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- Sternlund, Simon, 1983
(författare)
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The effectiveness of centerline rumble strips (CLRS) on two-lane carriageways in Sweden on injury accident risk for cars equipped with electronic stability control (ESC) and cars without ESC
- 2019
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Ingår i: Traffic Injury Prevention. - : Informa UK Limited. - 1538-957X .- 1538-9588. ; 20:8, s. 880-885
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Electronic Stability Control (ESC) and Lane Departure Warning (LDW) are in-vehicle safety systems that complement each other. While the implementation of on-board lane support systems in traffic is still limited and the majority of the traffic volume is made up by ESC-equipped cars, the effectiveness of centerline rumble strips (CLRS) for ESC-equipped cars need to be quantified. The aim of the present study is to estimate the effectiveness of CLRS on two-lane carriageways in Sweden, on injury accident risk for cars equipped with ESC and cars without ESC. Methods: Police reported injury crashes during 2011-2016 were extracted from the Swedish Traffic Accident Data Acquisition (STRADA) database and merged with the National Road Database (NVDB) containing information regarding road design and road use parameters. The analysis includes crashes on two-lane carriageways in Sweden with a width of at least seven meters in dry and wet road conditions, that is, road surface not covered by ice or snow. The crashes involved a total of 7,490 cars with injured drivers, where 39% of the cars were equipped with ESC. The effectiveness estimates were calculated for injured drivers in ESC-equipped cars in crashes involving drift out of lane to the left, and posted speed limits of 80 and 90 km/h. The analysis was carried out by applying the induced exposure approach in which rates of cars involved in crashes sensitive and non-sensitive to CLRS were compared at sites with and without CLRS. In order to substantiate the evidence for causality, case and control rates of car model year and Seat Belt Reminder (SBR) fitment, driver age, driver gender, traffic volume, road width, speed limit and road surface condition were compared. Results: For ESC-equipped cars, the analysis showed a reduction in CLRS-sensitive crashes by 40% (19-56%, confidence interval [CI] 95%) where CLRS had been implemented, and a reduction by 29% (11-44%, CI 95%) for cars without ESC-equipment. Conclusions: Contemporary effectiveness estimates may have important implications for the short and medium-term national road safety management. CLRS remains an important countermeasure to consider for reducing the number of real-world injury crashes. From a systematic safety perspective, it is important to accentuate that CLRS and ESC essentially address different crash scenarios. Still, both CLRS and ESC have the potential to avoid crashes involving unintentional lane drifting resulting in loss of control. When the CLRS alerts a driver of unintentional lane drifting, the ESC can be essential in supporting the driver to safely veer back into the lane without loss of control. However, further analysis on the combined safety benefit of ESC and CLRS is required.
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| 2. |
- Sternlund, Simon, 1983, et al.
(författare)
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The effectiveness of lane departure warning systems—A reduction in real-world passenger car injury crashes
- 2017
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Ingår i: Traffic Injury Prevention. - : Informa UK Limited. - 1538-957X .- 1538-9588. ; 18:2, s. 225-229
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The objective of this study was to estimate the safety benefits of in vehicle lane departure warning (LDW) and lane keeping aid (LKA) systems in reducing relevant real-world passenger car injury crashes. Methods: The study used an induced exposure method, where LDW/LKA-sensitive and nonsensitive crashes were compared for Volvo passenger cars equipped with and without LDW/LKA systems. These crashes were matched by car make, model, model year, and technical equipment; that is, low-speed autonomous emergency braking (AEB) called City Safety (CS). The data were extracted from the Swedish Traffic Accident Data Acquisition database (STRADA) and consisted of 1,853 driver injury crashes that involved 146 LDW-equipped cars, 11 LKA-equipped cars, and 1,696 cars without LDW/LKA systems. Results: The analysis showed a positive effect of the LDW/LKA systems in reducing lane departure crashes. The LDW/LKA systems were estimated to reduce head-on and single-vehicle injury crashes on Swedish roads with speed limits between 70 and 120 km/h and with dry or wet road surfaces (i.e., not covered by ice or snow) by 53% with a lower limit of 11% (95% confidence interval [CI]). This reduction corresponded to a reduction of 30% with a lower limit of 6% (95% CI) for all head-on and single-vehicle driver injury crashes (including all speed limits and all road surface conditions). Conclusions: LDW/LKA systems were estimated to lower the driver injury risk in crash types that the systems are designed to prevent; that is, head-on and single-vehicle crashes. Though these are important findings, they were based on a small data set. Therefore, further research is desirable to evaluate the effectiveness of LDW/LKA systems under real-world conditions and to differentiate the effectiveness between technical solutions (i.e., LDW and LKA) proposed by different manufacturers.
