Traffic safety risks with EU-semitrailers on slippery roads.
Safety gains for heavy trailers from increased crossfall in road curves.
C/B-analysis: Increasing crossfall is profitable.
Wide shoulder: Effective “barrier” to crashes.
Sweden implementing new pavement condition parameter "Rut Bottom Cross Slope Variance" (tvärfallsvariation) in 2016.
Improved heavy vehicle safety by increased lane widening in curves.
Cutting fuel consumption tenfold per cents, by repair of road damages
HVTT14 Investigating Heavy Vehicle Rollover Crashes and the Influence of Road...Johan Granlund
Presentation at HVTT14 of a paper by Johan Granlund at WSP Parsons Brinckerhoff, Rob di Cristoforo at Advantia Transport Consulting, Rolf Mellum and Marius Hansen Raddum at Accident Investigation Board Norway.
Investigating Heavy Vehicle Rollover Crashes and the Influence of Road DesignJohan Granlund
Paper presented at the International Heavy Vehicle Transport Technology HVTT14 Symposia in Rotorua, New Zealand, in Nov 2016.
The HVTT conferences are organized by the International Forum for Road Transport Technology, IFRTT.
Traffic Safety Risks with EU Tractor-Semitrailer Rigs on Slippery Roads, HVTT14Johan Granlund
Heavy goods vehicles (HGV) for long haulage within the EU Nordic countries have due to regional evolution mostly been straight trucks with drawbar trailers. In the past decade, there has been a significant increase in articulated EU tractor/semitrailer rigs within the Nordic countries, a trend driven by lower freight costs when using low paid drivers from Eastern Europe. Heavy trucks are often involved in crashes and traffic jams on ice-slippery winter roads. An ever-increasing number of voices are stating that the articulated vehicles present disproportionate high traffic safety risks on icy winter roads. This paper discusses some regulatory & design factors that partially explain why EU semitrailer rigs are particularly associated with jamming long steep icy upgrades, and with loss-of-control crashes such as jackknifing and trailer swing. A novel analysis was made with TruckSim software. Preliminary results support the opinion that EU semitrailer rigs are an unsafe vehicle combination on slippery roads. This finding calls for deeper research about the winter road safety risks with the EU trac-tor/semitrailer vehicle combination, as well as on how to mitigate its safety risks. Results from such research are likely to be useful arguments for modifying the EU directive 96/53/EC, so that tractor units with longer wheelbase can be used without conflict on trailer length and payload volume.
Presented at the International Heavy Vehicle Transport Technology Symposia HVTT14 in Rotorua, New Zeeland, nov 2016.
Health Issues Raised by Poorly Maintained Road Networks - ROADEX IIIJohan Granlund
The EU ROADEX Project 1998 - 2007 is a trans-national roads co-operation aimed at developing
ways for interactive and innovative management of low traffic volume roads throughout the
cold climate regions of the Northern Periphery Area of Europe. Its goals have been to facilitate
co-operation and research into the common problems of the Northern Periphery.
The overall objective for this research task was to increase the understanding for road user’s
health risks when riding on roads in poor condition. Better knowledge will facilitate the reduction
of the risks, by means of improved pavement management, more conscious truck, bus and ambulance
operations, and inspire to vehicle suspension systems improvements.
The report commences with generic descriptions of how safety and health can be affected by
ride vibration, how truck suspension systems isolate and amplify vibration at various frequencies,
and how pavement properties, such as cross slope, control the important forces at work.
A case study is reported from the Beaver Road 331 in northern Sweden. A heavy timber logging
truck was instrumented to measure ride vibration and direction. Measurements were taken at a
range of points (seat, cab, frame and wheels) and the results stored together with data on
speed and interior noise. Ride vibration data from repeated rides over a 280 km long round trip
from forest to coast industries was then compared with reference data on pavement condition,
scanned by a laser/inertial Profilograph. Results obtained included:
• The daily exposure to Whole-Body Vibration, the A(8)-value, for timber truck drivers riding
constantly on roads such as Rd 331 were unacceptably high, when compared to the
health and safety Action Value in Directive 2002/44/EC.
• The truck drivers were exposed to unacceptably health risks in the back when driving at
modest speed over the worst bumps, due to high spinal compression doses, Sed, as per
the ISO 2631-5 standard.
• A derived draft limit of 0.30 % for undesired variance in cross slope. This could be useful
in pavement management to prevent roll-motion and lateral forces in road vehicles.
The case study also produced valuable spin-offs in new methods for analyzing traffic safety
risks arising from incorrectly banked curves and low drainage gradients. Hospital records from
accidents at Rd 331 (mainly skid accidents) were found to match road sections with high cross
slope variance, curves with incorrect superelevation, transition sections with low drainage gradients,
and sections with high skid risk due to low/varying Macro Texture. These serious findings
call for both short and long term actions. Road agencies should use the demonstrated methods
to quickly identify hazardous sites and warn road users of them. Road repair planning and practices
should be improved, and funding for road repair should be increased.
ITS (Intelligent Transportation Systems): add information and communications technology to transport infrastructures and vehicles in an effort to improve their safety, reliability, efficiency and quality.
HVTT14 Investigating Heavy Vehicle Rollover Crashes and the Influence of Road...Johan Granlund
Presentation at HVTT14 of a paper by Johan Granlund at WSP Parsons Brinckerhoff, Rob di Cristoforo at Advantia Transport Consulting, Rolf Mellum and Marius Hansen Raddum at Accident Investigation Board Norway.
Investigating Heavy Vehicle Rollover Crashes and the Influence of Road DesignJohan Granlund
Paper presented at the International Heavy Vehicle Transport Technology HVTT14 Symposia in Rotorua, New Zealand, in Nov 2016.
The HVTT conferences are organized by the International Forum for Road Transport Technology, IFRTT.
Traffic Safety Risks with EU Tractor-Semitrailer Rigs on Slippery Roads, HVTT14Johan Granlund
Heavy goods vehicles (HGV) for long haulage within the EU Nordic countries have due to regional evolution mostly been straight trucks with drawbar trailers. In the past decade, there has been a significant increase in articulated EU tractor/semitrailer rigs within the Nordic countries, a trend driven by lower freight costs when using low paid drivers from Eastern Europe. Heavy trucks are often involved in crashes and traffic jams on ice-slippery winter roads. An ever-increasing number of voices are stating that the articulated vehicles present disproportionate high traffic safety risks on icy winter roads. This paper discusses some regulatory & design factors that partially explain why EU semitrailer rigs are particularly associated with jamming long steep icy upgrades, and with loss-of-control crashes such as jackknifing and trailer swing. A novel analysis was made with TruckSim software. Preliminary results support the opinion that EU semitrailer rigs are an unsafe vehicle combination on slippery roads. This finding calls for deeper research about the winter road safety risks with the EU trac-tor/semitrailer vehicle combination, as well as on how to mitigate its safety risks. Results from such research are likely to be useful arguments for modifying the EU directive 96/53/EC, so that tractor units with longer wheelbase can be used without conflict on trailer length and payload volume.
Presented at the International Heavy Vehicle Transport Technology Symposia HVTT14 in Rotorua, New Zeeland, nov 2016.
Health Issues Raised by Poorly Maintained Road Networks - ROADEX IIIJohan Granlund
The EU ROADEX Project 1998 - 2007 is a trans-national roads co-operation aimed at developing
ways for interactive and innovative management of low traffic volume roads throughout the
cold climate regions of the Northern Periphery Area of Europe. Its goals have been to facilitate
co-operation and research into the common problems of the Northern Periphery.
The overall objective for this research task was to increase the understanding for road user’s
health risks when riding on roads in poor condition. Better knowledge will facilitate the reduction
of the risks, by means of improved pavement management, more conscious truck, bus and ambulance
operations, and inspire to vehicle suspension systems improvements.
The report commences with generic descriptions of how safety and health can be affected by
ride vibration, how truck suspension systems isolate and amplify vibration at various frequencies,
and how pavement properties, such as cross slope, control the important forces at work.
