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| 2. |
- Fredriksson, Henrik, et al.
(author)
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Förstudie – Datadriven analys av restider
- 2022
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Reports (other academic/artistic)abstract
- Det uppkopplade samhället möjliggör kontinuerlig insamling av trafikdata genom de moderna fordonens navigationssystem, så väl som genom mobiltelefoner och andra GPS-enheter. Den ökade tillgången till trafikdata ger möjligheter analysera att trafiksystemet ur flera olika perspektiv. En typ av trafikdata som kan extraheras ur GPS-data är fordonshastigheter. Genom att analysera hur fordonshastigheter förändras över tid och identifiera avvikelser från ett normaltillstånd så skulle det vara möjligt att upptäcka och förutsäga potentiella brister i trafiksystemet. Många gånger upptäcks brister i infrastrukturen i ett relativt sent skede vilket i sin tur kan innebära både omfattande och kostsamma åtgärder för att komma till rätta med problemen.Syftet med förstudien har varit att utveckla och utvärdera metoder och modeller för att detektera brister och identifiera hastigheter som relativt avviker från normaltillståndet, dvs ett fokus på fordonshastigheter som framför allt är ovanligt låga. Utgångspunkten har också varit att finna lämplig metod för att modellera trafiksituationen med hjälp av uppmätta fordonshastigheter. Det vill säga metoder som syftar till att ur ett övergripande perspektiv beskriva normaltillståndet längs med de studerade vägsträckorna. Analyser av normaltillståndets förändring över tid öppnar upp möjligheten att detektera om brister relaterat till vägsträckors kapacitet och framkomlighet uppstått eller avgöra om normaltillståndet på en vägsträcka är stabilt eller förändras över tid.Det är framför allt de relativt låga fordonshastigheterna som uppstår som blir en indikator på att en vägsträcka har brister. Därför föreslås en metod för att systematiskt identifiera och gruppera uppmätta fordonshastigheter i låga, normala och höga hastigheter. En utgångspunkt har varit robusthet och att möjliggöra jämförelser av hastigheter för olika vägsträckor med olika attribut som antal körfält och skyltad hastighet med varandra. Vi presenterar även ett nytt mått som beskriver hur gruppen med relativt låga hastigheter förhåller sig till friflödeshastigheten som till exempel den skyltade hastigheten. Syftet med måttet är att kvantifiera framkomligheten på en vägsträcka eller vägsegment. Existerande mått och indikatorer baseras idag på fordonshastigheter som spänner från låga till höga hastigheter. Vi har i denna kontext tagit fram ett mått som endast tar hänsyn till vad som anses vara låga hastigheter och friflödeshastighet.Inom förstudien så har även en metod baserad på klusteranalys använts för de studerade vägsträckorna. Klusteranalys har i olika sammanhang visat sig effektivt för att kategorisera och detektera återkommande mönster i hastighetsprofiler. Syftet med klusteranalysen är att undersöka om det finns någon koppling mellan hastighetsprofiler som har liknande beteende och till exempel veckodag och tidpunkt. Genom klusteranalys skulle det vara möjligt att inte bara detektera vilka vägsträckor där det uppstår problem, utan det skulle även vara möjligt att prognostisera vid vilka veckodagar och tidpunkter där det finns risk att köer och andra problem kan uppstå.Förstudien är begränsad till användning av fordonhastigheter som datakälla och de framtagna metoderna och modellerna visar att det finns potential att frikoppla sig från andra datakällor som till exempel fordonsflöden för att detektera brister eller avvikelser som skulle kunna indikera brister i transportsystemet.
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| 3. |
- Holmgren, Anita, et al.
(author)
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High re-arrest rates among drug-impaired drivers despite zero-tolerance legislation
- 2008
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In: Accident Analysis and Prevention. - : Elsevier BV. - 0001-4575 .- 1879-2057. ; 40:2, s. 534-540
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Journal article (peer-reviewed)abstract
- Background: A zero-tolerance law for driving under the influence of drugs (DUID) in Sweden led to a 10-fold increase in the number of cases submitted by the police for toxicological analysis. The statutory blood-alcohol concentration (BAC) limit for driving is 0.2 mg/g (∼0.02 g%). Methods: An in-house database (TOXBASE) was used to investigate re-arrests for impaired driving over 4 years (2001-2004), which comprised 36,799 cases. The age, gender, re-arrest rate of the offenders and the concentrations of ethanol and amphetamine in blood samples were evaluated. Results: We found that 44% of individuals (N = 16,277) re-offended 3.2 times on average (range 1-23 arrests). Between 85 and 89% of first-time offenders were men and there was also a male dominance among the recidivists (88-93%). The mean age of drunken drivers was ∼40 years compared with ∼35 years for driving under the influence of amphetamine, which was the drug identified in 50-60% of DUID cases, either alone or together with other licit or illicit drugs. The median BAC was 1.5 mg/g (∼0.15 g%), which suggests a dominance of heavy drinkers. The median BAC was even higher in recidivists (1.6-1.7 mg/g). The median concentration of amphetamine in blood was 1.0 mg/L in recidivists compared with 0.5 mg/L in the first-time offenders. About 14% of drunken drivers re-offended 1-10 times compared with 68% of DUID suspects, who were re-arrested 1-23 times. People with only a scheduled prescription drug in blood were re-arrested much less frequently (∼17%) compared with those taking illicit drugs (68%). Conclusions: The appreciable increase in number of arrests for DUID after a zero-tolerance law might reflect a heightened enthusiasm by the police authorities armed with knowledge that a prosecution is easier to obtain. Zero-tolerance laws do not deter people from impaired driving judging by the high re-arrest rates. During the sentencing of hardcore offenders, the courts should give more consideration to the underlying substance abuse problem. © 2007 Elsevier Ltd. All rights reserved.
