There are few references in research on the therapeutic relationship that explicitly deals with the psychotherapist's emotions in the relationship. The purpose of this study is to understand more about the psychotherapist's emotions, what triggers them in the therapy relationship and the perceived risks and opportunities with their feelings.  A qualitative methodology with an explorative approach was used for this study. Participants in the study are six psychotherapists; four women and two men, aged 50-65 years. The result shows that psychotherapists do not connect strong feelings in relation to the positive outcome in therapy. They express that as a psychotherapist one should be observant of one´s feelings and that the feelings should be kept in the background of the relationship. In the therapies that participants refer to in the interviews, the results has been good, the patients have been perceived as genuine and the psychotherapists have felt genuinely liked by the patient. Participants do not connect positive treatment outcome and authenticity of the patient in the therapy relationship. Authenticity also among the psychotherapist, both self-knowledge and professional skills are important factors for the performance of the therapeutic work. 

A widely held view is that top-down modulation of sensory information relies on an amodal control network that acts through the thalamus to regulate incoming signals. Olfaction lacks a direct thalamic projection, which suggests that it may differ from other modalities in this regard. We investigated the late positive complex (LPC) amplitudes of event-related potentials (ERP) from 28 participants, elicited by intensity-matched olfactory, auditory and visual stimuli, during a condition of focused attention, a neutral condition, and a condition in which stimuli were to be actively ignored. Amplitudes were largest during the attend condition, lowest during the ignore condition, with the neutral condition in between. A Bayesian analysis resulted in strong evidence for similar effects of task across sensory modalities. We conclude that olfaction, despite its unique neural projections, does not differ from audition and vision in terms of task-dependent neural modulation of the LPC.

Retirement is something all workers will face sooner or later. The purpose of this qualitative interview study was to investigate the subjective experience of the transition between working life and retirement of retirees, and workers in the transition phase as well as how the physical, mental and social health is affected by retiring. The purpose was investigated through twelve semi-structured interviews, which were analyzed using a thematic content analysis. The participants consisted of nine men and three women, who represented a pensioner activity and a company in a smaller city in the south of Sweden. There were six participants in each group. The thematic analysis resulted in three themes, which responded to the purpose of the study: Ambivalent curiosity, Relationships and Health. Subthemes have also been identified; Role conflict, Own terms, Engagement, To feel meaning and Activities. The participants had different experiences regarding the transition phase and the adaptation to retirement, and an ambivalent curiosity emerged. The participants further felt that relationships were important and functioned as support during and after the transition, and good health was a key factor for a successful retirement. Overall, the results were consistent with previous research.

The purpose of this study is to see if there is a relationship between health-promoting leadership and employee’s well-being. According to the hypothesis, and with knowledge in the field, individuals with high well-being should experience health-promoting leadership. The study was conducted with quantitative method using a questionnaire survey. Study participants consisted of 63 employees from health-care in southern Sweden. Results shows that there is a correlation between health-promoting leadership and employee’s well-being at the investigated workplace. The result in our study indicates that the correlation that earlier research concluded about health-promoting leadership and well-being is confirmed. However, future research should focus on making the link between health-promoting leadership and well-being clearer to gain further understanding of how the relationship works.

Stress is both a health risk and an economic risk for our society. Employers search for ways to offer possible stress reducers for their employees. Mindfulness as a stress reducer is a fairly new research area but with a good amount of research papers suggesting that mindfulness programmes over several weeks are successful in reducing subjective perceived stress as well as physiological stress, such as blood pressure and cortisol levels. This study aims to examine whether mindfulness could show positive effects on stress at work, after only one mindfulness session, compared to being on an extended break. Measurements includes the Shirom-Melamed Burnout Questionnaire (SMBQ), blood pressure and pulse. The results show that engaging in one single mindfulness session does have an effect on lowering blood pressure as well as lowering perceived tension, which is one of four parts of the SMBQ. 

Several hundred new synthetic drugs, novel psychoactive substances (NPS) or “legal highs” have in recent years appeared on the drug market. These can effortlessly be obtained from on-line vendors, offering an easy access to a plethora of new and untested substances, often with unknown or dangerous effects. Several different attempts to reduce the availability of NPS and to prevent accidents and fatalities have been applied by governments around the world. Nonetheless this complex and constantly evolving situation provides palpable dilemmas and challenges to legislators and prevention strategists. One unintended consequence from prohibition and current drug policies occurs when possibly more precarious substances are used to substitute older and more well-known illicit drugs; so called “substance displacement”. We have performed extensive research on the use of NPS, by analyzing Internet resources (drug discussion forum, on-line questionnaires), and published several NPS studies. During our research we observed how substance displacement is a common issue, with implications for both clinical practices, drug prevention strategies, as well as for legislators. In the present review we discuss two common themes of substance displacement: 1) Synthetic cannabinoids replace herbal cannabis, and 2) Different attempts for self-medication using NPS. Incitements for substance displacement, that exposes the user to possibly more harmful substances, are founded both in legislation (availability of substances and fear of legal repercussions) as well as from certain policies or cultural perceptions of various medical conditions. We offer no obvious solutions to these complications, but would like to contribute to awareness of how these factors effects drug users and how measures intended to reduce harm in many cases have the opposite effects. Further studies on the divergent motivations and different groups of NPS users are highlighted as imperative to find new and realistic solutions going forward. 

Aim: The purpose of this qualitative study was to investigate the effects experienced by users of a novel psychoactive substance, the benzodiazepine flubromazolam, by analysing users' own accounts on the Swedish forum Flashback.org. Method: A thematic analysis of anonymous self-reports published on the forum was performed and generated five general themes describing effects and experiences by flubromazolam users. Results: The themes which emerged were: Onset and duration, Desired effects, Adverse effects and addiction, Loss of control, General estimations and evaluations. The main reported characteristics of flubromazolam were heavy hypnotic and sedative effects, long-lasting amnesiac effects and the rapid development of tolerance. Flubromazolam was also anxiolytic and acted as a muscle relaxant for many users. Some users experienced euphoria or intense wellbeing. Other prominent characteristics were loss of control (leading to poor choices and actions, with unpleasant consequences) and long-lasting, often severe withdrawals. There were also serious incidents where users had been admitted to hospital, acute psychiatric treatment or taken into custody by the police. Conclusion: Flubromazolam appears to be a highly addictive and precarious benzodiazepine with many, possibly severe, side effects. The substance is generally described as very potent and with long-lasting effects. Memory loss and loss of control are common adverse effects, and withdrawals appear to be severe for many users

In recent years, there has been an increased popularity in games with permanent death. This thesis investigates what mechanics makes the player return after continuously losing in permanent death games. The mechanics of four bestselling games featuring permanent death, which implies the complete restart of the game each time the player avatar dies, are played for six hours and analysed. The games analysed are Binding of Isaac: Rebirth, Spelunky, Rogue Legacy and Don‟t Starve.  