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| 3. |
- Sternlund, Simon, 1983
(författare)
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The Safety Potential and Effectiveness of Lane Departure Warning Systems in Passenger Cars
- 2018
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In the road transport system, crashes due to lane departure account for a large proportion of the most severe crashes that passenger car occupants are exposed to. While Electronic Stability Control (ESC) effectively prevents lane departure due to loss of control, lane departure due to unintentional drifting has not been addressed to the same extent. This thesis is based on two papers aimed at increasing the knowledge of the safety potential and effectiveness of lane keeping support. Paper 1 aims to identify and characterise lane departure crashes and identify the safety potential of lateral support systems such as Lane Departure Warning (LDW) by using real-world in-depth data of fatal crashes in Sweden. Single car, head-on and overtaking crashes involving lane departure without prior loss of control were categorised into intentional lane change, evasive manoeuvre or unintentional drift out of lane. The latter category accounted for half (51/100) of the single vehicle and head-on crashes and LDW systems have the potential to prevent a majority (33 to 38) of these crashes. Paper 2 aims to estimate the effectiveness of LDW in real-world passenger car injury crashes, extracted from the Swedish Traffic Accident Data Acquisition (STRADA). The induced exposure method and information of each individual car’s equipment were used. LDW halved the risk of being in a head-on or single passenger car driver injury crash where the posted speed limits were 70 km/h and above and where the road surface was not covered by ice or snow. This thesis shows results in line with other research considering the safety potential and effectiveness of lane keeping support. While related research used risk measure exposure such as insured vehicle days or vehicle miles travelled to estimate effectiveness of LDW, Paper 2 used induced exposure where the exposure is made up by non-sensitive crashes. The induced exposure method has advantages of incorporating possible changes in driver behaviour and usage rates in real-world traffic. Despite applying two very different methods of analysis, the two papers synthesised in this thesis show results that corroborate each other. In conclusion, LDW is part of a system where detectable lane markings provided by road authorities and vehicles technology have to work together and shows significant traffic safety benefits under certain conditions. As both components are dependent on each other to create safety, this makes safety the responsibility of both road authorities and the car industry. Lane keeping support systems, such as LDW, is one of the most important safety features in the foreseeable future, where the share of unintentional drifting crashes could be expected to increase due to ESC addressing loss of control. Therefore, different organisations and road safety stakeholders should promote the fitment of LDW systems in new cars and speed up the implementation in traffic.
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| 4. |
- Sternlund, Simon, 1983
(författare)
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The safety potential of lane departure warning systems - A descriptive real-world study of fatal lane departure passenger car crashes in Sweden
- 2017
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Ingår i: Traffic Injury Prevention. - : Informa UK Limited. - 1538-957X .- 1538-9588. ; 18, s. S18-S23
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Lane departure crashes account for a significant proportion of passenger car occupant fatalities and serious injuries. Utilizing real-world data involving fatal passenger car crashes in Sweden, the characteristics of lane departure crashes were identified and the safety potential of lane departure warning (LDW) systems was quantified.Methods: The material consisted of 104 in-depth studies of fatal passenger car crashes in 2010. The crashes were classified as single-vehicle (n = 48), head-on (n = 52), and overtaking (n = 4) crashes. These crash types were identified as crashes that could have potentially involved lane departure. A case-by-case analysis was carried out and lane departure crashes were identified and characterized using police reports and information collected by crash investigators at the Swedish Transport Administration; for example, inspections and photographs of the crash sites and of the involved vehicles. Lane departure crashes were separated from crashes where loss of control occurred pre-lane departure. Furthermore, loss of control post-lane departures were identified. When studying the pre-stage of lane departure without prior loss of control, crashes were categorized as unintentional drifting, intentional lane change, or evasive maneuver. Using previously published effectiveness information, the potential for LDW systems to prevent crashes was estimated.Results: Of all crashes with passenger car occupant fatalities in Sweden in 2010, 46% (63/138) were found to relate to lane departure without prior loss of control. These crashes accounted for 61% (63/104) of all single-vehicle, head-on, and overtaking crashes. The remaining 41 crashes were due to loss of control pre-lane departure. Unintentional drifting accounted for 81% (51/63) of all lane departure crashes without prior loss of control, which corresponded to 37% (51/138) of all fatal passenger car occupant crashes. LDW systems were found to potentially prevent 33-38 of the 100 fatal head-on and single vehicle crashes. These crashes involved drifting and occurred on roads with visible lane markings, signed posted speed limits 70km/h, and without rumble strips on the corresponding lane departure side. The range of potentially prevented crashes (33-38) is due to the inclusion or exclusion of crashes involving excessive speeding.Conclusions: In this study, approximately half (51/100) of all head-on and single-vehicle crashes were identified as being a consequence of drifting, where LDW systems had the potential to prevent the majority (33-38) of these crashes. The typical lane departure crash without prior loss of control occurred on undivided roads in rural areas with signed posted speed limits 70km/h, where the center and side road markings were visible.
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| 5. |
- Strandroth, Johan, 1978, et al.
(författare)
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Characteristics of future crashes in Sweden – identifying road safety challenges in 2020 and 2030
- 2016
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Ingår i: 2016 IRCOBI Conference Proceedings - International Research Council on the Biomechanics of Injury. - : International Research Council on the Biomechanics of Injury. ; , s. 47-60
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Konferensbidrag (refereegranskat)abstract
- It has been proposed by the European Commission that the number of road fatalities within the European Union should move close to zero by 2050. In response to that, Sweden has set out to revise the national road safety targets of 2020 and 2030. In order to address future safety challenges, there is a need to consider the characteristics of future crashes. The objective of this study was therefore to quantify and investigate the characteristics of severe crashes in 2020 and 2030. Injury crashes were reduced from a baseline in 2014 to a given time in the future based on the implementation of safety interventions. The material consisted of hospital admission data with AIS diagnoses. Results show that the actions planned to be taken in Sweden between now and 2020 and 2030 will continue to increase the safety level for car occupants, but are estimated to be insufficient for vulnerable road users. It was concluded that there is a need to define a safety system for vulnerable road users that takes a holistic approach to sustainability by including both injury prevention measures and measures to encourage more health-promoting and fossil-free modes of transport.
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