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| 4. |
- Holmgren, A, et al.
(author)
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Predominance of illicit drugs and poly-drug use among drug-impaired drivers in Sweden
- 2007
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In: Traffic Injury Prevention. - : Informa UK Limited. - 1538-9588 .- 1538-957X. ; 8:4, s. 361-367
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Journal article (peer-reviewed)abstract
- Objective. After Sweden's zero-tolerance law came into force (1 July 1999), the number of cases of driving under the influence of drugs (DUID) submitted by the police for toxicological analysis increased more than 10-fold. This prompted an in-depth investigation into the kinds of drugs used by DUID offenders, whether licit or illicit, and the frequency of their occurrence. Methods. All blood samples from DUID suspects sent by the police for toxicological analysis over a 4-year period (2001-2004) were investigated (N = 22,777 cases). Specimens of blood or urine were subjected to a broad screening analysis by immunoassay methods aimed at detecting amphetamines, cannabis, opiates, cocaine metabolite, and the major benzodiazepines. All positive results from the screening stage were verified by use of more specific analytical methods (e.g., GC-MS, LC-MS, GC-FID, and GC-NPD). Results. Between 80 and 85% of all the blood samples contained at least one banned substance and many contained two or more therapeutic and/or illicit drugs. About 15% of cases were negative for drugs, although these frequently (30-50%) contained ethanol above the legal limit for driving in Sweden, which is 0.20 mg/g (0.02 g%). Amphetamine was the most prominent illicit drug seen in 55-60% of cases either alone or together with other drugs of abuse. Stimulants like cocaine and/or its metabolite were infrequently encountered (1.2% of cases). The next most prevalent illicit drug was cannabis, with positive results for tetrahydrocannabinol (THC) in blood either alone (4%) or together with other psychoactive substances (20%). Morphine, codeine, and/or 6-acetyl morphine were identified in 2% of all DUID suspects, being indicative of heroin abuse. The major prescription drugs identified in blood were benzodiazepines (10%) as exemplified by diazepam, alprazolam, nitrazepam, and flunitrazepam. Drugs for treating insomnia, zolpidem and zopiclone, were also identified in blood samples from DUID suspects over the study period. Other therapeutic agents were encountered in only 1-2% of all cases. Conclusions. The dramatic increase in DUID after the zero-tolerance law came into force probably reflects enhanced police activity and more enthusiasm to apprehend and charge individuals for this offence. Illicit drugs, particularly amphetamine and cannabis, and poly-drug use were predominant compared with use of scheduled prescription drugs. The typical DUID offender in Sweden abuses central stimulants, particularly amphetamine, and has probably done so over many years. Options for treating offenders for their underlying substance abuse problem should be considered instead of the more conventional penalties for drug-impaired driving.
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| 5. |
- Holmgren, Anders, et al.
(author)
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Troponin T but not C-reactive protein is associated with future surgery for aortic stenosis : a population based nested case-referent study
- 2020
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In: Open heart. - : BMJ Publishing Group Ltd. - 2053-3624. ; 7:2
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Journal article (peer-reviewed)abstract
- Aims: High-sensitivity troponin T (hs-TnT) and high-sensitivity C reactive protein (hs-CRP) may convey prognostic information in patients with aortic stenosis (AS). This study evaluated if hs-TnT and hs-CRP associate with myocardial mass, and risk of future surgery for AS.Methods: In total, 336 patients (48% women) with surgery for AS with previous participation in large population surveys were identified. Preoperatively, myocardial mass and the presence of coronary artery disease (CAD) were assessed. Two matched referents were allocated for each case, and hs-TnT and hs-CRP were determined in stored plasma from the baseline survey. Conditional logistic regression analysis was used to estimate the risk (OR (95% CI)) related to one (natural logarithm) SD increase in hs-TnT and hs-CRP. Kaplan-Mayer and Cox regression analyses were used to evaluate time to surgery.Results: Median age (IQR) was 59.8 (10.3) years at survey, and median time between survey and surgery was 10.9 (9.3) years. Hs-TnT was independently associated with surgery for AS (1.24 (1.06–1.44)) irrespective of CAD, whereas Hs-CRP was not (1.05 (0.90–1.22)). Elevated hs-TnT levels at survey associated with shorter time to surgery (p<0.001), and with increased myocardial mass (p=0.002). Hs-CRP did not associate with time to surgery or with myocardial mass.Conclusions: Hs-TnT—but not hs-CRP—was associated with increased risk of—and shorter time to—future surgery for AS. Hs-TnT associated with myocardial mass at surgery which indicates that hs-TnT could be a potential biomarker for determining intervention.