Based on the mechanics found in the games and using Raph Kosters definition of fun, “if games stop teaching us they become boring”, it is established that a number of different reasons exist to bring a player back, not just necessarily only the mechanics themselves.

Background

Sustaining multiple concussions over one’s lifetime may be associated with behavioral and mood changes beyond the acute phase of injury. The present cross-sectional study examined the relationship between concussion history, the incidence of current moderate-severe psychological distress, and lifetime adolescent hazardous gambling in high school students.

Methods

Four-hundred fifty-nine high school students from southern Sweden (age: 16.81 ± 0.83, 58.2% male) completed a survey assessing concussion history (0,1,2…>8), psychological distress using the Kessler-6 scale, and lifetime hazardous gambling using the NODS-CLiP scale.

Results

Participants who self-reported three or more concussions were more likely to endorse moderate-severe symptoms of psychological distress than those with no concussion history while controlling for covariates, OR = 2.71, 95% CI [1.19, 6.18]. In contrast, concussion history was not associated with hazardous gambling after controlling for confounding variables.

Conclusions

Self-reporting three or more concussions was associated with increased current psychological distress beyond the acute phase of injury among high school students. Adolescents who have sustained multiple concussions should undergo mental health evaluations beyond the acute phase of injury to identify and treat psychological distress, but probing for hazardous gambling may not be clinically relevant in this previously concussed adolescent population.

Background: Some studies suggest that elite athletes experience adverse mental health symptoms at rates commensurate with the general population, despite the well-established buffering effects of exercise. Within contact sports, such as ice-hockey, recurrent concussions may be a source of this discrepancy. We compared the point prevalence of various mental health outcomes with other athlete and general population samples, as well as investigated their relationship with concussive events.

Methods: We surveyed 648 active ice hockey players from the top two men's tiers and the top women's tier in Swedish elite ice hockey on lifetime concussive events, hazardous alcohol use, problematic social media use, depression, anxiety, and burnout.

Results: Hazardous alcohol use was more prevalent among male ice hockey players (29.5% AUDIT-C ≥ 6) compared to other athlete and general population samples, while other mental health symptoms were less common. Female ice hockey players reported higher hazardous alcohol consumption (36.4% AUDIT-C ≥ 4) than another athlete sample and more burnout (19.1%) than the general population. After adjusting for covariates, athletes with 3+ concussive events had 2.1 times the odds of elevated depressive symptoms and 3.5 times the odds of elevated burnout symptoms compared to those with no concussion history. Treating lifetime concussive events as a continuous predictor revealed positive correlations with all outcomes except for hazardous alcohol use.

Conclusions: Mental health outcome rates among active elite ice hockey athletes differ from those of other athlete and general population samples, whilst concussive events may be particularly linked to elevated symptoms of depression and burnout.

Jobblabb är en ny utställning på Arbetets museum i Norrköping som tar emot skolklasser i årskurs 5 med syftet att hjälpa barnen att kunna fatta smarta framtida val kring jobb genom att hjälpa dem att förstå sina styrkor och hur de kan användas liksom att inspirera och visa bredden av de möjligheter som finns för dem. Den här studien utvärderar utställningens påverkan på jobbrelaterad kreativitet, specifikt att kunna komma på många och olika typer av jobb som man anser skulle kunna passa en själv i framtiden. Utvärderingen sker genom en variant av Guilfords Alternative Uses Test med mätningar av flöde, originalitet, flexibilitet, och utarbetning. Resultatet kunde inte visa några signifikanta skillnader på flöde, flexibilitet, eller utarbetning mellan de som hade respektive inte hade besökt museet, men däremot en signifikant lägre originalitet hos de som besökt museet.


Stressade medarbetare kostar pengar, sänker produktivitet och bidrar till ohälsa. Genom perspektivtagande kan vi ändra förhållningssätt till vårt psykologiska innehåll. ”Självet-som-kontext” ingår i ”psykologisk flexibilitet” och innebär att ta perspektiv till sitt psykologiska innehåll. ”Prosocialt hjälpbeteende” är att ta ett nytt perspektiv till andra. Vår studie undersöker om interventioner i självet-som-kontext och prosocialt hjälpbeteende har effekt på psykologisk flexibilitet i arbetslivet, självupplevd stress samt självet-som-kontext. Även sambandet mellan beroendevariablerna undersöktes. Vi använde en mixad AB-design med intervention. Resultatet visade på minskad självupplevd stress (p=.005) utan effekt av interventionerna (p=.771). Vi fann skillnad mellan interventionerna på psykologisk flexibilitet i arbetslivet (p=.037), men förändringen var inte signifikant (p=.597) Effektstorleken för samtliga skillnader var låg (η2p = .1). Samtliga beroendevariabler korrelerar signifikant (p=<.001).

Depression is a widely spread disorder. Cognitive training could be a

cost effective and easily accessible intervention to treat the disorder in

an early stage. Previous research indicates that cognitive training is

effective in alleviating depression and cognitive deficits. The aim of

this study was to investigate whether cognitive training at home would

lead to improvements in depression, and whether improvements were

due to the training per se. Four subjects with depression participated

in training with the Paced Audity Serial Addition Task (PASAT). The

study had an n=1-design with pre- and post-measures, and control by

a pseudo-intervention. Daily and weekly measures showed effects

only for one participant. Thus the training was not shown to be

effective. Three participants experienced benefits from the

intervention. That could be a reason for further studies of cognitive

interventions of depression.

