic. The creation of living spaces and social functions along the street also had a positive effect on the experience of the street space. Placing trees and greenery along the street is in addition to the ecological benefits also important for the well-being and experience of the street space. 

It is concluded that VR simulation can be a useful tool for assessing various design solutions at an early stage. VTI’s pedestrian simulator is equipped with a state-of-the-art image system, but the restricted area of 3x6 meters is too small to allow for a person to easily walk around the urban environment. Autonomous pedestrians, controlled by the game engine Unreal Engine, were perceived by most subjects as very realistic, and they contributed to the illusion of being in place in the environment.

Simulation has become a useful tool for vehicle manufacturers in the design and assessment of new vehicles. Using an advanced driving simulator in early design phases may reveal defects in the construction, which otherwise would not be noticed until full scale prototyping, and thereby reduce development time and costs. In most driving simulator studies the road design does not have to conform to an existing road. But for some purposes it may be crucial that the virtual road describes the real road as close as technically possible. Examples are vehicle vibration studies, fuel consumption evaluation with respect to driver behaviour, and comparisons between driving on the virtual and real road. The required level of detail of different road features varies between applications (projects). Parameters like road curvature, inclination, elevation and crossfall, the surrounding terrain as well as road imperfections and unevenness may be of more or less importance and therefore have to be modelled with high or lower accuracy. In the Known Roads project, a real road, the “Gothenburg triangle” (Gothenburg-Borås-Alingsås- Gothenburg), was modelled as realistically as possible. Road curvature, inclination and crossfall as well as the surrounding terrain were considered important. This White Paper is complementary to other deliverables from the Known Roads project. It presents in more detail the method of recreating existing roads in a simulation environment, developed by VTI in the project. The White Paper concerns specifically the difficulties of merging different data sources into a road representation, and describes the problems that were encountered and the solutions that were developed for implementing an existing road in the driving simulator.

The VTI simulator IV (Sim IV) is the fourth advanced driving simulator designed and built at The Swedish National Road and Transport Research Institute (VTI). The simulator, taken into operation 2011, has an 8 degrees of freedom (DoF) moving base, a field of view (FoV) of 180 degrees and features a system for rapid cabin exchange. With a budget of roughly 2,4 M euro; Sim IV was developed to provide VTI’s newly established Gothenburg office with advanced driving simulation capability, and to be a cost efficient complement to the Sim II and Sim III facilities in VTI’s Linköping office. This paper describes the design and technical performance of the facility. A brief summary of results and experience from validation studies for the first three years of operation is also presented.

To address the research questions, acritical lead vehicle braking scenario and anFCW system was developed and pilot tested in Saab’s fixed based driving simulator in Trollhättan. After piloting, the scenario was implemented in VTI’s moving base simulatorin Linköping, and the effects,of FCW presence, two different initial time headways at visual distraction task onset and repeated scenario exposure, on driver response timeswere examined.The study showed significant effects of FCW and repeated scenario exposure on response times. Moreover, these effects were not additivei.e. a significant interaction between the two was found. There was also a significant effect on responsetimes ofinitial time headway at onset of the visual distraction task. In addition, an interaction between initial time headway and repeated scenario exposure was found for drivers with FCW, but not for drivers without FCW. A second objective of the project was to compare the extent to which the VTI moving base simulator with motion cues generates similar driver responses(quantitatively and qualitatively)as the static simulator set-up at Saab. In general, theresults from this project have important implications for the interpretation of driver performance in experimental settings, particularlywhen aiming toevaluate safety-related in-vehicle information and warning technologies. For onething,they pose a general question markaround the generalizabilityof results to real world events. Second, a future prerequisite for FCW studies should probably be that test drivers have a previous level of system exposure level which matchesthat of real world drivers encountering typical critical events. Also, tuning the initialtime headwayat distraction task onsetin the experimentalsetting to real world conditions is of critical importance.

This publication presents a project aiming to develop virtual representations of real roads for use in driving simulators. The development was done in order to enable assessments of new systems on existing and well known roads in a driving simulator, and will increase the external validity of virtual testing. Furthermore, the usage of the virtual model of such roads makes the simulator results better comparable to earlier performed or later following road tests. The roads connecting Göteborg-Borås-Alingsås-Göteborg were selected. The purpose for this is due to their proximity to the vehicle industry in west Sweden and to the test tracks “Hällered” and “AstaZero”. However, the tools and methods developed can be used to build a virtual representation of any other road through a surrounding landscape and/or more urban environment. The project was carried out in steps, starting with data collection (investigation and assessment of available data from different sources as well as measurement of road properties) followed by data treatment (remove irrelevant data and errors, filtering, etc.), modelling (mathematical description of road properties) and simulation (selection of data formats for real time simulation).

By the year 2018, the Climate Act will come into force. By 2030, climate impact in the transport sector should have fallen by 70 percent compared with 2010 and by 2045 Sweden’s climate impact will be net zero. This means a fundamental transformation of the energy supply of vehicles in road transport. For buses in city traffic, electrification is favorable because electric buses are both exhaustfree and quiet, giving a lesser environmental impact in the street environment, and by that the possibility of creating attractive bus lines.

To exemplify how a bus electrification can be done, a driving simulator study was conducted on a possible electric bus line in the city of Lund using an electric road system. The goal of electrification was to achieve a high user acceptance and to meet the targets for the future environment and energy use.

With the help of various sources of information about electric buses, electric road systems and the urban environment of Lund, virtual models were created, which were then installed in the driving simulator.

To evaluate whether the bus and electrification complied with the user acceptance requirements, bus drivers participated in a test in a dynamic driving simulator, SIM II at VTI in Linköping. The results showed that the drivers had no major difficulties in driving the bus so that the electrification worked. Unfortunately, some of the drivers suffered from sickness while driving (“simulator sickness”) and had to stop driving.

An evaluation of the driving simulator used as a tool for public relation purposes was made by providing an information sheet and demonstrating the electrification to employees in Lund municipality by using a small, moveable driving simulator. Interviews about electric buses and electrification were made before and after the demonstration to see effects on the opinion and understanding of electric buses and electric road systems. The results showed that the simulator drive gave added value in addition to the information sheet only, 2/3 of the participants answered that their understanding was increased by the simulator drive and 1/3 answered that it was not changed. The attitude to the electric bus and the electric road system did not change. Most people considered that the simulator could be a helpful tool in decision making.

An analysis of the energy consumption of the bus showed that the battery level was lower at the end of the test drive than in the beginning, i.e. the battery level dropped. This would not have been the case if the electrification had been made more advantageously, and thus would not need to be a limiting factor in future implementation.

In addition, the studied electric road system was compared with some other power supply options such as charging at bus depot and at bus end stop. The pros and cons of these alternatives were discussed based on economic and bus operational perspectives.