A case study is reported from the Beaver Road 331 in northern Sweden. A heavy timber logging
truck was instrumented to measure ride vibration and direction. Measurements were taken at a
range of points (seat, cab, frame and wheels) and the results stored together with data on
speed and interior noise. Ride vibration data from repeated rides over a 280 km long round trip
from forest to coast industries was then compared with reference data on pavement condition,
scanned by a laser/inertial Profilograph. Results obtained included:
• The daily exposure to Whole-Body Vibration, the A(8)-value, for timber truck drivers riding
constantly on roads such as Rd 331 were unacceptably high, when compared to the
health and safety Action Value in Directive 2002/44/EC.
• The truck drivers were exposed to unacceptably health risks in the back when driving at
modest speed over the worst bumps, due to high spinal compression doses, Sed, as per
the ISO 2631-5 standard.
• A derived draft limit of 0.30 % for undesired variance in cross slope. This could be useful
in pavement management to prevent roll-motion and lateral forces in road vehicles.
The case study also produced valuable spin-offs in new methods for analyzing traffic safety
risks arising from incorrectly banked curves and low drainage gradients. Hospital records from
accidents at Rd 331 (mainly skid accidents) were found to match road sections with high cross
slope variance, curves with incorrect superelevation, transition sections with low drainage gradients,
and sections with high skid risk due to low/varying Macro Texture. These serious findings
call for both short and long term actions. Road agencies should use the demonstrated methods
to quickly identify hazardous sites and warn road users of them. Road repair planning and practices
should be improved, and funding for road repair should be increased.
ITS (Intelligent Transportation Systems): add information and communications technology to transport infrastructures and vehicles in an effort to improve their safety, reliability, efficiency and quality.
GreenSwirl: Combining Traffic Signal Control and Route Guidance for Reducing ...Naoki Shibata
Jiaxing Xu, Weihua Sun, Naoki Shibata and Minoru Ito : "GreenSwirl: Combining Traffic Signal Control and Route Guidance for Reducing Traffic Congestion," in Proc. of IEEE Vehicular Networking Conference 2014 (IEEE VNC 2014), pp. 179-186.
Serious traffic congestion is a major social problem in large cities. Inefficient setting of traffic signal cycles, especially, is one of the main causes of congestion. GreenWave is a method for controlling traffic signals which allows one-way traffic to pass through a series of intersections without being stopped by a red light. GreenWave was tested in several cities around the world, but the results were not satisfactory. Two of the problems with GreenWave are that it still stops the crossing traffic, and it forms congestion in the traffic turning into or out of the crossing streets. To solve these problems, we propose a method of controlling traffic signals, GreenSwirl, in combination with a route guidance method, GreenDrive. GreenSwirl controls traffic signals to enable a smooth flow of traffic through signals times to turn green in succession and through non-stop circular routes through the city. The GreenWave technology is extended thereby. We also use navigation systems to optimize the overall control of the city's traffic. We did a simulation using the traffic simulator SUMO and the road network of Manhattan Island in New York. We confirmed that our method shortens the average travel time by 10%-60%, even when not all cars on the road are equipped to use this system.
Eskom Coal Logistics Overview. Presented by Nico Singh during the 2nd Annual Coal Transportation Africa Summit held in Johannesburg, South Africa on 20 May 2015.
(Slides) A Method for Pedestrian Position Estimation using Inter-Vehicle Comm...Naoki Shibata
http://ito-lab.naist.jp/themes/ITS/pdfs/2-1/1.pdf
Sawa, Y., Kitani, T., Shibata, N., Yasumoto, K., Ito, M.:
A Method for Pedestrian Position Estimation using Inter-Vehicle Communication, Proc. of the 3rd IEEE Workshop on Automotive Networking and Applications (AutoNet 2008), pp. 1 - 6, DOI:10.1109/GLOCOMW.2008.ECP.57 (Dec 2008).
In this paper, we propose a method for detecting the positions of pedestrians by cooperation of multiple cars with directional antennas to support drivers for pedestrian safety. In the method, each pedestrian carries a device which periodically transmits a beacon with a unique ID, and each car passing near the pedestrian receives the beacon by a directional antenna and measures the distance and the angle of arrival.
We assume the distribution of the measurement errors to be a normal distribution, and the system calculates the existence probabilities of each pedestrian at each point. By exchanging information of the probabilities between cars, the area with high existence probability is narrowed down. In this paper, we first describe the situations where detecting positions of pedestrians greatly contribute to pedestrian safety, and then we describe the probability model used in our method, the method for calculating existence probabilities from information from multiple cars, and the protocol for exchanging the probability information between cars. We evaluated our method on QualNet simulator, and confirmed that the positions can be detected accurately enough for practical uses.
Impact of climbing lanes on average travel speedCandia John
Two-lane highways constitute a large percentage of the total road network in Uganda (National Roads 10,000 Km, District Roads 27,500 Km and Urban Roads 4,800 Km).
Fast moving vehicles get delayed as they are unable to overtake slow moving vehicles hence they move in platoons.
HGV induce frequent gaps of excessive length both in front and behind themselves thereby affecting the speed of vehicles and their spacing.
Weigh-in-motion systems are used to determine the weight of vehicle while it is in motion. It is used for vehicle overweight enforcement. Various classifications and types of WIM systems - pavement-based, bridge-based, low-speed and high-speed WIM etc are included. Status of WIM implementation in India is also stated in the presentation
https://youtu.be/Hfq6J29BLnc
Presentation by Dr James Tate to IAQM Air Quality Conference October 2015.
http://iaqm.co.uk/event/routes-to-clean-air-air-quality-conference-2015
https://youtu.be/1WVelwAEg-c
www.its.leeds.ac.uk/people/j.tate
Presentation by Dr James Tate at Institute of Air Quality Management (IAQM) Dispersion Modellers User Group December 2014.
www.its.leeds.ac.uk/people/j.tate
http://iaqm.co.uk/event/dmug-2014/
Bearing capacity at the pavement side - the NVF method, HVTT12 Granlund et alJohan Granlund
Traditional pavement bearing capacity analysis is based on an assumption of infinite geometry without any road edge; ”geometric compatibility”. This simplification leads to systematic under-dimensioned pavements at roads with narrow shoulders. The need for a model for analysis of bearing capacity at the road edge was pointed out by Nils Odemark already in 1956. As showed in the WAASHO Road Test in 1955, roads with weak edges exhibit fast deterioration, resulting in damages such as rutting, cracking and roughness in the outer (truck) wheel path. In Sweden, some 10 % of budgets for maintenance of paved roads are spent on repair of road edge deformations. For truckers, road edge damages on narrow roads bring serious risk for loss-of-control crashes. The crash type where most truck drivers are injured is the rollover. A high CoG makes heavy trucks prone to lateral forces, such as from roll-vibration at non-uniform road edge deformations. In the Nordic countries, over 1 000 truck rollovers occur every year. Roll-related lateral buffeting is particularly hazardous on ice-slippery surfaces, as it may cause the truck (or driver, by improper manoeuvring) to skid. Sustainable road edges require a relevant method for analysis of bearing capacity. Such a method has been in use in Denmark for decades. This method is based on classic geo-technological analysis as established by Terzaghi, and it has now been updated. The model shows that with regular 0.25 m shoulder, the outer wheel path may have as little as 45 % of the bearing capacity at the road centre. Sensitivity analysis shows that key factors are slope towards ditch, shoulder width, depth of ditch and pavement bearing capacity at the road centre. The method is currently being reviewed in the Norwegian Durable Roads programme, where achieving stable road edges have been given top priority. The insight from the sensitivity analysis has also made an immediate impact on the largest road reinforcement project ever in Sweden, the 157 km Pajala iron ore express road, a road that will be serving a 90 ton high-capacity truck every 7´th minute starting in 2013. The method for analysis of bearing capacity at the road edge is published as Nordic Road Association´s Report 04/2012.
GreenSwirl: Combining Traffic Signal Control and Route Guidance for Reducing ...Naoki Shibata
Jiaxing Xu, Weihua Sun, Naoki Shibata and Minoru Ito : "GreenSwirl: Combining Traffic Signal Control and Route Guidance for Reducing Traffic Congestion," in Proc. of IEEE Vehicular Networking Conference 2014 (IEEE VNC 2014), pp. 179-186.