Ongoing urban exploitation is increasing pressure to transform urban green spaces, while there is increasing awareness that greenery provides a range of important benefits to city residents. In efforts to help resolve associated problems we have developed a framework for integrated assessments of ecosystem service (ES) benefits and values provided by urban greenery, based on the ecosystem service cascade model. The aim is to provide a method for assessing the contribution to, and valuing, multiple ES provided by urban greenery that can be readily applied in routine planning processes. The framework is unique as it recognizes that an urban greenery comprises several components and functions that can contribute to multiple ecosystem services in one or more ways via different functional traits (e.g. foliage characteristics) for which readily measured indicators have been identified. The framework consists of five steps including compilation of an inventory of indicator; application of effectivity factors to rate indicators' effectiveness; estimation of effects; estimation of benefits for each ES; estimation of the total ES value of the ecosystem. The framework was applied to assess ecosystem services provided by trees, shrubs, herbs, birds, and bees, in green areas spanning an urban gradient in Gothenburg, Sweden. Estimates of perceived values of ecosystem services were obtained from interviews with the public and workshop activities with civil servants. The framework is systematic and transparent at all stages and appears to have potential utility in the existing spatial planning processes.

There are many studies conducted on cognitive performance and of different aspects that can affect the performance. However, the literature review reveal that there is a knowledge gap in the area of measurements for bicycle stability and in how bicycle stability is affected during acute alcohol intoxication. The aim of this study is, therefore, to investigate if different group characteristics such as cycling experience, physical activity, sensation-seeking, or previous alcohol habits have an effect on bicycle performance or executive functions during acute alcohol intoxication. The method of the study was to measure stability while bicycling on a tread-mill and give participants doses of alcohol until a Breath alcohol concentration (BrAC) level of approximately 0.8‰ was reached. The results showed that cognitive performance was almost unaffected for the different groups studied. The results of bicycle stability were almost equal in effect of time among the four different group characteristics in both Roll and YAW measurements. Three of the group characteristics showed a main effect or a tendency for interaction effect of group by time. The conclusion is that the measure of Roll, the vertical orientation on a bicycle, maybe is the most effective stability measurement for bicycles.

Introduction: The therapeutic alliance is considered an important factorregardless of therapeutic technique or theory. This essay discusses the affectivefocusedpsychotherapeutic method named Intensive short-term dynamicpsychotherapy (ISTDP) with focus on the therapeutic alliance. The aim of thisstudy is to examine how psychotherapists experience and describe the therapeuticalliance in ISTDP.

Issues: How do psychotherapists experience and describe the therapeutic alliancein ISTDP?

Method: The data collection method is qualitative semi-structured interviews.The material was analysed by using the processing method of empirical thematicanalysis.

Results: The result of the interviews are first presented by the informants´descriptions of the therapeutic alliance in ISTDP, followed by five emergingthemes; Responsiveness, Tempo/Pace, Body language, Press and Skill.

Discussion: The essay shows that the psychotherapist experience and describethe ISTDP method as a way to jointly with the patient create, a strong consciousand unconscious therapeutic alliance and a healing relationship. The result wassimilar in all respondents and consistent with theory and previous research.Possible future studies are suggested.

Symptoms after inflammatory activation, so-called sickness behaviour, overlap with trans-diagnostic complaints. As no self-report questionnaire to assess sickness behaviour exists, we aimed to develop such an instrument, the Sickness Questionnaire. Items responsive to experimentally induced inflammatory activation (randomized double-blind study endotoxin (0.6 ng/kg) versus placebo, n = 52) were selected and the statistical properties were examined in 172 primary care patients. A principal component analysis indicated a one-factor solution (Cronbach's alpha = .86). This 10-item scale correlated with depression ( β = .41, p < .001), anxiety ( β = .36, p < .001), self-rated health ( β = .28, p < .001) and a single item of feeling sick ( β = .55, p < .001). The results support the adequacy of Sickness Questionnaire as a brief assessment instrument of perceived sickness behaviour.

Parents of children with autism spectrum disorder (ASD) face many challenges which lead to low levels of psychological well-being, partly caused by inability to parent in accordance with one’s values. Child-directed play, a moment of being fully attentive and responsive to one’s child, has the potential to increase parental values. A non-concurrent multiple-baseline experimental design investigated whether daily exercises of child-directed play improved valued parenting and parental perspective-taking. Eight parents of children with diagnosed or suspected ASD were followed daily for six weeks. The intervention comprehended daily practice of child-directed play and video supervision. Child-directed play increased ratings of parental values for all but one participant (Hedges’ g* = 1.67) with effect maintained at follow-up, and increased ratings of parental perspective-taking. A gradual effect indicates the need for greater difference in baseline length between participants. No effects on children, nor on parental well-being were investigated in the present study.

Objectives: To evaluate the effectiveness of relapse prevention (RP) as a treatment for internet gaming disorder (IGD).

Design: Randomized controlled trial.

Setting: Three child and adolescent psychiatry (CAP) units in Region Skåne, Sweden.

Participants: Children aged 13-18 years, coming for their first visit to CAP during 2022, were screened for gaming behavior. Those who met the proposed DSM-5 criteria for IGD were offered participation in the trial, if they had the capacity to provide written informed consent and if they spoke Swedish. A total of 111 CAP patients agreed to participate. Out of those, 11 patients were excluded due to incorrect inclusion such as young age (n = 1), or due to the absence of responses to follow-up measures (n = 9). After exclusion, 102 participants remained (intervention = 47, control = 55).

Interventions: The intervention, RP, is based on cognitive behavioral treatment (CBT) and was provided individually, comprising of five to seven 45-min sessions over a period of 5 to 7 weeks versus treatment as usual.

Outcome measures: Participants were assessed with Game Addiction Scale for Adolescents pre-treatment (GASA) (baseline), post-treatment (treatment group only), and 3 months after baseline (follow-up).

Results: The repeated measures ANOVA showed a significant interaction effect between treatment and time. Both the control group and treatment group lowered their mean GASA score from baseline to follow-up significantly, but the improvement was greater in the treatment group (mean difference in control group -5.1, p < 0.001, 95% CI = - 3.390 to -6.755, mean difference in treatment group -9.9, p < 0.001, 95% CI = -11.746 to -8.105).

Conclusion: RP was found to be superior to treatment as usual in terms of reduction of IGD symptoms. Future research should address which aspects within a given treatment are effective, who benefits from treatment, in what aspects, and why.

