Inventory of best practices to prevent incursions into work zones : Literature review

The report reviews the literature to identify existing best practices used to prevent incursions into work zones and improve safety of road users and road workers. A systematic literature search was conducted and various available sources referred to by knowledgeable experts in the field were considered. Best practices found in the literature review comprise both regulatory/management issues and technical issues

DYNAMIC SPEED ADAPTATION IN ADVERSE CONDITIONS

This paper proposes a system for dynamic speed adaptation in adverse conditions, such as wet/slippery roads, decreased visibility, darkness and sharp curves. Accident risks increase drastically in such conditions, especially since drivers often do not adapt speeds to lower friction or impaired visibility. Thus, the discussion is centred around a method for calculating the appropriate highest speeds and a system to influence driver’s speed-choice in these conditions via an in-vehicle device. The safety effect of the proposed system is estimated to result in a 19% - 42% reduction of injury accidents in Sweden. The paper concludes by making suggestions for further research into alternative technological solutions, effects on driver behaviour and workload and implementation of the system for other reasons than weather and road-dependent adverse conditions. (Less) Document type: Articl

SPEED REGULATION BY IN-CAR ACTIVE ACCELERATOR PEDAL

The effects on speeds and speed distribution were studied in a large scale field trial with an in car system for speed adaptation in the city of Lund, Sweden. In the trial 290 vehicles were equipped with an "active accelerator pedal" and data logger for a period of 3-11 months. Data was logged in each test vehicle during the whole trial and was analyzed for 3 one-month periods: Before activating the system, after short time use and after long time use. The results showed significant reductions in the speed level. Speeds on stretches decreased statistically significantly (p"0.05) at 60 out of 69 observed sections. The effects were largest on arterial roads, at mid-block sections, where the prevailing traffic conditions and street design allows higher speeds. The standard deviation decreased on all arterial roads, mainly due to the decrease in speed of the fastest vehicles but there is also an effect from an increase in speed of the slowest vehicles. On streets with mixed traffic no differences in speed or speed distribution could be shown. This is most likely due to the fact that speeds were already controlled by the prevailing traffic conditions and they already were so low that the system never had to interfere. Further research is needed in order to investigate possible behavioral adaptation effects when the system is active as well as inactive and how driver behavior would be influenced in a situation where a large part of the vehicle fleet equipped with an active accelerator pedal. (Less) Document type: Articl

SPEED REGULATION BY IN-CAR ACTIVE ACCELERATOR PEDAL

The effects on speeds and speed distribution were studied in a large scale field trial with an in car system for speed adaptation in the city of Lund, Sweden. In the trial 290 vehicles were equipped with an "active accelerator pedal" and data logger for a period of 3-11 months. Data was logged in each test vehicle during the whole trial and was analyzed for 3 one-month periods: Before activating the system, after short time use and after long time use. The results showed significant reductions in the speed level. Speeds on stretches decreased statistically significantly (p"0.05) at 60 out of 69 observed sections. The effects were largest on arterial roads, at mid-block sections, where the prevailing traffic conditions and street design allows higher speeds. The standard deviation decreased on all arterial roads, mainly due to the decrease in speed of the fastest vehicles but there is also an effect from an increase in speed of the slowest vehicles. On streets with mixed traffic no differences in speed or speed distribution could be shown. This is most likely due to the fact that speeds were already controlled by the prevailing traffic conditions and they already were so low that the system never had to interfere. Further research is needed in order to investigate possible behavioral adaptation effects when the system is active as well as inactive and how driver behavior would be influenced in a situation where a large part of the vehicle fleet equipped with an active accelerator pedal. (Less) Document type: Articl

Interaction between Cyclists and Motor Vehicles : the role of infrastructure design and vehicle characteristics

