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Almqvist, Sverker
Publications (2 of 2) Show all publications
Andersson, J., Renner, L., Sandin, J., Fors, C., Strand, N., Hjort, M., . . . Almqvist, S. (2011). Trafiksäkerhetspåverkan vid omkörning av 30-metersfordon. Linköping: Statens väg- och transportforskningsinstitut
Open this publication in new window or tab >>Trafiksäkerhetspåverkan vid omkörning av 30-metersfordon
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2011 (Swedish)Report (Other academic)
Alternative title[en]
Traffic safety effects when overtaking 30 metre trucks
Abstract [sv]

Trafikverket överväger att tillåta längre och tyngre fordon på vägarna förutsatt att de inte påverkar trafiksäkerheten negativt. Syftet med studien var att undersöka säkerhetseffekten av fordonslängd, speciellt med avseende på olycksrisken vid omkörningar. Intervjuade förare av en 30-meters timmerbil hade inte upplevt de farhågor som förare av normallånga lastbilar uttryckt i samband med trånga rondeller och korsningar, men de nämner betydelsen av stödjande åkeri, arbetsmiljö och fordonsutrustning. En simulatorstudie studerade bilförares omkörningar av ett 30- och ett 18,75-metersfordon på en 2+1-väg i situationen då två körfält går ihop till ett. Tidluckan till ett återstående körfält var i genomsnitt 0,2 s (sign.) kortare efter omkörningar av 30-metersfordonet i situationer då bakänden var i samma relativa position som för 18,75-metersfordonet vid början av omkörningen. En fältstudie analyserade videoinspelade omkörningar av en 30- och en 24-meters timmerbil på en 2+1-väg och en tvåfältig väg. Ingen signifikant skillnad i tidluckor kunde påvisas mellan omkörningar av de två fordonen för någon av vägtyperna. Det senare resultatet ska dock tolkas med försiktighet på grund av ojämnt distribuerad data som insamlats under specifika förhållanden. Slutsatserna är att det finns en liten tendens till negativ säkerhetseffekt vid omkörningar av längre fordon, och att fler fältstudier är nödvändiga.

Abstract [en]

The Swedish Road Administration considers permitting longer and heavier trucks on Swedish roads, provided that they do not affect traffic safety. The purpose of the study was to investigate the effect of truck length, particularly accident risk associated with overtaking. Interviewed drivers of 30 meter trucks had not experienced the problems predicted by drivers of ordinary trucks concerning narrow roundabouts and intersections, but mentioned the importance of a supportive truck company, working environment and truck equipment. A simulator study investigated car drivers overtaking trucks 30 m and 18.75 m long on a 2+1 road where two lanes merges to one. The headway time gap was 0.2 sec. (sign.) shorter after overtaking the 30 meter truck in situations where the back was in the same relative position as of the 18.75 meter truck. A field study analysed video-recorded overtakings of a 30 meter and a 24 meter timber truck on a 2+1 road and a two-lane road. No significant differences were found between headway time gaps when overtaking the two trucks, regardless of road type. The latter result should be interpreted with great caution because of unevenly distributed data collected during specific conditions. The conclusions are that longer trucks may have a small negative effect on overtaking situations, and that further field studies are required.

Place, publisher, year, edition, pages
Linköping: Statens väg- och transportforskningsinstitut, 2011. p. 64
Series
VTI rapport, ISSN 0347-6030 ; 732
Keywords
Lorry, Length, Overtaking, Risk, Safety, Vehicle spacing, Observation, Video camera, Simulator (driving), Test, Driver, Behaviour, Attitude (psychol), Interview, Lastbilar, Längd, Omkörning, Risk, Säkerhet, Avstånd mellan fordon, Observation, Videokameror, Körsimulatorer, Test, Förare, Beteende, Attityder, Intervjuer
National Category
Applied Psychology
Research subject
80 Road: Traffic safety and accidents, 841 Road: Road user behaviour; 80 Road: Traffic safety and accidents
Identifiers
urn:nbn:se:vti:diva-1814 (URN)
Available from: 2013-12-03 Created: 2013-12-03 Last updated: 2017-12-28Bibliographically approved
Anund, A., Ahlström, C., Almqvist, S. & Yahya, M.-R. (2009). Småskalig ITS: utvärdering av effekten av lokala VMS-system i tätort. Linköping: Statens väg- och transportforskningsinstitut
Open this publication in new window or tab >>Småskalig ITS: utvärdering av effekten av lokala VMS-system i tätort
2009 (Swedish)Report (Other academic)
Alternative title[en]
Evaluation of local ITS solutions in urban areas
Abstract [sv]

This study investigates the acceptance and effect of variable message signs (VMS). Two different systems were evaluated: one where a speed limit sign was combined with a message to slow down and another where a speed limit sign was combined with flashing lights. Both VMS were activated (lit up) if the passing vehicle was driving too fast as it approached the speed limit sign. The aim of the study was to evaluate if the use of a variable speed limit sign gave rise to lower speeds. The same approach was used in order to evaluate the effect of an additional message system or flashing lights. The investigation was conducted in two Swedish villages, Grästorp and Färgelanda, at road sections where the speed limit was momentarily reduced to 50 km/h. In both locations, the use of a variable speed limit sign resulted in speed reduction (mean and 85 percentiles) amongst the drivers. This means that the majority of the drivers, including those that drove much too fast, reduced their speed owing to the VMS. However, no further speed reductions were found when combining the variable speed limit signs with either a message system or flashing lights. Interviews with the drivers revealed that they believed that both VMS systems would increase traffic safety by reducing the speeds. They also stated that variable speed limit sign was enough to increase their awareness of the current speed limit and that no additional message systems or the blinking lights were necessary.

Place, publisher, year, edition, pages
Linköping: Statens väg- och transportforskningsinstitut, 2009. p. 49
Series
VTI rapport, ISSN 0347-6030 ; 646
Keywords
Variable message sign, Flashing light, Message, Driver information, Speed limit, Urban area, Driver, Behaviour, Average speed, Before and after study, Evaluation
National Category
Transport Systems and Logistics
Research subject
80 Road: Traffic safety and accidents, 841 Road: Road user behaviour; 80 Road: Traffic safety and accidents, 82 Road: Geometric design and traffic safety
Identifiers
urn:nbn:se:vti:diva-6493 (URN)
Available from: 2013-12-03 Created: 2013-12-03 Last updated: 2019-05-29Bibliographically approved
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