Although the Flynn Effect has been studied widely across cultural, geographic, and intellectual domains, and many explanatory theories have been proposed, little past research attention has been paid to subgroup differences. Rodgers and Wänström (2007) identified an aggregate-level Flynn Effect (FE) at each age between 5 and 13 in the Children of the National Longitudinal Survey of Youth (NLSYC) PIAT-Math data. FE patterns were not obtained for Reading Recognition, Reading Comprehension, or Digit Span, consistent with past FE research suggesting a closer relationship to fluid intelligence measures of problem solving and analytic reasoning than to crystallized measures of verbal comprehension and memory. These prior findings suggest that the NLSYC data can be used as a natural laboratory to study more subtle FE patterns within various demographic subgroups. We test for subgroup Flynn Effect differences by gender, race/ethnicity, maternal education, household income, and urbanization. No subgroups differences emerged for three demographic categories. However, children with more educated (especially college educated) mothers and/or children born into higher income households had an accelerated Flynn Effect in their PIAT-M scores compared to cohort peers with lower educated mothers or lower income households. We interpret both the positive and the null findings in relation to previous theoretical explanations.

Purpose – The cost of selecting and training new police officers is high. However, previous researchhas provided limited guidance on how to select the best applicants. The purpose of this paper is toenhance the understanding of the possibilities to select suitable applicants by using combinations offour common categories of selection methods, namely cognitive tests, personality inventories, physicaltests, and rater-based methods (i.e. interviews).

Design/methodology/approach – Using a sample of Swedish police recruits (n¼750) the authorsperformed hierarchical multiple regression analyses, predicting four criteria – performance, satisfaction,retention, and health – at three consecutive time points (after two years of academy training, after sixmonths of field training, and after the first work year).

Findings – No group of selection methods consistently predicted all four criteria at the three timepoints. In most analyses more than one class of selection methods were statistically significant, but thefindings did not support the use of rater-based methods.

Practical implications – Instead of the common praxis of using interviews, the findings suggest analternative praxis. This involves using the remaining information from cognitive tests, personalityinventories, and general fitness tests that had been used in earlier hurdles to screen out unsuitable applicants.

Originality/value – The study extends previous research by including several follow-ups, showingthe value of combining different selection methods, and using alternative criteria of successful policerecruitment (i.e. satisfaction, retention, and health).

Denna studie undersöker vilka faktorer som bidrar till att yngre poliser i Sverige väljer att lämna yrket. Studien följer en kohort (N=717) av yngre poliser. Data från antagningen till polisutbildningen (T1-2008), efter ett års arbete (T2-2011) och efter sju års arbete (T3-2017) används för statistiska analyser baserade på en bred uppsättning variabler. Resultaten visar att förhållandevis få poliser lämnat yrket (7,4%) och att det finns få skillnader mellan de som stannat respektive lämnat yrket. Låg organisationssamhörighet efter ett års arbete var den enskilt starkaste prediktorn av frivillig uppsägning. Åtgärder som stärker organisationssamhörigheten tidigt i karriären bör därför prioriteras.

 Abstract 

Individual psychological factors have been recognized to play an important role in the development of stress-related symptomatology. Despite extensive comorbidity between stress-related ill health and mood disorders, the advances in research on emotion regulation and transdiagnostics, have not been recognized in stress research to any considerable degree. In the current study, using a single subject design with multiple baselines across individuals (n=6), a transdiagnostic treatment intervention targeting maladaptive emotional regulation strategies was implemented on patients suffering from stress-related symptomatology. Results show that symptoms of exhaustion decreased in five of six participants on post-measures, with considerable convergence between measures of depression, anxiety and stress. Further investigation of treatment effects, alongside the processes linking emotion regulation and stress-related symptomatology are needed. 

Objective: Primary care staff faces a complex work environment including a heavy administrative work load and perceive some work tasks as illegitimate. This study aimed to elucidate associations between the perceived legitimacy of work tasks, the psychosocial work environment, and the utilization of work time among Swedish primary care staff.

Design and setting: The study was designed as a multicenter study involving all staff categories, i.e. registered nurses, primary care physicians, care administrators, nurse assistants and allied professionals, at eleven primary care centers in Sweden.

Subjects: Participants completed the Bern Illegitimate Tasks Scale and the Copenhagen Psychosocial Questionnaire. They also recorded time spent on all work tasks, day by day during two separate weeks.

Main outcome measures and results: More than a quarter (27%) of primary care physicians perceived a high proportion of unnecessary work tasks. After adjusting for profession, age and gender, the perception of having to perform unreasonable work tasks was positively associated with experiencing role conflicts and with the proportion of organization-related administration and service work tasks.

Conclusion: Across all staff groups, the perception of unreasonable work tasks was more pronounced among staff with a high proportion of non-patient related administration. Also, the perception of having to perform a large amount of illegitimate work tasks affected the psychosocial work environment negatively, which might influence staffs perception of their professional roles. These results illuminate the importance of decision makers to thoroughly consider the distribution and allocation of non-patient related work tasks among staff in primary care.Key pointsWe observed an interaction between perception of having a large proportion of illegitimate work tasks and impaired psychosocial work environment. • More than a quarter of the primary care physicians perceived a high proportion of unnecessary work tasks.• Across all staff groups, performing unreasonable work tasks was associated with an experience of having role conflicts.• Across all staff groups, a perception of performing unreasonable work tasks was associated with the proportion of non-patient related administrative work tasks.

According to the literature, landscape (panoramas, heritage objects e.g. landmarks) affects people in various ways. Data are primarily developed by asking people (interviews, photo sessions, focus groups) about their preferences, but to a lesser degree by measuring how the body reacts to such objects. Personal experience while driving a car through a landscape is even more rare.

In this paper we study how different types of objects in the landscape affect drivers during their drive. A high-fidelity moving-base driving simulator was used to measure choice of speed and lateral position in combination with stress (heart rate measure) and eye tracking. The data were supplemented with questionnaires. Eighteen test drivers (8 men and 10 women) with a mean age of 37 were recruited. The test drivers were exposed to different new and old types of landscape objects such as 19th century church, wind turbine, 17th century milestone and bus stop, placed at different distances from the road driven.

The findings are in some respect contradictory, but it was concluded that that 33% of the test drivers felt stressed during the drive. All test drivers said that they had felt calm at times during the drive but the reason for this was only to a minor degree connected with old and modern objects. The open landscape was experienced as conducive to acceleration. No significant differences could be observed concerning the test drivers' gaze between old or modern objects, but a significant difference was observed between the test drivers' gaze between road stretches with faraway objects and stretches without objects.

