Support Systems Designed for Older Drivers to Achieve Safe and Comfortable Driving

Background: The number of older people is increasing. Many of them expect to maintain a rich social life and to continue driving at an older age. Objective: The present study investigates the mechanisms behind self-regulation and driving cessation in order to suggest development of support systems to prolong older drivers’ safe mobility. Method: Three focus groups were conducted with 19 older active drivers aged 65+ who were divided according to annual mileage driven. Results: A content analysis revealed broad self-regulatory behaviour as already reported in the literature, e.g., avoiding driving at rush hour and at night. The participants also reported difficulty in finding the way to their final destination and an increasing need to plan their travelling. Co-piloting was a behaviour applied by couples to cope with difficulties encountered in traffic. A large part of the discussion was focused on emerging feelings of stress, anxiety and fear when driving in recent years, a feeling induced by external factors e.g., other road users’ behaviour, traffic density or high speed. Apart from health problems, high levels of stress could explain driving cessation, especially for women. An increased feeling of safety and comfort could be achieved by an increased use of support systems specifically designed to respond to older drivers’ needs. Conclusion: Support systems for older drivers should increase comfort and decrease their stress levels. New systems, such as co-pilot function and more developed Global Positioning System (GPS) supporting of the entire travel from door to door, should be developed to respond to the market needs.

Influence of Road Wetness on Tire-Pavement Rolling Resistance

Rolling resistance of tires is one of the most important factors influencing energy consumption of road vehicles, especially on rural roads. For practical reasons, most of rolling resistance measurements are usually performed for dry road conditions. Based on the fact that roads are wet during a considerable time over the year and as part of the projects MIR/AM, ROLRES and ROSANNE, the TUG （Technical University of Gdafisk） in Poland and VTI （Swedish National Road and Transport Research Institute） in Sweden carried out trailer rolling resistance measurements on wet road surfaces to investigate water film influence on rolling resistance on different pavements. A specially-designed trailer to measure rolling resistance has been used. The test sections were both rural roads and an abandoned airfield equipped with water film sensors mounted in the pavement. Results indicate strong influence of test speed and water film depth, as well as influence of surface texture. The increase of rolling resistance on wet surfaces is caused by both hydrodynamic phenomena and cooling effect of water that decreases tire temperature thus increasing rolling resistance.

Weak central coherence in patients with Alzheimer’s disease

Central coherence refers to the ability to interpret details of information into a whole. To date, the concept of central coherence is mainly used in research of autism, Asperger＇s syndrome and recently in the research on eating disorders. The main purpose of the present study was to examine central coherence in patients with Alzheimer＇s disease. Nine Alzheimer＇s disease patients and ten age- and gender-matched control subjects, who differed significantly in neurological assessment, were shown a picture of a fire. Compared to control subjects, the Alzheimer＇s disease patients described the picture in a fragmented way by mentioning details and separate objects without perceiving the context of the fire. In conclusion, patients with Alzheimer＇s disease are at the weak end of central coherence, and hence suffer from a fragmented view of their surroundings. The findings have important clinical implications for the understanding of patients with Alzheimer＇s diseaseand also for the possibility of caregivers to meet the Alzheimer＇s disease individual in an appropriate way in the everyday care.

Effective and Sustainable Flood and Landslide Risk Reduction Measures:An Investigation of Two Assessment Frameworks

Natural events such as floods and landslides can have severe consequences.The risks are expected to increase,both as a consequence of climate change and due to increased vulnerabilities,especially in urban areas.Although preventive measures are often cost-effective,some measures are beneficial to certain values,while some may have negative impacts on other values.The aim of the study presented here was to investigate two frameworks used for assessing the effectiveness and sustainability of physical and nonphysical flood and landslide risk reduction measures.The study is based on literature,available information from authorities and municipalities,expert knowledge and experience,and stakeholder views and values.The results indicate that the risks for suboptimization or maladaptation are reduced if many aspects are included and a broad spectrum of stakeholders are involved.The sustamability assessment tools applied here can contribute to a more transparent and sustainable risk management process by assessing strategies and interventions with respect to both short- and long-term perspectives,including local impacts and wider environmental impacts caused by climate change,for example.The tools can also cover social and economic aspects.The assessment tools provide checklists that can support decision processes,thus allowing for more transparent decisions.

Study of industrially applied methods for verification, validation and uncertainty quantification of simulator models

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.