Serious traffic congestion is a major social problem in large cities. Inefficient setting of traffic signal cycles, especially, is one of the main causes of congestion. GreenWave is a method for controlling traffic signals which allows one-way traffic to pass through a series of intersections without being stopped by a red light. GreenWave was tested in several cities around the world, but the results were not satisfactory. Two of the problems with GreenWave are that it still stops the crossing traffic, and it forms congestion in the traffic turning into or out of the crossing streets. To solve these problems, we propose a method of controlling traffic signals, GreenSwirl, in combination with a route guidance method, GreenDrive. GreenSwirl controls traffic signals to enable a smooth flow of traffic through signals times to turn green in succession and through non-stop circular routes through the city. The GreenWave technology is extended thereby. We also use navigation systems to optimize the overall control of the city's traffic. We did a simulation using the traffic simulator SUMO and the road network of Manhattan Island in New York. We confirmed that our method shortens the average travel time by 10%-60%, even when not all cars on the road are equipped to use this system.
Eskom Coal Logistics Overview. Presented by Nico Singh during the 2nd Annual Coal Transportation Africa Summit held in Johannesburg, South Africa on 20 May 2015.
(Slides) A Method for Pedestrian Position Estimation using Inter-Vehicle Comm...Naoki Shibata
http://ito-lab.naist.jp/themes/ITS/pdfs/2-1/1.pdf
Sawa, Y., Kitani, T., Shibata, N., Yasumoto, K., Ito, M.:
A Method for Pedestrian Position Estimation using Inter-Vehicle Communication, Proc. of the 3rd IEEE Workshop on Automotive Networking and Applications (AutoNet 2008), pp. 1 - 6, DOI:10.1109/GLOCOMW.2008.ECP.57 (Dec 2008).
In this paper, we propose a method for detecting the positions of pedestrians by cooperation of multiple cars with directional antennas to support drivers for pedestrian safety. In the method, each pedestrian carries a device which periodically transmits a beacon with a unique ID, and each car passing near the pedestrian receives the beacon by a directional antenna and measures the distance and the angle of arrival.
We assume the distribution of the measurement errors to be a normal distribution, and the system calculates the existence probabilities of each pedestrian at each point. By exchanging information of the probabilities between cars, the area with high existence probability is narrowed down. In this paper, we first describe the situations where detecting positions of pedestrians greatly contribute to pedestrian safety, and then we describe the probability model used in our method, the method for calculating existence probabilities from information from multiple cars, and the protocol for exchanging the probability information between cars. We evaluated our method on QualNet simulator, and confirmed that the positions can be detected accurately enough for practical uses.
Impact of climbing lanes on average travel speedCandia John
Two-lane highways constitute a large percentage of the total road network in Uganda (National Roads 10,000 Km, District Roads 27,500 Km and Urban Roads 4,800 Km).
Fast moving vehicles get delayed as they are unable to overtake slow moving vehicles hence they move in platoons.
HGV induce frequent gaps of excessive length both in front and behind themselves thereby affecting the speed of vehicles and their spacing.
Weigh-in-motion systems are used to determine the weight of vehicle while it is in motion. It is used for vehicle overweight enforcement. Various classifications and types of WIM systems - pavement-based, bridge-based, low-speed and high-speed WIM etc are included. Status of WIM implementation in India is also stated in the presentation
https://youtu.be/Hfq6J29BLnc
Presentation by Dr James Tate to IAQM Air Quality Conference October 2015.
http://iaqm.co.uk/event/routes-to-clean-air-air-quality-conference-2015
https://youtu.be/1WVelwAEg-c
www.its.leeds.ac.uk/people/j.tate
Presentation by Dr James Tate at Institute of Air Quality Management (IAQM) Dispersion Modellers User Group December 2014.
www.its.leeds.ac.uk/people/j.tate
http://iaqm.co.uk/event/dmug-2014/
Bearing capacity at the pavement side - the NVF method, HVTT12 Granlund et alJohan Granlund
Traditional pavement bearing capacity analysis is based on an assumption of infinite geometry without any road edge; ”geometric compatibility”. This simplification leads to systematic under-dimensioned pavements at roads with narrow shoulders. The need for a model for analysis of bearing capacity at the road edge was pointed out by Nils Odemark already in 1956. As showed in the WAASHO Road Test in 1955, roads with weak edges exhibit fast deterioration, resulting in damages such as rutting, cracking and roughness in the outer (truck) wheel path. In Sweden, some 10 % of budgets for maintenance of paved roads are spent on repair of road edge deformations. For truckers, road edge damages on narrow roads bring serious risk for loss-of-control crashes. The crash type where most truck drivers are injured is the rollover. A high CoG makes heavy trucks prone to lateral forces, such as from roll-vibration at non-uniform road edge deformations. In the Nordic countries, over 1 000 truck rollovers occur every year. Roll-related lateral buffeting is particularly hazardous on ice-slippery surfaces, as it may cause the truck (or driver, by improper manoeuvring) to skid. Sustainable road edges require a relevant method for analysis of bearing capacity. Such a method has been in use in Denmark for decades. This method is based on classic geo-technological analysis as established by Terzaghi, and it has now been updated. The model shows that with regular 0.25 m shoulder, the outer wheel path may have as little as 45 % of the bearing capacity at the road centre. Sensitivity analysis shows that key factors are slope towards ditch, shoulder width, depth of ditch and pavement bearing capacity at the road centre. The method is currently being reviewed in the Norwegian Durable Roads programme, where achieving stable road edges have been given top priority. The insight from the sensitivity analysis has also made an immediate impact on the largest road reinforcement project ever in Sweden, the 157 km Pajala iron ore express road, a road that will be serving a 90 ton high-capacity truck every 7´th minute starting in 2013. The method for analysis of bearing capacity at the road edge is published as Nordic Road Association´s Report 04/2012.
Презентация для доклада, сделанного на открытии фотовыставки, посвященной экспедиции в Ливию и Тунис, 2010 год. Дополнительная информация к презентации расположена в заметках к каждому слайду
Lowered crash risk with banked curves designed for heavy trucks, granlund et ...Johan Granlund
Slides from the presentation at HVTT13 in San Luis (Argentina) of our paper with the same title. Note that the full paper is available here at Slideshare.
Hvtt13 granlund et al lowered crash risk with banked curves designed for heav...Johan Granlund
Outer-curves are banked into superelevation in order to reduce the crash risk due to high demand for side friction between tyres and road. Road design codes use analysis of cornering forces acting on a point-mass model of a vehicle, where the Centre-of-Gravity (CoG) is assumed to be located at the tyre footprint. This may be relevant for low passenger cars. The scope here was to investigate the need for superelevation for heavy goods vehicles (HGV) with high CoG. The study used a vehicle model including both vertical and lateral position of CoG, as well as road split friction under left/right wheels. The results showed that superelevation demand increases with height and lateral displacement of CoG, and peaks when the curve is more slippery under outer wheels than under inner wheels. A conclusion was that the traditional point-mass “car model” can underestimate the superelevation needed for safe HGV operations. The paper recommends some improvements in road design codes for new curves, as well as some actions to improve safety in existing curves.
Reduced Pavement Service Life - Causes and Costs, HVTT15 paperJohan Granlund
Pavement loads and road wear have become hot topics in Sweden, due to both an increase of gross combination weight to 74 tonnes and a governmental investigation on a new road wear fee for heavy vehicles. To balance the governmental investigation, the road haulage industry made an independent expert investigation on causes and costs of reduced pavement service life. This paper summarizes the expert report into English. A literature study on factors that cause shortened pavement life cycle explain causes of non-traffic related damages. The annual total cost for maintenance of paved state roads in Sweden was in this investigation split into repair of traffic load related damages and of non-traffic related damages. A reference cost for road damage from heavy vehicles was estimated, by dividing costs for traffic load related damages with heavy vehicle traffic work. Using the Fourth Power Law, the road damaging effect of eleven heavy vehicle combinations were calculated while considering also axle and tyre configurations. Finally, the reference cost for repair of traffic load related damages was distributed to each vehicle combination. Hereby it became possible to compare the estimated vehicle specific cost for road damage versus the fee proposed by the governmental investigation. The ratio between state accounted cost for road damage from heavy vehicles and state proposed fee for road wear is about 1:8. This showed that the proposed fee is very high, being a tax rather than representing true cost coverage. After the industry reported this finding, the government withdrew their investigation on a fee.