Animal vehicle collisions (AVC's) have large economic, medical and ecological consequences but have rarely been studied with respect to driver behaviour. The aim of this study was to investigate different AVC-relevant landscape settings (vegetation cover), with and without game fencing and in combination with encountering moose. Twenty-five participants took part in an advanced driving simulator experiment. The results show that neither the presence of a game fence nor vegetation was found to affect driving speed, speed variability, lateral position or visual scanning in general. When a moose appeared at the side of the road, the drivers reacted by slowing down earlier and reducing their speed more when no game fence was present. Furthermore, the speed reduction when a moose was present was significantly larger when the vegetation was sparse. Game fencing made drivers feel at ease whereas dense vegetation was experienced as more stressful.

Animal vehicle collisions (AVC's) have large economic, medical and ecological consequences but have rarely been studied with respect to driver behaviour. The aim of this study was to investigate different AVC-relevant landscape settings (vegetation cover), with and without game fencing and in combination with encountering moose. Twenty-five participants took part in an advanced driving simulator experiment. The results show that neither the presence of a game fence nor vegetation was found to affect driving speed, speed variability, lateral position or visual scanning in general. When a moose appeared at the side of the road, the drivers reacted by slowing down earlier and reducing their speed more when no game fence was present. Furthermore, the speed reduction when a moose was present was significantly larger when the vegetation was sparse. Game fencing made drivers feel at ease whereas dense vegetation was experienced as more stressful.

Animal vehicle collisions (AVC's) have large economic, medical and ecological consequences but have rarely been studied with respect to driver behaviour. The aim of this study was to investigate different AVC-relevant landscape settings (vegetation cover), with and without game fencing and in combination with encountering moose. Twenty-five participants took part in an advanced driving simulator experiment. The results show that neither the presence of a game fence nor vegetation was found to affect driving speed, speed variability, lateral position or visual scanning in general. When a moose appeared at the side of the road, the drivers reacted by slowing down earlier and reducing their speed more when no game fence was present. Furthermore, the speed reduction when a moose was present was significantly larger when the vegetation was sparse. Game fencing made drivers feel at ease whereas dense vegetation was experienced as more stressful.

Driver sleepiness is one common reason for road crashes. The exact number of crashes is difficult to say. The aim of the present study is to identify criteria and protocols to use in field in order to learn more about driver sleepiness involvement in road crashes. The study has been done in collaboration with the police in Umeå. The police in Linköping and Gothenburg have also contributed during the development of the protocols. The study has three phases: review of earlier studies and experience from other countries, development of a protocol based on the most relevant criteria and finally a pilot test using the protocols at field directly at the road crashes. The result shows that attempts have been done all over the world. However, very few studies have been published or documented in scientific journals. It is more a question of practical experience at best having been documented in technical reports. The most used protocols are based on the work done by the Canadian police. They use two types of checklists; one at road directly at the crash site, one at the office in case the first analysis indicates suspicions that sleepiness has been involved. In the present study the protocol used directly at the crash site was used. The results show that the questions involved in the protocol were easily addressed to the involved drivers. The field study shows problems to motivate the police officers to take their time to use the protocol in field. The reason for this is unknown. One reason could be that this new routine needs time to be settled. The motivation among the police officers was seen to increase during the project. One explanation given was that they were more and more aware of the problem with sleepiness, thanks to the protocols. This will most truly make them more motivated over time.

Sömniga förare är en viktig orsak till trafikolyckor. Syftet med denna avhandling är att förmedla ny kunskap om sömnighet och risken för olyckor på vägarna genom att undersöka försämrad körförmåga kopplad till sömnighet hos förare. Motmedel kommer också att lyftas fram. Avhandlingen börjar med ett avsnitt om dödsfall och skador som ett folkhälsoproblem och hur sömnighet hos förare inverkar på trafikolyckor. Därefter följer att avsnitt som beskriver sömn, trötthet och grundläggande reglering av sömn och uppvaknande. Nästa avsnitt handlar om sömnighetsrelaterade trafikolyckors orsaker och kännetecken. Avslutningsvis diskuteras några motmedel mot sömnighet.

Objective It is generally believed that professional drivers can manage quite severe fatigue before routine driving performance is affected. In addition, there are results indicating that professional drivers can adapt to prolonged night shifts and may be able to learn to drive without decreased performance under high levels of sleepiness. However, very little research has been conducted to compare professionals and non-professionals when controlling for time driven and time of day.

Method The aim of this study was to use a driving simulator to investigate whether professional drivers are more resistant to sleep deprivation than non-professional drivers. Differences in the development of sleepiness (self-reported, physiological and behavioral) during driving was investigated in 11 young professional and 15 non-professional drivers.

Results Professional drivers self-reported significantly lower sleepiness while driving a simulator than nonprofessional drivers. In contradiction, they showed longer blink durations and more line crossings, both of which are indicators of sleepiness. They also drove faster. The reason for the discrepancy in the relation between the different sleepiness indicators for the two groups could be due to more experience to sleepiness among the professional drivers or possibly to the faster speed, which might unconsciously have been used by the professionals to try to counteract sleepiness.

Conclusion Professional drivers self-reported significantly lower sleepiness while driving a simulator than non-professional drivers. However, they showed longer blink durations and more line crossings, both of which are indicators of sleepiness, and they drove faster.

Introduction: There is a common understanding that driving under the influence of alcohol is associated with higher risk of being involved in crashes with injuries and possible fatalities as the outcome. Various countermeasures have therefore from time to time been taken by the authorities to prevent drunk driving. One of them has been the alcohol interlock. Up to now, interlocks have mainly been used by previously convicted drunk drivers and in the commercial road transport sector, but not in private cars.

Objective and Method: New technology has today reached a level where broader implementation might be possible. To our knowledge, however, little is known about different stakeholders' opinions of a broader implementation of such systems. In order to increase that knowledge, we conducted a focus group study to collect in-depth thoughts from different stakeholders on this topic. Eight focus groups representing a broad societal span were recruited and conducted for the purpose.

Results and Conclusions: The results show that most stakeholders thought that an integrated system for alcohol detection in vehicles might be beneficial in lowering the number of drunk driving crashes. They said that the system would probably mainly prevent driving by people who unintentionally and unknowingly drive under the influence of alcohol. The groups did, however, not regard the system as a final solution to the drunk driving problem, and believed that certain groups, such as criminals and alcoholics, would most likely find a way around the system.

