1. |
- Gustafsson, Mats, et al.
(författare)
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Effekter av vinterdäck : en kunskapsöversikt
- 2006
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Choice of winter tyres has, from mainly being a matter of safety and economic costs for wearing of road pavements, during later years also become a matter of inhalable particles formed during pavement wear from studded tyres and their negative effects on public health. Further, the tyres' effects on environment and noise have been illustrated in several studies. The issue is also complicated by the fact that tyre choice effects on traffic safety have several components, including such diverging parameters as friction and behaviour. Finally all aspects have to be evaluated from a socioeconomic point of view for society to be able to decide which kind of distribution of tyre types that is the most profitable. This report is a summary of current knowledge in this complex research field.
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2. |
- Nilsson, Göran, et al.
(författare)
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Huvudled och regleringar i korsningar
- 2005
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- På uppdrag av Vägverket har VTI närmare försökt belysa frågan om regleringar i korsningar och huvudledsbegreppet. När en väg klassas som huvudled följer automatiskt att korsningarna skall vara reglerade. Detta gäller hela huvudvägnätet. Det är också möjligt att klassa andra vägar eller vägavsnitt som huvudled. I det senare fallet är det primära syftet att införa reglering av anslutande vägar genom väjningsplikt eller stopplikt. Länsstyrelserna som fattar beslut om en väg skall vara huvudled får därför ansökningar om att införa huvudled på vissa vägar eller vägavsnitt. Om detta beslut överklagas görs detta till Vägverket VTI har försökt beskriva kunskapsläget, studerat körbeteendet vid olika regleringsformer i tätortskorsningar, analyserat kör- och hastighetsförlopp vid passage av reglerade korsningar och analyserat miljöeffekter av olika korsningsregleringar
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3. |
- Adamsson, Viola, et al.
(författare)
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Effects of a Nordic diet on cardiovascular and metabolic risk factors in hypercholesterolemic subjects: a randomized controlled study
- 2009
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Konferensbidrag (refereegranskat)abstract
- Background: Apart from lipid-lowering drugs, dietary changes can also reduce plasma LDL-C concentrations. No studies have been conducted to investigate the clinical effects of a diet with traditional foods originating from the Nordic countries. Method: In a randomised, controlled parallel-group intervention study 88 mildly hypercholesterolemic men and women were randomized to either an ad libitum Nordic diet (ND) or a control diet (CD) for 6 weeks. All meals and foods were provided to the participants in the ND group. Primary outcome measure was LDL-cholesterol, and secondary outcomes were blood pressure, plasma insulin and glucose concentrations. The ND was a high-fibre diet rich in plant foods (fruit, berries, vegetables, root vegetables, whole grain cereals and legumes), vegetable fats (rapeseed oil and nuts) and fatty fish, low-fat milk products, but low in salt, added sugars, saturated fats and red meats. Result: 86 subjects completed the study. Distribution of carbohydrates, fat and protein (E%) in ND was 54, 27, 19, respectively. ND lowered plasma total cholesterol 0.98±0.75 mmol/l (-16%), LDL-C by 0.83±0.67 mmol/l (-21%), HDL-C 0.08±0.23 mmol/l (-5%), including reduced LDL/HDL ratio by -0.42±0.57 (-14%) (all p<0.01 versus controls). Insulin concentrations decreased by 0.51± 2.25 (-9%, p=0.01) and systolic blood pressure by 7±13 mmHg (-5%, P<0.01) compared to controls. Despite diets were eaten ad libitum, body weight decreased by 3.0 kg in the ND (P<0.001). No significant differences were found for diastolic blood pressure, triglycerides or plasma glucose. Conclusion: A Nordic diet improves blood lipid profile, and insulin sensitivity as well as lowering blood pressure to a clinically significant extent in hypercholesterolemic subjects.
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4. |
- Hammarström, Ulf, et al.
(författare)
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Hastighetsregulator och bränsleförbrukning för tunga lastbilar med släp : försök med sänkning av maximal inställd hastighet från 89 till 85 km/h
- 2007
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Trucks with a gross vehicle weight above 12 tons and of year model 1988 or later shall as from 1992 be equipped with a speed regulator. The Road Administration, Region Skåne, made an agreement with a number of truck companies to set speed regulators with 85 km/h as maximum speed. The truck owners guaranteed that the speed regulators in the previous year were set at 89 km/h. The speed regulators were reset in June 2003. The agreement between the Road Administration and the truck owning companies included six companies and in all 17 trucks. Data on fuel fillings and odometer readings per month, both before and after the speed regulator resetting, was only available for 12 trucks belonging to five companies. The data analysis showed an increase in fuel consumption in the after situation. Different methods of analysis give somewhat different results with an increase of more than 3% at the most. The average air temperature in the after situation was somewhat higher than before the speed regulators were reset. The analyses show a temperature effect of 0.3% decrease in fuel consumption, from before to after.