Safer Curves On Multiple Lane Roads GranlundJohan Granlund
Many road users have crashed at high speed in sharp curves during slippery road conditions. To reduce the skid risk following high lateral forces, outercurves are banked into superelevation. Road designers are guided by design codes into what superelevation values to select among, given a reference speed and curve radius. Curve design codes are based on analysis of cornering forces acting on AASHO’s point-mass model of a vehicle. While the design codes typically yield curves with acceptable safety level, there is a systematic problem with skid accidents on multiple lane curves. This paper discusses a causal factor and recommends changes in curve design codes as well as actions to improve safety in existing unsafe curves. Current road design practise approximates the vehicle travelled path (and thus lateral force) by the road curvature, which is reasonable on small roads. On multiple lane roads however, many drivers are changing lane also in sharp curves since no oncoming traffic is present. When shifting lane quickly, the vehicle experience a transient “curve radius” much sharper than indicated by the road curve radius. This can yield higher lateral force than the road design code have considered. Then the superelevation may be insufficient - when the road is slippery - to outbalance the cornering force. As a rule by thumb, sharp curves on multiple lane roads with high speed traffic should have maximum allowed cross slope in order to increase stability.
Vehicle and human vibration due to road condition - ROADEX IVJohan Granlund
This present ROADEX IV follow-up report describes results from demonstration projects in Scotland, Finland, Norway and Sweden over the period 2010 to 2012, where the case study from the Beaver Road 331 in ROADEX III has been reproduced. This document also reports on a study of the influence of road maintenance standard on truck ride vibration and vehicle internal noise, with special focus on winter road condition. Furthermore it reports on a study on vibration isolation from road to truck driver’s seat, by use of a Tyre Pressure Control System (TPCS). All measurements were carried out in the period 2010 - 2012.
A high repeatability between similar truck round trips was confirmed when using the ROADEX method to assess truck drivers’ daily vibration exposure A(8). Results from measurements of truck ride quality during the demonstrations included:
* Unacceptably high levels of driver´s daily vibration dose A(8) were recorded in all of the ROADEX Partner areas (the Norwegian E6-measurements were lower than the others but still at about the EU Action Value).
* Significant compression stress in the truck drivers spine were recorded at severe road damages, such as sharp frost heaves, settlements at bridges and culverts, improper
road/bridge joints and uneven transversal joints at both old and new asphalt repairs.
* In all Partner areas, intense truck roll vibration and lateral buffeting was recorded. This confirmed a special health and safety problem in the EU Northern Periphery (NP) cold
climates.
* The pavement condition parameter RBCSV (a “truck roll vibration indicator”) was further validated in addition to the previous ROADEX III study in Sweden. At sites with very high RBCSV, there is a risk that cargo latches might break due to high lateral acceleration.
* Winter conditions in the NP can result in significant corrugations in thick ice covering nonsalted roads, and extremely uneven frost heaves. The project results show that these conditions can make the ride vibration and noise much worse than during summer conditions.
* The use of a Tyre Pressure Control System (TPCS) has previously been shown to reduce ride vibration. The present study used a more detailed analysis to quantify the TPCS vibration isolating effect. Results from Scotland and Sweden show that TPCS was very efficient in isolating “shake” vibration from short wave road roughness (megatexture < 0.5 m) such as potholes and corrugated ice surfaces.
* Vehicle body “bounce” vibration with lower frequencies (1 – 3 Hz) were not isolated by the TPCS. Such low frequency bounce vibration can only be reduced by pavement maintenance.
* High side friction demand due to improperly banked horizontal curves was found to be a contributing factor behind many loss-of-control crashes, including rollovers.
* Several curves with tragic crash records were found to be improperly banked despite being newly resurfaced.
Many truck drivers are exposed to high stress from human whole-body vibration (WBV), thus suffering risk for stress-related heart diseases and for musculoskeletal problems in the neck, shoulders and back. Furthermore they are at high risk of being involved in road crashes. In the ROADEX IV project, sampling has been made of WBV-exposure of truck drivers on 3700 km typical truck transport routes in four EU Northern Periphery areas. The scope was to demonstrate assessment of daily vibration exposure A(8)-value, as well as of spinal compression stress Sed in drivers exposed to transient shock at bumps, and compare results with the Action Value in EU Health & Safety Directive 2002/44/EC. Results from Finland, Scotland and Sweden confirm that the EU Action Value A(8) = 0.5 m/s2 is exceeded. After normalization to all-year-conditions, also data from E6 in northern Norway exceeds the Action Value. Thus hauliers with employees working under conditions similar to the tested are obliged by law to make proper assessment of the risks from high vibration exposure, including elevated crash risk due to lateral buffeting on icy winter roads.
وبینار آینده ایمنی حمل و نقل
Richard Cuerden, Chief Scientist (Engineering & Technology), TRL
http://transportsafety.ir
حمید مرادی
Hamid Moradi
http://transportsafety.ir/category/vehicle-safety
EMBARQ Türkiye Yol Güvenliği Projeleri Yöneticisi Celal Tolga İmamoğlu, CODATU 2015'in Barselona, Zahle ve Beyrut'tan vaka incelemelerinin olduğu 'Road Safety and Security in Cities' oturumunda EMBARQ Türkiye'nin beş ilimizde yürüttüğü Yol Güvenliği Laboratuvarı Projesi'ni anlattı. Yapılan önerilerle, 70 kişinin hayatı kurtarılırken, 500 çarpışmanın da engellenebileceği öngörülüyor.
CODATU 2015: Enerji, İklim ve Hava Kalitesi Sorunu: Gelişmekte olan Ülkelerde Kent içi Ulaşım Politikalarının Rolü
EMBARQ Turkey Road Safety Projects Manager Celal Tolga İmamoğlu presented RSLab (Road Safety Laboratory) Project that EMBARQ Turkey has implemented in 5 cities in Turkey, during 'Road Safety and Security in Cities' session of CODATU 2015 containing case studies from Barcelona, Zahle and Beirut. According to the recommendations, 70 lives will be saved and 500 crashes will be prevented.
CODATU 2015: Energy, Climate and Air Quality Challenge: The Role of Urban Transport Policies in Developing Countries
Reducing health and safety risks on poorly maintained rural roads, granlundJohan Granlund
This paper presents a handful of methods to measure road alignment properties and pavement damages that bring health and safety risks. These methods can be used in new approaches to reduce disproportionally high risks in hot spots on the low-volume road network. Suitable actions include road curve reconstruction, reinforcement of road edge or entire pavement, resurfacing or retexturing the wearing course, as well as mounting intelligent warning signs using radar for detection of excessive vehicle speed. The potential for crash reduction is high at hot spot road sections, especially where friction is low. This paper ends with a consensus statement on the urgent need to implement such approaches in road management. The statement is given by the Nordic Road Associations (NVF) working group “Vehicles and Transportation”, consisting of about 50 recognized experts in the fields of heavy vehicles, transportation and of vehicle-road interaction
A 5-part course for university or engineering students on transport and mobility issues (history, current situation, theoretical concepts, future and the Finnish case)
Dr Glyn Rhys-Tyler - Road vehicle exhaust emissions; 'an age of uncertainty' ...IES / IAQM
DMUG remains the key annual event for experts in this field. Unmissable speakers will be examining topical issues in emissions, exposure and dispersion modelling.
Keynote presentation given by Gyda Grendstad of the Norwegian Public Road Administration at the 2010 CABE Urban Design Summer School in Birmingham, UK.
Similar to Vehicle - Road Interaction, Granlund WSP, NVF Via Nordica 2016 Trondheim (20)
A new method for testing pavement condition combines laser/inertial profilometry of unloaded pavement with vibration measurements in a full loaded heavy truck at highway speed. Three types of results are obtained.
1: Truck wheel, frame and cab vibration, as well as driver seat vibration to be compared with exposure guidelines in ISO 2631-1 and limits in directive 2002/44/EC.
2: Three-dimensional road surface geometry data for simulation of ride and calculation of roughness indices.
3: Locations of potential pavement "soft spots". The latter is possible since large pavement deflection variance under the heavy truck cause a quite different vehicle vibration pattern than the pattern excited from the measured unloaded road surface profile.