Concerns were raised about the risk of increased sleepy driving and driving just under the legal blood alcohol concentration (BAC) limit. The results also indicate that stakeholders preferred a system that provides information on the BAC up to the legal limit, but not for levels above the limit; for those, the system should simply prevent the car from starting. Acceptance of the system depended on the reliability of the system, on its ability to perform fast sampling, and on the analytical process, as well as the system's more or less inconspicuous placement and user-friendliness. The stakeholders thought that drivers would probably not voluntarily demand the system. So if broad implementation was desired, it would have to be made compulsory by legislation. As an incentive to increase demand, lower taxes and insurance premiums were suggested.

In connection with boarding and alighting bus passengers are exposed to risks caused by other traffic. Children are especially vulnerable when traveling to and from school, and there are strong reasons for urging the vehicles passing a stationary school transport to reduce their speed significantly. Based on the experience of a previous project it was decided to propose the imposition of a limit of 30 km/h when there is a stationary school transport throughout the country on roads with speed limits of 70 km/h and less. In connection with a change of the traffic regulations it is important to create a school bus sign that is respected by all road users. The purpose of this study is to develop and test a school bus sign that has a high degree of conspicuity, and can be detected and read from an adequate distance. Most important, it has to be understood and respected. The study results will provide a basis for a set of requirements on a sign that should make drivers reduce their speed to 30 km/h when passing a stationary school bus. The study includes both workshops and focus groups with various stakeholders, one indoor and one outdoor lab experiment, and a field test. The results from the sub-studies lead to a recommendation to use a VMS-type sign that includes motion, which is more conspicuous than signs with a static symbol. It is expected that the final version of a digital sign will have a similar or better conspicuity and legibility than the traditional bus sign, which should increase compliance. Furthermore, it is likely that compliance with the new speed regulation will be improved when drivers not only are informed about the potential hazard source - children - but when they, too, are informed about the appropriate action - a speed reduction to 30 km/h.

Introduction: The overall aim of this study is to compare day-time driving with night-time driving looking at line crossings during self-reported sleepiness and long blinks. The hypothesis is that high levels of self-reported sleepiness (KSS 9) and long blink duration (>0.15 s) will be less associated with critical events during the day-time compared to night-time.

Method: The study is based on data from a driving simulator experiment with 16 participants driving 150 km on a typical Swedish motorway scenario twice: once during daytime and once during night time. In total data from 6 segments of 4 km each equally distributed along the drive was averaged and included in the analysis. A Mixed Model Anova was used to test the effects on KSS, Blink Duration and Line Crossings with factors for Session (Day/Night) and Road segment (1–6), and participant as random. In addition, a logistic regression was used to identify when there is a risk for line crossings. Finally, the proportion of line crossings in relation to high KSS values and long blink durations was tested with Fisher’s exact test.

Results: The results show no differences in the percentage of Line Crossings to the left during high levels of Karolinska Sleepiness Scale during daytime (33%) compare to night-time (40%). However, there was a significant difference between day and night time line crossings while the driver had long duration blinks (4% during daytime and 35% during night-time). Despite these results the most promising predictor of line crossings in each segment of 4 km/h was KSS with an Odds Ratio of 5.4 with a reference value at Karolinska Sleepiness Scale level 5.

Conclusion: In conclusion, the results do not support the hypothesis that high levels of KSS will result in more frequent line crossings at night time compared to day time. However, the result supports the hypothesis that long blink durations are associated with more line crossings when they appear during night time than during daytime. © 2017, The Author(s).

Introduction The overall aim of this study is to compare daytime driving with night-time driving looking at line crossings during self-reported sleepiness and long blinks. The hypothesis is that high levels of self-reported sleepiness (KSS 9) and long blink duration (amp;gt;0.15 s) will be less associated with critical events during the day-time compared to night-time. Method The study is based on data from a driving simulator experiment with 16 participants driving 150 km on a typical Swedish motorway scenario twice: once during daytime and once during night time. In total data from 6 segments of 4 km each equally distributed along the drive was averaged and included in the analysis. A Mixed Model Anova was used to test the effects on KSS, Blink Duration and Line Crossings with factors for Session (Day/Night) and Road segment (1-6), and participant as random. In addition, a logistic regression was used to identify when there is a risk for line crossings. Finally, the proportion of line crossings in relation to high KSS values and long blink durations was tested with Fishers exact test. Results The results show no differences in the percentage of Line Crossings to the left during high levels of Karolinska Sleepiness Scale during daytime (33%) compare to night-time (40%). However, there was a significant difference between day and night time line crossings while the driver had long duration blinks (4% during daytime and 35% during night-time). Despite these results the most promising predictor of line crossings in each segment of 4 km/h was KSS with an Odds Ratio of 5.4 with a reference value at Karolinska Sleepiness Scale level 5. Conclusion In conclusion, the results do not support the hypothesis that high levels of KSS will result in more frequent line crossings at night time compared to day time. However, the result supports the hypothesis that long blink durations are associated with more line crossings when they appear during night time than during daytime.

The aim of the present study was to explore if observer rated sleepiness (ORS) is a feasible method for quantification of driver sleepiness in field studies. Two measures of ORS were used:

1. one for behavioural signs based on facial expression, body gestures and body movements labelled B-ORS, and
2. one based on driving performance e.g. if swerving and other indicators of impaired driving occurs, labelled D-ORS

A limited number of observers sitting in the back of an experimental vehicle on a motorway about 2 hours repeatedly 3 times per day (before lunch, after lunch, at night) observed 24 participant's sleepiness level with help of the two observer scales. At the same time the participant reported subjective sleepiness (KSS), EOG was recorded (for calculation of blink duration) and several driving measure were taken and synchronized with the reporting.

Based on mixed model Anova and correlation analysis the result showed that observer ratings of sleepiness based on drivers' impaired performance and behavioural signs are sensitive to extend the general pattern of time awake, circadian phase and time of driving. The detailed analysis of the subjective sleepiness and ORS showed weak correspondence on an individual level. Only 16% of the changes in KSS were predicted by the observer. The correlation between the observer ratings based on performance (D-ORS) and behavioural signs (B-ORS) are high (r =. 588), and the B-ORS shows a moderately strong association (r =. 360) with blink duration. Both ORS measures show an association (r>0.45) with KSS, whereas the association with driving performance is weak.

The results show that the ORS-method detects the expected general variations in sleepy driving in field studies, however, sudden changes in driver sleepiness on a detailed level as 5 minutes is usually not detected; this holds true both when taking into account driving behaviour or driver behavioural signs.