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5. |
- Hammarström, Ulf, et al.
(författare)
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Motorhantering under stopptid : tomgång eller avstängning. Utsläpp under krypkörning: avgasmätningar och litteraturgenomgång
- 2005
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- There is a scarcity of data on which decisions can be based regarding thelimitation of idling during standstill periods. There is also reason tobelieve that the significance of engine management during standstill may varybetween different propulsion systems and technical standards etc, which willincrease the need for a decision base. The need for data that describe exhaustemissions during crawling speed is particularly great in the case of tunnels.Ventilation plants in tunnels are designed on the basis of relationshipsbetween emissions and mean speed. Up till now, for speeds below 30 km/h, theserelationships have not been satisfactorily based on measured data. The primaryobjective has been to fill the gaps in knowledge by exhaust measurements. Themethodology has comprised a survey of the literature, measurements andanalyses. Different objectives result in different limiting times for idlingduring standstill periods. For the vehicle fleet as a whole, different limitshave been estimated for different objectives: for private economy, 12 seconds;for macro economy overall, 23 seconds; for energy policy, 12 seconds, and forair quality, 36 seconds. There are also time limits per compound, pertechnical standard and per vehicle type. The time for diesel is shorter thanfor petrol engine. According to measurements, emission of oxides of nitrogen(NOx) at crawling speed varies over the range -51 and 171% for differentengine types when speed drops from 25 to 10 km/h. There are considerabledifferences in the speed dependence of fuel consumption both between andwithin studies. The relationships which could be estimated for particulateemissions do not, in any one case, indicate an increase in emission as speeddrops from 25 km/h.
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7. |
- Vierth, Inge, et al.
(författare)
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Långa och tunga lastbilars effekter på transportsystemet : redovisning av regeringsuppdrag
- 2008
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Rapport (populärvet., debatt m.m.)abstract
- I Sverige tillåts lastbilar i inrikestrafik som är upp till 25,25 meter långa och 60 ton tunga. Detta skiljer sig från EU-normen, där lastbilar som regel inte är längre än 18,75 meter och väger maximalt 40 ton. Näringsdepartementet har gett VTI i uppdrag att studera vilka samhällsekonomiska konsekvenser avvikelsen har medfört för Sverige samt beskriva konkurrensytan mellan väg- och järnvägstransporter. Effekterna på transportkostnader för näringslivet, avgas- och bulleremissioner, vägslitage, tidsfördröjning för bilister samt trafiksäkerheten har beräknats. En mycket stor andel av godstransporterna på väg utförs med fordon som överskrider EU-normen. Att krympa fordonsstorleken skulle leda till stora samhällsekonomiska förluster. Framför allt är det transportkostnaderna som ökar, men det skulle även uppkomma betydande kostnadsökningar inom områdena trafiksäkerhet, avgasemissioner och bulleremissioner. I utredningen konstateras att det är svårt, åtminstone på kort sikt, att åstadkomma överflyttningar mellan väg och järnväg. Detta beror delvis på att järnvägens kapacitet är högt utnyttjad.
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8. |
- Vierth, Inge, et al.
(författare)
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The effects of long and heavy trucks on the transport system : report on a government assignment
- 2008
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Trucks up to 25.25 metres in length and weighing up to 60 tonnes are permitted in domestic traffic in Sweden. This deviates from the EU standard, according to which trucks are not to be longer than 18.75 metres or weigh more than 40 tonnes. The Swedish Ministry of Enterprise, Energy and Communications has commissioned VTI to study what economic consequences this deviation has had for Sweden and to describe the competition interface between road and rail transport. The effects on transport costs for business, exhaust and noise emissions, road wear, time delay for motorists and road safety have been estimated. A very large proportion of freight transport by road takes place by vehicles that exceed the EU standard. Reducing vehicle size would lead to large economic losses. Transport costs would increase in particular, but significant cost increases would also occur in the areas of road safety, exhaust emissions and noise emissions. It is noted in the study that it is difficult, at least in the short term, to bring about transfers between road and rail. This is due, in part, to high rate of utilisation of the railway capacity.
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