A tentative accuracy experiment has been done. Recorded seat vibration levels were very high, thus exceeding the EU Action Value in all test runs. The soft spot indications show reasonable repeatability, as well as reproducibility between different driving speeds and between spring time and autumn. Trueness is the most difficult accuracy feature to estimate, since no ideal reference method is at hand neither for variance of local deflection under truck wheel, nor for global deflection under the entire truck. By comparison with FWD, coring and ground penetrating radar results, trueness seems promising. During the tests, a virtual tyre footprint sensor was used for road profiling. Evaluation showed it to bring a large improvement to profiling accuracy. The new high speed measurement method brings excellent opportunities for further research on the entire chain pavement-truck-ride quality interaction.
Accurate Measurement of Runway Pavement GeometriesJohan Granlund
Paper presented at the Airfield Ad-hoc Working Group Meeting, arranged as a satellite conference during the 23rd PIARC World Road Congress held in Paris, France, 2007.
Bildspel från föredrag inom Vecturas ledarutveckling.
Målet var att föra fram organisationen mot ännu bättre resultat.
Innehåll:
• Ledarskapsteorin ”Utvecklande Ledarskap”.
• Att leda i framtidens samhälle.
• Tre ledarstilar i korthet.
• Att skapa positiva känslor.
• Utvecklande beteenden.
Geometrisk vägbeläggningsprojektering inför mötesfri landsvägJohan Granlund
Geometrisk projektering och datorstödd maskinstyrning vid underhåll eller ombyggnad av vägbanans beläggning skapar en rad nyttor:
* Förbättrad färdkvalitet för trafikanterna.
* Minskad risk för trafikolyckor.
* Minskad risk under ambulanstransporter (ca 1500 avlidna/år).
* Minskad förbrukning av vägsalt.
* Bättre produktionsplanering och ekonomistyrning för vägprojekt.
* Minskade kostnader för framtida underhåll av vägbana och vägräcken.
Uppsats från Vägverkets konferens om mötesfria vägar med växelvis omkörningsfält och mittbarriär, så kallade 2+1 vägar.
Vägnära häckar, buskar, träd och annan växtlighet i BäsnaJohan Granlund
Information om vägföreningens respektive fastighetsägares ansvar:
Säker och framkomlig trafik på bostadsgator kräver fri sikt. Varje år skadas människor i onödan för att sikten skyms. Du som har en häck, träd, mur eller staket mot en gata måste se till att sikten är fri. Några enkla åtgärder före och under sommaren kan rädda liv.
Kan jämnhetsstandarden hos det svenska vägnätet förorsaka fordonsskador och o...Johan Granlund
Johans kommentarer till rubricerat VTI Notat 21-1998:
I VTI notat 21-1998 dras slutsatsen att ”det svenska vägnätet är av så god jämnhetsstandard att av bristande jämnhet förorsakat fordonsslitage och / eller skador bör vara av tämligen marginell betydelse, sett i relation till de totala fordonskostnaderna”. Slutsatsen baseras på studier utförda utan hänsyn till andra brottmekanismer än utmattning, utan inverkan av kallt klimat, utifrån påkänningsmätningar i fordon som avviker stort från vanliga svenska lastbilsekipage (totalviktsskillnader på ca 2200 % mellan mätningens sportbil och en vanlig, lagligt lastad, svensk 4-axlad tung släpvagn), samt utan hänsyn till att Vägverkets rutinmässiga vägytemätningar, vilka avser mindre än en femtedel av det svenska vägnätet, har bruksvillkoret ”otjälad vägbana”. Nämnda bruksvillkor medför en snedvriden bild av ens det statliga belagda vägnätets tillstånd sett över hela året. Enligt här redovisad översiktlig verksamhetsuppföljning hos svenska aktörer inom transportnäringen, medför vägojämnheter på svenska vägar sannolikt mycket stora merkostnader för slitage och skador. I vissa fall medför vägojämnheterna att speditörer vägrar utföra transporter, vilket utgör ett hot mot näringsliv i glesbygd och ytterst mot landets tillväxt. Merkostnaderna för skador och slitage kan sannolikt motsvara en betydande andel av annuiteten av kostnaderna för ett vanligt underhållsprojekt. Transportörernas merkostnader härrör från skador som fjäderstocksbrott, axelbrott, rambrott (!) och liknande, samt från slitage av däck, bromsbelägg, draganordningar mm, samt indirekta kostnader. Fortsatt forskning förefaller ha hög nyttopotential och bör inriktas på monetär kvantifiering av merkostnader för tung trafik pga tjälrelaterade ojämnheter, trumslag och kanthäng. Refererad slutsats i VTI notat 21-1998 framstår som felaktigt underbyggd, och notatet i helhet som starkt vilseledande.
Bildspel från redovisning av hastighetsmätning med radar på länsvägen förbi skolan i Bäsna by (Gagnefs kommun, Dalarnas län), med dess dagis, förskoleklass samt lågstadium klass 1 - 3.
Hastighetsmätning utförd år 2006.
Bildspel från mitt föredrag vid Load Up North i Umeå, 2019.
Exempel på allvarliga fel och brister i Trafikverkets däckrapport:
• Ingen hänsyn till risk för livsfarliga vältolyckor.
• Vägslitage beräknat för irrelevanta lastfall 50 á 60 kN på standard 385 mm breddäck, dvs olaglig överlast.
• Ingen hänsyn till minskad dynamisk vägbelastning.
• Missat att högkapacitetsfordon ger sänkt axellast på alla vägar, inkl. BK4, och radikalt minskat vägslitage i synnerhet på de 4300 km svagaste vägarna (BK2 & BK3).
• Däckrapporten saknar uppdelning av hur kostnad för vägunderhåll påverkas av trafiklast respektive klimat, byggfel mm. Enligt Vägverket (2000) vållas inte mer än 1/4
av kostnaden av trafiklast.
• Helt orealistiskt överdriven uppskattning av vägunderhållskostnad från trafik.
Ansvarsfull hänsyn inkluderar att se möjligheter, snarare än överdriva problem.
Samhället vinner på att låta åkaren välja däckkonfiguration.
Polisen saknar lagrum att bötfälla åkare som kör med enkelmontage på väg där TRV kräver dubbelmontage.
Minska vältrisken vid körning med hög tyngdpunkt, VETA GranlundJohan Granlund
Bildspel från föredrag vid Mittia Skogstransportmässa 2019.
Innehåll:
Fokus på de livsfarliga vältolyckorna.
Video om förebyggande av vältolyckor.
TYA handbok om körning med hög tyngdpunkt.
Haveriutredning av svenskt timmerekipage vid E6 Svinesundparken.
Vägens utformning; i flera fall farliga brister t o m i vägreglerna!
Vägens bärighet; ofta svag vägkant vid vältolyckor med lastbil.
Vägens säkerhetszon.
Bristande vägkvalitet är miljöboven - inte dubbdäckenJohan Granlund
Artikel i Nordsverige om trafikant- och miljönyttor med stålhård porfyr i asfaltslitlager och till dammfri halkstopp. Vid tillverkning av asfalt blandas grus och sand i olika fraktioner med bindemedlet bitumen. Till slitlager på högtrafikerade vägar används sedan länge hård specialsten i asfaltgrusets grövsta fraktion, medan en utbredd praxis är att fingruset och sanden är av ortens svaga bergmaterial. De mindre kornen tål därmed inte slitage från dubbade vinterdäck, medan de grövre kornen tål dubbslitage. Detta gör att redan efter kort tids trafikering så får asfaltens yta i hjulspåren mycket 'rå' textur, medan spårslitaget hålls i schack av det hårda grova grusets stentoppar. Dubbarnas slitage av fingruset ger luftburna partiklar som kan påverka hälsan. Den råa vägytan ger ohälsosamt trafikbuller både i fordon och till vägnära miljöer, samt ökat rullmotstånd och därmed ökad förbrukning av drivmedel (energi) och mer avgasutsläpp så som av växthusgasen koldioxid samt toxiska kväveoxider. Genom att istället i ALLA ballastfraktioner ersätta ortens svaga berg med stålhård porfyr så minskas slitaget av vägytans textur, så att luftkvaliteten hålls uppe.
Tätortsluftens kvalitet hålls också bättre genom att halkbekämpa med halkstopp av stålhård porfyr istället för med vintersand av ortens mjuka gråberg.