ERTMS/ETCS Level 3:Development,assumptions,and what it means for the future

The purpose of this paper is to categorize the research on Level 3 and Hybrid Level 3;map how the research focus on ERTMS Level 3 has developed over time;summarize key assumptions in research on Level 3 and Hybrid Level 3.This study uses a scoping review approach.This review method provides a comprehensive overview of the literature in a selected field.The literature searches in this study were primarily conducted in Scopus and Web of Science and were complemented with a follow-up search in Google Scholar.The topics are divided into two thematic areas:Effects on the Railway System and Technical Requirements.The thematic area Technical Requirements is further divided into the following subcategories:train,trackside,and communication.The effects on the railway system are measured using performance indicators:capacity,stability/robustness,and safety.ERTMS Level 3 has developed from a pure Level 3 to Hybrid Level 3.Hybrid Level 3 represents a pragmatic solution,but it may emerge as a threat to the long-term objective of the Level 3 moving block.Studies of Level 3 are based on a moving block solution,while studies of Hybrid Level 3 are mainly based on virtual sub-sections.Both Level 3 and Hybrid Level 3 studies tend to make assumptions that risk missing wider aspects of the railway system.There is also a need to correctly represent different ERTMS Level 3 configurations to ensure expected capacity gains.For a better understanding of the development and future path of ERTMS Level 3,it is interesting to study the following aspects:the historical development of ERTMS Level 3 research,the assumptions made about ERTMS Level 3,and the conditions and restrictions under which ERTMS Level 3 will be implemented.Assumptions and simplifications are necessary for modeling work,but there is also a need to highlight underlying assumptions in analyses of different ERTMS Level 3 configurations.

Determination of riding comfort on cycleways using a smartphone application

Well maintained cycleways will encourage more people to cycle,as the condition of cycleways is important for the safety,accessibility and riding comfort of cyclists.Despite that,only a few models used to describe the quality of service for cyclists take the surface condition into account.Objective measuring methods are needed to enable reliable and effective assessment of surface conditions,and measurable performance criteria related to the needs of cyclists should be developed.The purpose of this study has been to test the reliability and validity of using accelerometers in smartphones to assess the riding comfort on cycleways.A smartphone application converting three-dimensional accelerometer measurements into a single indicator for cycleways has been used to assess road surfaces in two field studies,in Sweden and Norway,respectively.Both studies assessed test sections of varying quality.To relate the measurements to subjective riding comfort assessments by cyclists,recruited cyclists collected quantitative data using the app,whilst also rating their perceived riding comfort by completing a survey.Measurements were also related to standard road surface condition indicators,generated from a road surface tester equipped with 19 laser sensors:international roughness index(IRI),mega-and macrotexture.The results show that it is possible to describe the unevenness of a cycleway using the technology present in smartphones.A software application can be used to collect and analyse data from the acceleration sensors in the phone,which can then be used to describe the riding comfort of cyclists.It is mainly the unevenness in the 50-1000 mm sizerange that create the greatest discomfort for cyclists,and intermittent vibrations are perceived as more uncomfortable than more evenly distributed vibrations.Therefore,IRI is not a relevant measurement for describing the riding comfort of cyclists.

Influence of morphology on high-temperature rheological properties of bitumen modified with styrene-butadiene-styrene(SBS)copolymer

Different microstructures of the same polymer-modified bitumen(PMB)were obtained by subjecting the bitumen modified with styrene-butadiene-styrene(SBS)copolymer to isothermal annealing at various temperatures.The effects of the morphology on the rheological properties of SBS-modified bitumen were investigated within the hightemperature range.The PMB microstructures were quantitatively evaluated using image analysis.A dynamic shear rheometer was used to measure the rheological parameters of the PMB samples and perform the multiple stress creep and recovery(MSCR)test.A quantitative basis could be established on which to discuss the relationship between the PMB morphology and rheology.The image analysis indicated that conditioning by isothermal annealing evidently led to a difference in the microstructure of the samples.Variation of the thermal history is demonstrated to be a practical way to vary the morphology of the PMB with the same raw materials and formulation.Compared with the two-phase morphology,the single-phase microstructure tended to have a narrower linear viscoelastic(LVE)region of the PMB.Within the LVE region,especially at low frequencies,the homogenous PMB can store more energy when experiencing loadings and is more elastic.Outside the LVE region,based on the MSCR test results,the homogenous morphology could assist in reaching a higher percentage of strain recovery after the creep period.

Behavioral adaptation of drivers when driving among automated vehicles

Purpose–This paper aims to explore whether drivers would adapt their behavior when they drive among automated vehicles(AVs)compared to driving among manually driven vehicles(MVs).Understanding behavioral adaptation of drivers when they encounter AVs is crucial for assessing impacts of AVs in mixed-traffic situations.Here,mixed-traffic situations refer to situations where AVs share the roads with existing nonautomated vehicles such as conventional MVs.Design/methodology/approach–A driving simulator study is designed to explore whether such behavioral adaptations exist.Two different driving scenarios were explored on a three-lane highway:driving on the main highway and merging from an on-ramp.For this study,18 research participants were recruited.Findings–Behavioral adaptation can be observed in terms of car-following speed,car-following time gap,number of lane change and overall driving speed.The adaptations are dependent on the driving scenario and whether the surrounding traffic was AVs or MVs.Although significant differences in behavior were found in more than 90%of the research participants,they adapted their behavior differently,and thus,magnitude of the behavioral adaptation remains unclear.Originality/value–The observed behavioral adaptations in this paper were dependent on the driving scenario rather than the time gap between surrounding vehicles.This finding differs from previous studies,which have shown that drivers tend to adapt their behaviors with respect to the surrounding vehicles.Furthermore,the surrounding vehicles in this study are more“free flow’”compared to previous studies with a fixed formation such as platoons.Nevertheless,long-term observations are required to further support this claim.