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| 6. |
- Holmgren, Johan, et al.
(author)
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Modelling modal choice effects of regulation on low-sulphur marine fuels in Northern Europe
- 2014
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In: Transportation Research Part D: Transport and Environment. - : Elsevier BV. - 1361-9209 .- 1879-2340. ; 28, s. 62-73
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Journal article (peer-reviewed)abstract
- The implementation of MARPOL Annex VI in the North and Baltic Sea Sulphur Emission Control Area (SECA) has raised economic concerns among shippers and shipowners, as well as spurred policymakers to appeal to various interests, such as citizen health, export industry competitiveness, and consumer prices. To justify their cases, policymakers and stakeholders have commissioned various agencies to monitor the implementation’s effects upon sustainability, especially regarding a potential modal shift from sea to road transport. This article thus reviews some of these commissioned studies in order to analyse the effects of the implementation and the possibility of modal shift. It also provides an agent-based simulation study of route choice for comparatively high-value cargo from Lithuania in the east to the United Kingdom in the west. Ultimately, the results of our TAPAS study do not provide concrete evidence supporting a modal shift from sea to road transport and indeed, they indicate that a shift is unlikely to occur.
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| 7. |
- Holmgren, Per, et al.
(author)
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Alcohol and drugs in drivers fatally injured in traffic accidents in Sweden during the years 2000-2002
- 2005
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In: Forensic Science International. - : Elsevier BV. - 0379-0738 .- 1872-6283. ; 151:1, s. 11-17
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Journal article (peer-reviewed)abstract
- During the years 2000-2002, alcohol, pharmaceuticals and illicit drugs were analysed in blood samples from fatally injured drivers in Sweden. The total number of drivers was 920 and in 855 of these, corresponding to 93%, a toxicological investigation was performed. About 85% of the drivers were men and 15% were women. All but three women (96%) were car drivers while the corresponding figure for men was about 78% and about 13% were motorcyclists. The number of positive cases increased from 38.9% in year 2000 to 45.9% in year 2002 and alcohol was the most common drug with frequencies of 19.8%, 25.0% and 21.8% for the studied years 2000, 2001 and 2002, respectively. The median blood alcohol concentration ranged from 1.6 to 2.0 mg/mL for men and from 1.2 to 1.8 mg/mL for women. There was a decrease in cases where alcohol was the only drug detected, from 52 out of 58 cases (90%) in year 2000 to 41 out of 61 cases (67%) in 2002. At the same time there was an increase, from 5.4% to 10.0% of illicit drugs, mainly amphetamine, and the cases with multiple drug intake increased from 10% to 26%. The prevalence of pharmaceuticals as the only drug or drugs detected decreased from 14.0% to 10.4% and in the majority of these cases the drug concentrations were within the therapeutic range.
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| 8. |
- Holmgren, Per, et al.
(author)
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Stability of drugs in stored postmortem femoral blood and vitreous humor
- 2004
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In: Journal of Forensic Sciences. - 0022-1198 .- 1556-4029. ; 49:4, s. 820-825
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Journal article (peer-reviewed)abstract
- The stability of 46 drugs in postmortem femoral blood stored for one year at -20°C was investigated. The drugs included benzodiazepines, antidepressants, analgetics and hypnotics. For seven drugs we found a significant change in the concentration between the first and second analysis. Five substances; ethanol, desmethylmianserin, 7-amino-nitrazepam, THC and zopiclone showed a decrease in the concentration whereas the concentrations of two substances; ketobemidone and thioridazine increased. However, the changes observed were not of such an order that it would affect the interpretation in normal forensic casework. We also investigated the possible influence of potassium fluoride on the concentrations of the 46 drugs in vitreous humor after storage for one year. For two substances, ethanol and zopiclone, there were significantly lower concentrations in the samples without potassium fluoride. Furthermore, we also studied the correlation between the concentrations in femoral blood and vitreous humor. For 23 substances there was a significant difference between the concentrations in the vitreous humor and femoral blood. Significant correlations between the concentrations in these two specimens were found for 23 substances, indicating that vitreous humor can be an alternative specimen when blood samples are not available, provided that such correlation exists for the particular substance. Statistical analysis also revealed a correlation between the degree of protein binding of the different drugs and percentage of vitreous/femoral blood concentrations.
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| 9. |
- Kleman, Johan, et al.
(author)
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Rubbat förtroende för forskarna
- 2010
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In: Svenska Dagbladet. - 1101-2412. ; :25 maj
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Journal article (pop. science, debate, etc.)
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