The aim of the present study was to explore if observer rated sleepiness (ORS) is a feasible method for quantification of driver sleepiness in field studies. Two measures of ORS were used: (1) one for behavioural signs based on facial expression, body gestures and body movements labelled B-ORS, and (2) one based on driving performance e.g. if swerving and other indicators of impaired driving occurs, labelled D-ORS. A limited number of observers sitting in the back of an experimental vehicle on a motorway about 2 hours repeatedly 3 times per day (before lunch, after lunch, at night) observed 24 participant's sleepiness level with help of the two observer scales. At the same time the participant reported subjective sleepiness (KSS), EOG was recorded (for calculation of blink duration) and several driving measure were taken and synchronized with the reporting. Based on mixed model Anova and correlation analysis the result showed that observer ratings of sleepiness based on drivers' impaired performance and behavioural signs are sensitive to extend the general pattern of time awake, circadian phase and time of driving. The detailed analysis of the subjective sleepiness and ORS showed weak correspondence on an individual level. Only 16% of the changes in KSS were predicted by the observer. The correlation between the observer ratings based on performance (D-ORS) and behavioural signs (B-ORS) are high (r = .588), and the B-ORS shows a moderately strong association (r = .360) with blink duration. Both ORS measures show an association (r>0.45) with KSS, whereas the association with driving performance is weak. The results show that the ORS-method detects the expected general variations in sleepy driving in field studies, however, sudden changes in driver sleepiness on a detailed level as 5 minutes is usually not detected; this holds true both when taking into account driving behaviour or driver behavioural signs.

Bus drivers often work irregular hours or split shifts and their work involves high levels of stress. These factors can lead to severe sleepiness and dangerous driving. This study examined how split shift working affects sleepiness and performance during afternoon driving. An experiment was conducted on a real road with a specially equipped regular bus driven by professional bus drivers. The study had a within-subject design and involved 18 professional bus drivers (9 males and 9 females) who drove on two afternoons; one on a day in which they had driven early in the morning (split shift situation) and one on a day when they had been off duty until the test (afternoon shift situation). The hypothesis tested was that split shifts contribute to sleepiness during afternoon, which can increase the safety risks. The overall results supported this hypothesis. In total, five of the 18 drivers reached levels of severe sleepiness (Karolinska Sleepiness Scale 8) with an average increase in KSS of 1.94 when driving in the afternoon after working a morning shift compared with being off duty in the morning. This increase corresponded to differences observed between shift workers starting and ending a night shift. The Psychomotor Vigilance Task showed significantly increased response time with split shift working (afternoon: 0.337 s; split shift 0.347 s), as did the EEG-based Karolinska Drowsiness Score mean/max. Blink duration also increased, although the difference was not significant. One driver fell asleep during the drive. In addition, 12 of the 18 bus drivers reported that in their daily work they have to fight to stay awake while driving at least 2-4 times per month. While there were strong individual differences, the study clearly showed that shift working bus drivers struggle to stay awake and thus countermeasures are needed in order to guarantee safe driving with split shift schedules.

Bus drivers often work irregular hours or split shifts and their work involves high levels of stress. These factors can lead to severe sleepiness and dangerous driving. This study examined how split shift working affects sleepiness and performance during afternoon driving. An experiment was conducted on a real road with a specially equipped regular bus driven by professional bus drivers.

The study had a within-subject design and involved 18 professional bus drivers (9 males and 9 females) who drove on two afternoons; one on a day in which they had driven early in the morning (split shift situation) and one on a day when they had been off duty until the test (afternoon shift situation). The hypothesis tested was that split shifts contribute to sleepiness during afternoon, which can increase the safety risks. The overall results supported this hypothesis. In total, five of the 18 drivers reached levels of severe sleepiness (Karolinska Sleepiness Scale ≥8) with an average increase in KSS of 1.94 when driving in the afternoon after working a morning shift compared with being off duty in the morning. This increase corresponded to differences observed between shift workers starting and ending a night shift. The Psychomotor Vigilance Task showed significantly increased response time with split shift working (afternoon: 0.337. s; split shift 0.347. s), as did the EEG-based Karolinska Drowsiness Score mean/max. Blink duration also increased, although the difference was not significant. One driver fell asleep during the drive. In addition, 12 of the 18 bus drivers reported that in their daily work they have to fight to stay awake while driving at least 2-4 times per month. While there were strong individual differences, the study clearly showed that shift-working bus drivers struggle to stay awake and thus countermeasures are needed in order to guarantee safe driving with split shift schedules.

The overall aim with this study was to gather knowledge about countermeasures for driver fatigue (including sleepiness) in road, rail, sea and air transportation. The knowledge has been used as an input for evaluating advantages and disadvantages with different countermeasures and to estimate their potential to be used regardless mode of transportation. The method used was a literature review and a workshop with experts from all transportation modes. At the workshop the effectiveness of countermeasures for a single mode, but also regardless mode were discussed and a ranking was done. The report discuss the potential of fighting fatigue among drivers for specific mode of transport but also from a more generic point of view, considering scheduling, model prediction of fatigue risk, legislation, a just culture, technical solutions, infrastructure, education, self-administered alertness interventions and fatigue risk management (FRM). The overall judgement was that a just culture, education, possibility to nap and schedules taking the humans limitations into consideration as the most effective countermeasures to fight fatigue, regardless mode of transportation.

Travelling by bus is one of the safest modes of transport. However, crashes still happen and studies have found that the most severe crashes are related to rollovers, mainly on rural roads. The most severe injuries occur when unbuckled passengers are thrown out through the windows or get stuck under the bus. In Sweden the use of a seat belt and information about seat belt use when traveling by bus is regulated in Traffic Ordinance (1998: 1276) Chapter 4 §10a. In short, all bus passengers three years or older should be seated in a place with a seat belt, if there is such a place, and should use the belt. If there is no seat belt available, it is allowed to stand in the bus (if the bus is approved for standing places). The legal responsibility to inform and make sure passengers under 15 use the belt are on the bus driver. Despite existing regulations there is no clear view on the usage rate of seat belt in buses, or on the travellers’ view of their own usage and the reasons to not buckle up. This study aims to evaluate seat belt usage in buses and to understand travellers’ incentives of seatbelt usage.