Optimalt däckval; dubbel- eller enkelmontage?Johan Granlund
Bildspel från föredrag vid Sveriges Åkeriföretags konferens 'Effektivare transporter' 2019.
Sammanfattning av åkerinäringens granskning av Trafikverkets däckrapport 'Konsekvenser av olika däckskonfigurationer för tunga fordons inverkan på vägnätet'.
Bildspel från föredrag vid Sveriges Åkeriföretags konferens 'Effektivare Transporter' 2019.
Sammanfattning av uppdragsrapport 'Förkortad väglivslängd; orsaker och kostnader', framtagen för den svenska åkerinäringen.
Bildspel från föredrag vid PRO Dalarnas trafiksäkerhetsdag 2019. Den mest typiska dödsolyckan sker i farligt tvär eller nypande, feldoserad kurva på lågtrafikerad länsväg med 50 - 80 km/tim hastighetsgräns och med smala körfält, smal vägren samt brant vägslänt. För att effektivt minska antalet svåra trafikolyckor behövs ökning av drift och underhåll på länsvägarna.
Fallstudie av beläggningsunderhåll på enskilt vägnät, Strategi och taktiskt g...Johan Granlund
Bildspel från föredrag vid förbundsstämma 2019 i Riksförbundet Enskilda Vägar. Bäsna Vägars Samfällighet har beslutat om vision och strategi för beläggningsunderhållet. Föredraget visar hur vägåtgärderna har taktiskt genomförts under sex år; dåliga och goda erfarenheter, samt visar framtiden för vägunderhållet på byns enskilda vägnät.
Lysbilde fra mitt inlegg 'Trafikksikker fremkommelighet' ved Vegsikringskonferansen 2018 i Lillehammer, arransjert av Trafikksikkerhetsforeningen:
* Antall drepte i vegtrafikk øker nå i Sverige; mine teorier om hvorfor.
* Typiske kjennetegn av ulykkessted.
* Sverige vil stoppe vinterfarlige EU-semitrailers med kort trekkvogn.
* «Vinterdekk» på tungbil: Bedre krav enn M+S må innføres.
* Skråkant på veidekke og oppgrusing av skulder sparer liv. Nå införer Sverige skråkant, mens Norge tappet kravet sitt.
* Erfaringer fra trafikkulykker => Bedre normaler & veiadministrasjon.
Förebygg dynamiska laster som deformerar vägbananJohan Granlund
Krönika i Svensk Åkeritidning nr 5 2018, på tema 'Vägen till trafiksäker framkomlighet'. Trafikverket har nu genomfört en utredning om sambandet mellan vägojämnhet och väg-nedbrytning från dynamiska överlaster. Med datormodellering för ett tungt fordon i 100 km/tim visades att svackor och gupp med över 60 m våglängd är skadliga, samt att vägojämnheter med ca 42 m våglängd ger maximal resonans. Redan förbluffande små gropdjup, svåra att se med ögonmått, visades kunna ge så pass stora dynamiska laster att vägbanans livslängd förkortas påtagligt. Uppmätta vägojämnheter på E6, E20 och E45 visades minska vägbanans tjänliga livslängd lokalt upp emot 80 %. Konventionellt beläggningsunderhåll ger liten eller ingen effekt på vägojämnheter med våglängd över ett par meter. Uppföljning av Trafikverkets suveräna demonstrationsprojekt med fläckvis förjustering och datorstyrd planfräsning på Europavägar visar att med den moderna vägtekniken får vägbanan suveränt bra lutningar och jämnhet, samt att vägens nedbrytningstakt blir mångfaldigt lägre. Tillväxten av vägojämnhet visades bli knappt mätbar ens med laserskanning, år efter år efter år efter år efter år. Det handlar om ned till 0.01 mm/m ökad vägojämnhet per år, under flera år efter att underhållsbeläggning utförts.
Comprehensive program for Agricultural Finance, the Automotive Sector, and Empowerment . We will define the full scope and provide a detailed two-week plan for identifying strategic partners in each area within Limpopo, including target areas.:
1. Agricultural : Supporting Primary and Secondary Agriculture
• Scope: Provide support solutions to enhance agricultural productivity and sustainability.
• Target Areas: Polokwane, Tzaneen, Thohoyandou, Makhado, and Giyani.
2. Automotive Sector: Partnerships with Mechanics and Panel Beater Shops
• Scope: Develop collaborations with automotive service providers to improve service quality and business operations.
• Target Areas: Polokwane, Lephalale, Mokopane, Phalaborwa, and Bela-Bela.
3. Empowerment : Focusing on Women Empowerment
• Scope: Provide business support support and training to women-owned businesses, promoting economic inclusion.
• Target Areas: Polokwane, Thohoyandou, Musina, Burgersfort, and Louis Trichardt.
We will also prioritize Industrial Economic Zone areas and their priorities.
Sign up on https://profilesmes.online/welcome/
To be eligible:
1. You must have a registered business and operate in Limpopo
2. Generate revenue
3. Sectors : Agriculture ( primary and secondary) and Automative
Women and Youth are encouraged to apply even if you don't fall in those sectors.
Core technology of Hyundai Motor Group's EV platform 'E-GMP'Hyundai Motor Group
What’s the force behind Hyundai Motor Group's EV performance and quality?
Maximized driving performance and quick charging time through high-density battery pack and fast charging technology and applicable to various vehicle types!
Discover more about Hyundai Motor Group’s EV platform ‘E-GMP’!
Why Is Your BMW X3 Hood Not Responding To Release CommandsDart Auto
Experiencing difficulty opening your BMW X3's hood? This guide explores potential issues like mechanical obstruction, hood release mechanism failure, electrical problems, and emergency release malfunctions. Troubleshooting tips include basic checks, clearing obstructions, applying pressure, and using the emergency release.
Symptoms like intermittent starting and key recognition errors signal potential problems with your Mercedes’ EIS. Use diagnostic steps like error code checks and spare key tests. Professional diagnosis and solutions like EIS replacement ensure safe driving. Consult a qualified technician for accurate diagnosis and repair.
𝘼𝙣𝙩𝙞𝙦𝙪𝙚 𝙋𝙡𝙖𝙨𝙩𝙞𝙘 𝙏𝙧𝙖𝙙𝙚𝙧𝙨 𝙞𝙨 𝙫𝙚𝙧𝙮 𝙛𝙖𝙢𝙤𝙪𝙨 𝙛𝙤𝙧 𝙢𝙖𝙣𝙪𝙛𝙖𝙘𝙩𝙪𝙧𝙞𝙣𝙜 𝙩𝙝𝙚𝙞𝙧 𝙥𝙧𝙤𝙙𝙪𝙘𝙩𝙨. 𝙒𝙚 𝙝𝙖𝙫𝙚 𝙖𝙡𝙡 𝙩𝙝𝙚 𝙥𝙡𝙖𝙨𝙩𝙞𝙘 𝙜𝙧𝙖𝙣𝙪𝙡𝙚𝙨 𝙪𝙨𝙚𝙙 𝙞𝙣 𝙖𝙪𝙩𝙤𝙢𝙤𝙩𝙞𝙫𝙚 𝙖𝙣𝙙 𝙖𝙪𝙩𝙤 𝙥𝙖𝙧𝙩𝙨 𝙖𝙣𝙙 𝙖𝙡𝙡 𝙩𝙝𝙚 𝙛𝙖𝙢𝙤𝙪𝙨 𝙘𝙤𝙢𝙥𝙖𝙣𝙞𝙚𝙨 𝙗𝙪𝙮 𝙩𝙝𝙚 𝙜𝙧𝙖𝙣𝙪𝙡𝙚𝙨 𝙛𝙧𝙤𝙢 𝙪𝙨.
Over the 10 years, we have gained a strong foothold in the market due to our range's high quality, competitive prices, and time-lined delivery schedules.
What Does the Active Steering Malfunction Warning Mean for Your BMWTanner Motors
Discover the reasons why your BMW’s Active Steering malfunction warning might come on. From electrical glitches to mechanical failures and software anomalies, addressing these promptly with professional inspection and maintenance ensures continued safety and performance on the road, maintaining the integrity of your driving experience.
