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The knowledge overview deals with simulator sickness, for example, why it occurs, the symptoms, and what measures can alleviate the symptoms. Image systems which extend a long way sideways, 90º turns and rapid changes of speed are examples of factors which can give rise to simulator sickness. The effect of movement is less clear, positive effects and the lack of effects have both been observed. There are also individual differences, including sex and age, which can affect sensitivity to simulator sickness. By excluding tight bends, complex environments, start and stop situations in the scenarios, the frequency of simulator sickness is reduced. In short exposures, there is less risk of simulator sickness occurring. Repeated exposures can result in the trial participants getting used to the simulator environment. Also, persons who do not consider themselves to be at all sensitive as regards motion sickness can be affected by simulator sickness, for which reason, previous experience of motion sickness is not a good predictor of simulator sickness. Experience of simulator sickness in VTI's research simulator is summarised. The problems have been reduced, largely thanks to simulator design. Finally, relevant aspects are discussed as regards the planning of a study of simulator sickness in a VTI simulator.

Mätfordonet Laser RST har tillsammans med annan Laser RST-teknik använts för mätning av vägytans tillstånd på tre vägar med betongbeläggning i Sverige och Norge. Laser RST är ett mätsystem som medger samtidig mätning av tvärprofil, jämnhet i längsled, textur, sprickor, tvärfall, kurvatur och backighet. Dessutom finns möjlighet till manuell inmatning av information via en knappdosa. Mätning har också gjorts med VTI:s statiska tvärprofilmätare (TVP) för tvärprofilmätning, en 64 kHz laseravståndsmätare för mätning av fogarna mellan betongplattorna och PAVUE-systemet för noggrann sprickdetektering. De genomförda mätningarna har påvisat nyttan av att med hjälp av Laser RST regelbundet följa upp tillståndet hos högt trafikbelastade betongvägar. Sålunda kan på basis av insamlade mätdata den funktionella kvaliteten hos vägytan kvantifieras och tillståndsutvecklingen bedömas.

Low frequency vertical accelerations can provoke motion sickness and nausea in ships and aeroplanes and probably, combined with horizontal (lateral) acceleration, also in cars and buses. However, tilting trains and banking aeroplanes generate roll motions, which may provoke motion sickness in motion sickness sensitive humans. Some seventy healthy volunteers were employed. They were tested in a high speed tilting train (X2000) with three different tilt control strategies during three days. Different ratios of tilt compensation were used. The test rides lasted about three hours. Four times per test ride the subjects answered a questionnaire concerning comfort and discomfort. The train motion environment was monitored and recorded during the test rides. Motion doses, for prediction of motion sickness, were calculated from vertical and also from lateral and roll accelerations for the different parts of the test track. The conditions with 55% ratio of tilt compensation instead of the normal 70%, reduced the discomfort from about 15% to about 8–10%. No reduction of subjective ride comfort or working ability was recorded in these conditions with 55 % compensation. Discomfort correlates fairly well with motion dose of roll acceleration but not with vertical or lateral motion doses. This means that an optimised tilt control system should reduce the motion dose from roll acceleration in order to minimise provocation of motion sickness. On the other hand, too small compensation ratios will cause discomfort by too large lateral accelerations.

Efficient and well-maintained road systems are necessary for the economic well being of any industrialized country. Maintenance and rehabilitation of existing roads have taken priority over new construction in recent years, thus making information about the condition of road surfaces extremely important. Several methods of gathering this information have been developed worldwide; one of them is Laser Road Surface Tester (Laser RST), which was developed in Sweden in 1981. The Laser RST is a laser-based, computer-automated, non-contact road profilometer system with the ability to collect and simultaneously process data about the road surface. Variables measured include rut depth, unevenness, cracking, megatexture, rough macrotexture, fine macrotexture, crossfall, curves, and elapsed distance. Subjective evaluations are also supported, if desired. Eleven laser rangefinders (LRFs), mounted on the front of the Laser RST van, are the primary components of the data collection system. They scan the road with high-speed, high-resolution distance sampling. The signals from the lasers are sent through signal processing cards (SPCs) and then to a computer inside the van for final processing. Data is stored on floppy disk and printed by an on-board printer. The Laser RST is an extremely complex system but it is also a modular one, making troubleshooting and repair relatively easy, inexpensive, and fast. This paper discusses the various modules available. Variables measured are defined and measurement algorithms detailed. The Laser RST system can be customized to meet specific user requirements quickly and easily.