This study aims to evaluate seat belt usage in buses and to understand travellers' incentives of seat belt usage. Methods used are observational studies (10 cities, with 328 bus observations), focus group discussion (7 groups with a total of 32 participants) and a web survey (n = 1737 respondents). The results show that the seat belt use among bus passengers can be improved especially in regional and commercial bus traffic. It is more common to buckle up on long trips than on short trips. However, even though observations show high usage during long trips, travellers report that they remove the seat belt after a while if they want to sleep or for comfort reasons. For the bus drivers it is not possible to control passengers' usage. Dirty seat belts and technical malfunction might deter some passengers from using them and therefore systematic cleaning and control of seats and belts are recommended. On short trips one reason for not using the belt is related to worries about getting stuck and not being ready to get off in time. In general, it is most important to increase the usage on high-speed roads (>60 km/ h), in lower speed it might be more important to provide a seat for each passenger. Based on the results a list of recommendations is presented.

BACKGROUND: Approximately 30% of Swedish urban bus drivers report having been exposed to threats or violence. As 50% of drivers have voiced concerns about the occurrences, threats and violence also represent contributing factors to driver stress and fatigue. OBJECTIVE: The aim of this study was to explore bus drivers' experience of threats and violence; how threats and violence manifests and how the problem is handled by drivers. Gaining understanding of the circumstances is important to reduce the number of threats and violent incidents to provide healthy and attractive working conditions for drivers. METHODS: This study is based on in-depth interviews with 12 urban bus drivers in the City of Malmö in Sweden. RESULTS: Urban bus drivers experience threats daily from passengers, although physical violence occurs less often. The most common situations resulting in threats involve asking passengers to show valid tickets, denying child carriages onboard and running late to a bus stop. The drivers have not received clear guidelines as to strategic handling of the invalid ticket situation. CONCLUSIONS: Recommendations include a clear policy and consensus with regard to handling invalid tickets, providing drivers with guidelines for appropriate procedures for passengers refusing to pay, improving reporting routines and establishing a strategy for the Public Transportation provider and operator to follow with regard to reports, in-vehicle surveillance cameras including informing passengers that they are being video recorded as well as harmonizing the location of alarm buttons on buses. 

Driver fatigue has received increased attention during recent years and is now considered to be a major contributor to approximately 15-30% of all crashes. However, little is known about fatigue in city bus drivers. It is hypothesized that city bus drivers suffer from sleepiness, which is due to a combination of working conditions, lack of health and reduced sleep quantity and quality.

The overall aim with the current study is to investigate if severe driver sleepiness, as indicated by subjective reports of having to fight sleep while driving, is a problem for city based bus drivers in Sweden and if so, to identify the determinants related to working conditions, health and sleep which contribute towards this. The results indicate that driver sleepiness is a problem for city bus drivers, with 19% having to fight to stay awake while driving the bus 2-3 times each week or more and nearly half experiencing this at least 2-4 times per month. In conclusion, severe sleepiness, as indicated by having to fight sleep during driving, was common among the city bus drivers. Severe sleepiness correlated with fatigue related safety risks, such as near crashes.

Bus drivers often have irregular working hours and their work involve high levels of stress. These factors can lead to severe fatigue and the purpose of this study is to highlight how the working hours affect sleep, stress, fatigue and driving performance. The project includes four studies: questionnaire, sleep diaries and actigraphy, analyze of rosters and an experiment on real road with bus drivers. The hypotheses were that early morning shift, split shifts, long working hours and short hours of rest between shifts contribute to sleepiness, stress, fatigue and impaired driving performance, which together can result in increased safety. The overall results support these hypotheses. Generally, sleepiness and fatigue while driving are perceived as problems because drivers connect those factors with impaired driving performance, which increases the risk of incidents and accidents. In total 45 percent of all drivers had trouble at least twice a month to stay awake while driving and 19 percent had over the past decade been involved in an incident due fatigue. The experiment with split shift driving support these findings. The report concludes with a list of suggestions.

The aims with the study have been to improve the knowledge about where fatigue related accidents occur but also to generate hypotheses about what causes drivers to experience fatigue. The focus has been on hypotheses about what information a driver needs to:

• recognise the feeling of being fatigued

• stop driving when fatigued

• Improve the understanding of the danger of driving when fatigued

The study includes both an accident analysis and discussion within focus groups. Three discussions have been performed: one with long distance commuters, one with young drivers and one with professional drivers. The knowledge received and hypotheses developed from this work has resulted in a questionnaire. The aim with the questionnaire is to test if it is possible to generalise the hypothesis. The questionnaire has been tested within the project.

The aim of the EU project IN-SAFETY is to create effective combinations of traditional infrastructure measures combined with new technology to increase the self-explanatory and forgiving nature of the road traffic system. This report describes the method, results and conclusions of a driving simulator experiment with the aim to evaluate the effect of two scenarios of importance selected on a theoretical framework within IN-SAFETY: lane departure warning in terms of milled rumble strips or as a driver support system, and the effect of an in-vehicle warning system informing there is a school bus ahead, simulating a system based on vehicle to vehicle information. Concerning the "lane departure warning", the experiment considered possibilities and consequences of replacing the infrastructure element milled rumble strips with a haptic in-vehicle system. Both centre and side line rumble strips on a two-lane highway were studied and compared with a baseline. In-vehicle "School bus ahead warning" was considered as an example of in-vehicle information used to inform the driver of upcoming events. Both rumble strips and school bus warning was studied for drivers after not having slept the night before driving as well as after a night's sleep in order to investigate consequences of driver state on system effectiveness. The results showed that there is a potential to substitute the infrastructure measure rumble strips with an in-vehicle assistance system. Moreover, in-vehicle information was found to be an effective way of reducing the subjects' speeds during temporary critical situations concerning traffic safety.

The aim of this moving base driving simulator study with 19 drivers participating in a random order day and night time, was to evaluate the effect of low-frequency road noise on driver sleepiness and performance, including both long-term and short-term effects.

It is a well-known fact today that driver sleepiness is a contributory factor in crashes. Factors considered as sleepiness contributor are mostly related to time of the day, hours being awake and hours slept. Factors contributing to active and passive fatigue are mostly focusing on the level of cognitive load. Less is known what role external factors, e.g. type of road, sound/noise, vibrations etc., have on the ability to stay awake both under conditions of sleepiness and under active or passive fatigue.

The results support to some extent the hypothesis that road-induced interior vehicle sound affects driving performance and driver sleepiness. Increased low-frequency noise helps to reduce speed during both day- and night time driving, but also contributes to increase the number of lane crossings during night time.