What Does the PARKTRONIC Inoperative, See Owner's Manual Message Mean for You...Autohaus Service and Sales
Learn what "PARKTRONIC Inoperative, See Owner's Manual" means for your Mercedes-Benz. This message indicates a malfunction in the parking assistance system, potentially due to sensor issues or electrical faults. Prompt attention is crucial to ensure safety and functionality. Follow steps outlined for diagnosis and repair in the owner's manual.
In this presentation, we have discussed a very important feature of BMW X5 cars… the Comfort Access. Things that can significantly limit its functionality. And things that you can try to restore the functionality of such a convenient feature of your vehicle.
5 Warning Signs Your BMW's Intelligent Battery Sensor Needs AttentionBertini's German Motors
IBS monitors and manages your BMW’s battery performance. If it malfunctions, you will have to deal with an array of electrical issues in your vehicle. Recognize warning signs like dimming headlights, frequent battery replacements, and electrical malfunctions to address potential IBS issues promptly.
"Trans Failsafe Prog" on your BMW X5 indicates potential transmission issues requiring immediate action. This safety feature activates in response to abnormalities like low fluid levels, leaks, faulty sensors, electrical or mechanical failures, and overheating.
Things to remember while upgrading the brakes of your carjennifermiller8137
Upgrading the brakes of your car? Keep these things in mind before doing so. Additionally, start using an OBD 2 GPS tracker so that you never miss a vehicle maintenance appointment. On top of this, a car GPS tracker will also let you master good driving habits that will let you increase the operational life of your car’s brakes.
What Exactly Is The Common Rail Direct Injection System & How Does It WorkMotor Cars International
Learn about Common Rail Direct Injection (CRDi) - the revolutionary technology that has made diesel engines more efficient. Explore its workings, advantages like enhanced fuel efficiency and increased power output, along with drawbacks such as complexity and higher initial cost. Compare CRDi with traditional diesel engines and discover why it's the preferred choice for modern engines.
2. Overview
Traffic safety risks with EU-semitrailers on slippery roads.
Safety gains for heavy trailers from increased crossfall in road curves.
C/B-analysis: Increasing crossfall is profitable.
Wide shoulder: Effective “barrier” to crashes.
Sweden implementing new pavement condition parameter in 2016.
Improved heavy vehicle safety by increased lane widening in curves.
Road wear from heavy vehicles.
Cutting fuel consumption tenfold per cents, by repair of road damages.
Via Nordica 2016: Vehicle - Road Interaction
3. -Traffic safety risks with
EU-semitrailers on slippery roads
Jamming upgrades.
Jackknife & trailer swing crashes.
Loss of control due to 5´th wheel lock-up at junction in curve.
-Efficient road maintenance reduce the problems!
Via Nordica 2016: Vehicle - Road Interaction
5. Bogie axle lift prevents jammed upgrades
1929: First Volvo with bogie was LV64 Long-Frame.
WWII: Zeta-lyften increased maneuverability.
Bogie axle lift in use for increased hill climbing
performance on icy Nordic roads since 70 years.
No report on axle lift causing pavement damages at
icy stiff-frozen upgrades.
Conclusion: Minimize jamming upgrades, by stipulating
bogie-axle tractor units for EU-semitrailers on Nordic roads.
Future risk:
-Climate change results in icy surface, despite non-frozen road?
Solution to prevent road damages:
-When resurfacing roads, add extra bearing
capacity (thicker asphalt, etc.) at severe upgrades.
Via Nordica 2016: Vehicle - Road Interaction
6. EU-semitrailer crash type 1: The jackknife
Solution:
Redesign of road surface slopes.
Slopes giving acceptable runoff,
with minimal need for filling and
asphalt milling, are Computer Aided
Designed in 3D.
After the adjustment, a new wearing
course is paved on correct slopes.
Via Nordica 2016: Vehicle - Road Interaction
YouTube-video “Amazing car driver avoids collision with oncoming lorry“
At rainfall, the water film is thickest at
crossfall transition sections with low
hilliness and thus low drainage gradient.
These outer-curve sections give
dramatic drops in hydroplaning speed.
A wide “pool” allows the vehicle to
rotate much, before recovering grip.
7. EU-semitrailer crash type 2: Trailer swing
Example: Collision on Hw 50 at Mogetorp (Örebro/Nora)
One died and three were injured when
the EU-semitrailer swung at the slippery
Hw 50.
The 5th wheel had high friction.
The plate around kingpin showed traces of
wear in naked metal, instead of an even
layer of winter-grease.
Photo: B. Eklund
Solutions:
-Increased road friction by ploughing & gritting.
-Reduced 5th wheel friction by proper use of
winter grease.
Via Nordica 2016: Vehicle - Road Interaction
8. Photo: Per Thomson
Junction in horizontal curve:
Slope variance cause 5´th wheel lock-up (1)
Via Nordica 2016: Vehicle - Road Interaction
9. Skid crash at low speed, as the rig started from stop and turned left.
Photo: Trafikverket PMSv3
Photo: Corren
Junction in horizontal curve:
Slope variance cause 5´th wheel lock-up (2)
Via Nordica 2016: Vehicle - Road Interaction
6.6 % crossfall in the junction.
This exceeds the limit max of 5.5 %
for tight curves with high speed.
Solutions:
Move junction from the curve?
Carefully redesign the crossfall!
10. NVF Vehicles and Transport seminar
Traffic safety risks with EU-semitrailers on slippery roads
Held in Karlstad, Sweden, Nov 11th 2015.
Attendees from Norway, Sweden, Finland, Denmark, Pharoe Islands
& Germany.
Data showed that EU-semitrailers with short tractor units are up to
300 % more dangerous, than longer Scandinavian heavy vehicles on
the more hazardous slippery Northern roads.
Summary of the seminar is available at NVF website:
http://www.nvfnorden.org/hemsida/utvalg/ts-risker-med-eu-trailer-pa-hala-
vagar/
Via Nordica 2016: Vehicle - Road Interaction
11. Vision Zero requires focus on the rollover crashes
Via Nordica 2016: Vehicle - Road Interaction
Less than 5 % of the heavy goods vehicle crashes are rollovers.
Photo: Volvo Trucks
Data source: Volvo crash
investigation commission
Crashes with severely injured truck
occupants. n = 1500
Data source:
Rollover of Heavy Commercial Vehicles, UMTRI
Percentage rollovers and injury severity among drivers of
semitrailer rigs in USA; 5 years data.
But…
-Rollover is the crash mode where most truck drivers/passengers
are severely injured!
There are annually about 650 rollovers among heavy trucks
with Swedish license plates; almost two per day.
12. Certain semitrailers are especially sensitive
to adverse cambered curves
Foto: CVDC
De Pont & Milliken, HVTT6
A high center-of-gravity gives rollover-prone vehicles.
Winkler (2000) notes that the most vulnerable are among 5-axle semi-trailer rigs,
loaded to the maximum weight of goods with low density.
These show Static Rollover Threshold (SRT) down to only 0.25.
More recently developed rigs with double floors may be even worse,
when heavily loaded on the upper floor and unloaded on the lower floor.
Via Nordica 2016: Vehicle - Road Interaction
13. Influence of CoG & split friction
Road design codes world wide are based on improper analysis of comfort and skid
risk in low passenger car on pavement with homogeneous friction.
Granlund, Haakanes & Ibrahim (HVTT13, 2014) analyzed risk for both skidding and
rollover with heavy vehicles and on split friction road surface:
Rollover risk in narrow ramps and roundabouts, unless proper crossfall.
Rollover risk in adverse cambered curves.
Substantial increase in skid risk as heavy vehicle rolls sideways.
More hazardous with lower road friction in the outer wheel path.
Photo:VolvoLastvagnar
Figure: Trafikverket
Typically, the center of gravity height and lateral position (load
distribution, too weak lashing, weight transfer) in the trailer and
rearward amplification are crucial for the rollover risk.
Via Nordica 2016: Vehicle - Road Interaction
14. The timber trailer rollover at E6
The Accident Investigation Board Norway contracted
WSP/Advantia for:
Evaluation of road design codes (SE, NO) for ramps.
Laser scanning of road geometry and road condition.
Evaluation of the vehicle and reconstruction of the
crash, by use of a TruckSim model of the vehicle.
Via Nordica 2016: Vehicle - Road Interaction
Foto: Stein Johnsen
Several issues with the road design codes were identified.