The aim of the project was to examine interactions between motor vehicle drivers and cyclists at intersections and the impact of infrastructure design and motor vehicle characteristics on interactive behaviour. The project activities included literature reviews on cycling infrastructure at intersections, vehicle driver behaviour and cyclist behaviour; questionnaires among motor vehicle drivers and cyclists across different cities in Sweden; field observations to investigate what cues cyclists use to interpret the intention of motor vehicles they interact with at signalised intersections; on-site interviews with cyclists to explore their strategy in an encounter with a motor vehicle; and a cycling simulator study to examine the behaviour of cyclists when approaching an intersection and the factors that may influence their decisions. The findings confirm that the way the cycling infrastructure is designed at intersections contributes to how cyclists and motor vehicles interact. Placing cyclists and motor vehicle drivers close (where they are visible to one another) at intersection areas increases the level of presence-awareness for both road users and consequently it increases safety. Though cyclists may feel more uncomfortable (exposed and unsafe) with this solution, they tend to be more careful and attentive. This finding from the literature was confirmed by the field observations showing that mixed traffic, i.e. “no cycle facility” at the intersection is the safest solution and the cycle lane solution is the least safe one. However, the on-site interviews with cyclists revealed that the large majority of the respondents preferred the infrastructure solution with a separated bicycle path. This is a typical case where objective safety and subjective safety stand in opposite relationship. The findings also revealed that one-directional cycle tracks enhance interaction at intersections, since motor vehicle drivers only expect cyclists from one direction. However, cyclists not following the rule and riding against the prescribed direction create problems and conflictive situations. Cyclists and the way they use the road infrastructure were found to be highly heterogeneous; the availability of cycling infrastructure at an intersection does not guarantee that cyclists use it as expected by designers and perhaps by motor vehicle drivers, as the infrastructure solution in some cases might not provide the shortest path for the cyclist. The uncertainty in cycling behaviour was found to be more at intersections with no cycling infrastructure. Confidence level among cyclists was found to affect their interaction with motor vehicles which tends to be hard for motor vehicle drivers to predict as different cyclists behave differently depending on their confidence in traffic.The majority of the interviewed cyclists said that when arriving at an intersection just after a motor vehicle they usually pass it on its right side. This was seen in observations on sites with cycle lane or cycle path but not on sites with mixed traffic. Also, if the motor vehicle was a heavy vehicle (bus or truck), somewhat fewer cyclists passed it on its right side. Also the cycling simulator study revealed that the most significant difference of longitudinal stop position was between the condition of a narrow lane without cycle lane marking and a truck standing at the stop line and the condition of wide lane with cycle lane marking and a car standing at the stop line, where the average stop position of the cyclist was behind the truck in the first condition and next to the car in the second condition. This finding corresponds to the test cyclists’ verbal expressions of the importance of “being visible and avoiding the blind spot”. The increased caution associated with the presence of a truck is motivated and in line with previous studies. At sites with mixed traffic (no cycle facility), compared to with cycle lane or cycle path, the cyclists’ scanning behaviour was more complete. At sites with cycle path, the cyclists looked for eye contact with the driver of the motor vehicle to a much larger extent than cyclists at the other two types of sites. Cyclists at sites with mixed traffic (no cycle facility) were more active in their visual search behaviour than cyclists at the other two types of sites. Also, those cyclists who passed the motor vehicle on its right side were more active in their visual search behaviour than those who did not pass the motor vehicle. The share of critical situations indicates that sites with mixed traffic (no cycle facility) is the safest solution and cycle lane solution is the least safe one

Inventory of best practices to prevent incursions into work zones - Literature review.

The aim of this report was to review the literature to identify existing best practices used to prevent incursions into work zones and improve safety of road users and road workers. A systematic literature search was conducted and various available sources referred to by knowledgeable experts in the field were considered. Best practices found in the literature review comprise both regulatory/management issues and technical issues

Measuring sustainability of transport in the city - development of an indicator-set

The HASTA indicator framework, covering the three dimensions of sustainability, i.e. Economic, Environmental and Social, to monitor sustainability of transport in Swedish cities was elaborated. Under the three sustainability dimensions, there are 6 sustainability aspects (indicator groups), 2-3 per dimension; these are Efficiency, Accessibility (Economic dimension), Accessibility, Safety, Liveability (Social dimension); Emissions, Resource use (Environmental dimension). The accessibility indicator group is related with both economic and social sustainability. The individual indicators are structured in three levels of a hierarchical structure. The highest level is represented by the Outcome indicators which reflect the sustainability target in the subject area of the indicator. These Outcome indicators are of both objectively measurable variables and subjective variables, reflecting how the inhabitants experience sustainability of transport in their city. On the lowest level, the Input indicators provide information on possible measures to make improvements in transport sustainability. On the intermediate level, the Output indicators show the effect of the adopted measures (Input indicators). There are 19 Outcome indicators, 22 Output indicators and 42 Input indicators

Road Safety Management at Work Zones : Final report

Accidents nearby work zones are a persistent road safety problem in many European countries. The Conference of European Directors of Roads (CEDR) has initiated and finances the IRIS project (Incursion Reduction to Increase Safety in road work zones) with the aim to collect and share information about best practices in temporary traffic management at road works. An analysis of work zone accidents and a review of best practices were made. Psychological issues to improve safety at work zones were studied by a literature review. Interviews with stakeholders were carried out in eight European countries to gather information on guidelines, standards and procedures in temporary traffic management. Best practice findings cover organizational/management issues, work zone safety reviews, establishment/de-establishment of a road work zone, informing/warning and guiding road users through work zone areas, speed management, protecting devices for road workers’ and road users’ safety and incursion warning systems

Road Infrastructure Safety Management : Review of National Design Guidelines and Procedures

As part of the HORIZON EUROPE project AfroSAFE, a review of national regulations, guidelines, and procedures for Road Infrastructure Safety Management (RISM), as well as road design guidelines was carried out in Ghana, Tanzania, and Zambia. Information was collected from relevant authorities and the review had special attention to the safety of vulnerable road users (pedestrians, cyclists, and motorcyclists)