The investigated ramp had poor geometry:
steep downgrade,
sharp radius, and
improper crossfall.
The truck had Static Rollover Threshold (SRT) 0.46 g and the trailer 0.40 g;
better than the SRT Minimum 0.35 g limit used in Australia.
15. The timber trailer rollover at E6 (2)
This WSP/Advantia animation shows reconstruction of the rollover at
the trucks recorded speed profile.
The truck top speed in the crash ramp was 49 km/h.
Via Nordica 2016: Vehicle - Road Interaction
16. The timber trailer rollover at E6 (3)
The vehicle combination´s max safe speed in the E6 ramp was calculated by increasing
speed, from low until reaching Load Transfer Ratio = 0.60 at the trailers rear wheels.
LTR 0.60 means that 60 % of the static weight on the inner wheel is dynamically
transferred to the outer wheel. LTR = 1 means wheel lift and eventually rollover.
Max safe speed was determined to 33 km/h; far below the speed limit in the E6 ramp.
This WSP/Advantia animation shows a drive at the max safe speed 33 km/h.
Via Nordica 2016: Vehicle - Road Interaction
17. The timber trailer rollover at E6 (4)
Via Nordica 2016: Vehicle - Road Interaction
18. Upcoming requirements for increased superelevation
Swedish Transport Agency is setting up new safety
requirements for roads and streets.
WSP investigated requirements to "minimize roll risk in
curves" and how much larger superelevation that is
needed:
The crash rate increases by 4 % for each percentage
too little superelevation.
For roads with speed limit less than 90 km/h, the
relevant criterion in the design of superelevation is
stability of unfavorably loaded heavy trailers on dry
asphalt (rollover) and on icy split friction (skidding).
Current maximum allowed superelevation in Sweden
is only 5.5 %. This limit should be raised
significantly. For curves at grades, up to 12 %
superelevation is recommended.
Via Nordica 2016: Vehicle - Road Interaction
19. Exaggerated cost for increasing the superelevation
Via Nordica 2016: Vehicle - Road Interaction
Costs were investigated for increasing superelevation, when
resurfacing old roads. Two reports from NTNU, Bogdashova
(2012) and Lofthaug (2012), were found calculating with
sevenfold too high costs on old roads; 3000 kr/m2.
In comparison; the E4 freeway Uppsala - Mehedeby,
including several bridges and intersections, was
constructed at a total cost of 1923 kr/m2.
WSP investigated costs of increasing
superelevation in numerous scenarios for
existing geometries and for target
geometries with up to 8 % crossfall.
Using data from real world road contracts,
an average cost estimate of 400 kr/m2 was
established for increasing superelevation
when resurfacing old roads.
20. Highly profitable to increase superelevation
Via Nordica 2016: Vehicle - Road Interaction
The profitability for increasing superelevation was calculated by
comparing road agency costs with societal savings for reduction of
vehicle crashes.
The results show high Net Present Value also at low traffic volumes.
21. Analyzing the need for increased superelevation (1)
Via Nordica 2016: Vehicle - Road Interaction
Two firefighters died and
three firefighters were
injured in the hazardous
curve.
Foto: DT / J Svedgård
Data from a laser/inertial Profilometer show the outer curve is adverse
cambered.
Graphical analysis show that outer lane should be banked up from - 1.3
% camber to about + 4 a 6 % superelevation. The outer edge needs to
be raised at least 15 cm.
22. Analyzing the need for increased superelevation (2)
Via Nordica 2016: Vehicle - Road Interaction
Calculate the demand for side friction, fs, by using the
formula for balanced side forces “rearwards”.
The Profilometer provides values for radius R of horizontal
curvature and superelevation tan().
Reference speed = Speed limit, converted into SI-unit [m/s].
)tan
2
(α
R*g
ν
fs
Plot the demand for side
friction along the road.
Compare with design road
friction value; a function of
speed limit, given in road
design codes.
This calculation method can
be used for efficient
analysis of entire national
road networks.
23. Wide shoulder: Effective “barrier” to crashes
Wide road shoulders prevent pavement edge deformation.
Deformed pavement edge cause vehicle lateral buffeting.
Lateral buffeting cause instability crashes.
Via Nordica 2016: Vehicle - Road Interaction
Lateral buffeting is extremely hazardous on ice-slippery roads,
as it can trigger vehicle (or driver) to develop a skid.
Photo: Johan Granlund
24. Wide road shoulders prevent edge deformation
Roads without wide shoulders have regularly
uneven deformations at the pavement edge.
NVF report 04/2012:
An analytical model based on proven
geotechnical method (Terzaghi & Vesic).
0.25 m narrow shoulder can deduct bearing
capacity at the edge to only 45 % of the B.C.
at the road's center line.
Contact pressure during twin 295/60 R22.5
tires, as per COST 334.
Foto: J Granlund
Via Nordica 2016: Vehicle - Road Interaction
25. Lateral support increase edge bearing capacity
Key parameters:
Shoulder width.
Slope towards ditch.
Depth of ditch /
Embankment.
Pavement bearing capacity
(at the road center).
Wide shoulder provides lateral support.
No pavement edge deformation
Access road provides lateral support:
No pavement edge deformation.
Compare with the 7 cm deep depression just in front
of the access road (Note exploded truck tyre).Photo: J Granlund
Photo: J Granlund
Via Nordica 2016: Vehicle - Road Interaction
26. About 25 % of heavy vehicle rollover crashes occur at sections with
deformed pavement edge. De Pont & Milliken (2005).
Edge deformation contribute to crashes
The graph shows sum of vertical loads on all
wheels on the right side of a semitrailer rig, which
runs over a deformed pavement edge.
In this case, edge deformation gave +/- 70 %
dynamic loading.
Pavement edge deformations means slope variance that can provide
lock-up effect in semitrailer 5th wheel => increased crash risk.
Via Nordica 2016: Vehicle - Road Interaction
27. Sweden implements Cross Slope Variance parameter
The “Rut Bottom Cross Slope Variance” parameter validated:
RBCSV correlates with roll vibration in vehicles.
High RBCSV at many crash sites.
High RBCSV in sections reported by truck driver panel as hazardous.
On smooth roads, RBCSV is below limit value “Max 0.3 per cent”.
Foto: J Granlund
Via Nordica 2016: Vehicle - Road Interaction
28. Photo: M Pettersson, NCC, 2015-11-09.
Repair of edge slope variance
Via Nordica 2016: Vehicle - Road Interaction
29. Insufficient lane widening in curve design codes
Sources: FHWA, Teknologisk
Institutt, Statens vegvesen,
Trafikverket
With winter tires on icy road surfaces, the trailer off-tracking is up to
twice, compared to summer conditions.
Nordic curve design codes are valid only for summer conditions.
New curves need double lane widening, compared to current designs.
Many old roads have no lane widening at all!
Via Nordica 2016: Vehicle - Road Interaction
30. Cutting fuel consumption by road repair
The Transmit study (2002) indicated up to 40 % increased truck fuel
consumption on paved state roads in bad condition, than on good roads.
On bad roads, truck speed was lower on average but had higher variance.
Speed variance means braking and (energy consuming) acceleration.
Svenson & Fjeld (2012, 2014, 2016) are analyzing the impact of road
properties on truck fuel consumption, much due to braking/acceleration.
Results show most preventable fuel consumption is caused by:
1. Road damages (road roughness).
2. Road class.
3. Horizontal curvature (also influencing sight distance).
4. Vertical curvature (energy recovered at downhills).
Conclusion:
-Repair of road roughness can reduce fuel consumption, by up to tenfold
per cents.
Via Nordica 2016: Vehicle - Road Interaction
31. Summary
Traffic safety risks with EU-semitrailers on slippery roads.
Safety gains for heavy trailers due to increased crossfall in road curves.
C/B-analysis: Increasing crossfall is profitable.
Wide shoulder: Effective “barrier” to crashes.
Sweden implementing new pavement condition parameter in 2016.
Improved heavy vehicle safety by increased lane widening in curves.
Road wear from heavy vehicles.
Cutting fuel consumption tenfold per cents, by repair of road damages.
Via Nordica 2016: Vehicle - Road Interaction
32. Thank you for your interest!
Via Nordica 2016: Vehicle - Road Interaction