Roadside Safety

Improving road safety has been the key objective for road authorities worldwide for the last years. Lately, many concepts were adopted to reduce the number of fatalities, concepts like self-explaining roads, low cost measures or forgiving roads. As new research findings are published, differing theories evolve and road safety visions change. Nowadays, around 30% of accidents on the entire EU road network are caused by inadequate infrastructure. The way roads are laid out and designed can reduce the exposure to traffic of vulnerable road users, reduce the probability that crash and injury occur when these users are exposed and reduce the severity of injury if it occurs. Substantial and sustainable casualty reductions can be achieved in relatively short time and at relatively short cost by identifying and treating high risk infrastructure sites, creating safer and forgiving roads. The aim of this paper is to improve traffic safety by increasing the awareness of road authorities, in order for them to implement road safety measures following the concepts of forgiving roadsides and taking into consideration the human factors also.

Texas Transportation Institute (TTI) researchers performed an extensive literature review of bridge railing transitions crash tested to Manual for Assessing Safety Hardware (MASH) TL-3, and incorporated the information obtained from this review into the design and details for the new transition testing developed for this project. TTI researchers developed concepts for the new transition anchored to a concrete wing wall. TTI researchers developed a full-scale, three-dimensional finite element model of the guardrail transition. The modeling effort included developing and validating a subcomponent level model of the post installed on concrete. Upon completion of the simulations, TTI researchers processed the results and assessed the likelihood of the transition system passing the required MASH crash tests. TTI researchers noted the design deficiencies and recommended design modifications to the system to mitigate those deficiencies. TTI researchers developed full-scale test installation drawings of the design after the finite element model simulations were completed and all the results were reviewed with favorable results. After approval of the test installation drawings by Texas Department of Transportation (TxDOT), construction of a full-scale test installation for crash testing commenced, and crash tests were performed on the full-scale test installation. The Guardrail to Rigid Barrier Transition Attached to Bridge or Culvert Structure, used on the upstream and downstream ends, performed acceptably for MASH TL-3 transitions.

The use of toll roads has risen dramatically in many countries around the world. Although toll roads offer a high level of service, and in general they are well-maintained roadways, there is a lack of research that quantifies the safety impacts of using different toll collection systems. This study examines the traffic safety impact of using different designs of the Hybrid Mainline Toll Plaza (HMTP). HMTP are plazas that combines open road tolling for Electronic Toll Collection (ETC) and plaza structure for manual payment. Also, this study helps understand the relationship between the crash frequency and several important crash-related factors and circumstances.
Crash data from a seven-year period was investigated, and a hundred mainline toll plazas in Florida were evaluated. The analysis was conducted using Negative Binomial and Log-Linear models.
The results of this study proved that there is a significant difference between the different designs of the HMTP. And there is an indication that the majority of crashes occurred at diverge-and-merge areas before and after the plaza. Moreover, the results indicated significant relationships between the crash frequency and toll plaza types, annual average daily traffic, and driver-age. This study has also proved that the HMTP and the All-Electronic Toll Collection were associated with less number of crashes than the traditional mainline toll plazas by 44.7 and 72.6 percent, respectively. For those countries who cannot adopt the HMTP and AETC systems, improving traffic safety at traditional mainline toll plazas should take a priority.

An efficient management system and leadership body is one of the key requirements for a road safety improvement program. In low-and middle-income countries, the organizational structure of the management system may suffer from deficiencies weakening the institutional functions across key road safety players. Hence, it is necessary to form an inner-and inter-organization evaluation framework encompassing all the processes, events, dependencies, and causation among road safety players. In this paper, a (three-stage) system thinking approach is developed to evaluate the behavior of inter-organizational complex system and to determine major deficiencies in the role of the road safety lead agency. The first stages of the system thinking approach starts with drawing diagrams (i.e. multiple-effect and multiple-criteria trees) that allows identifying the chains of reasoning behind events or consequences. The next stage of the system thinking approach embodies the analytic network process (ANP), an advanced multi-criteria decision-making technique, which handles the lead agency capacity evaluation and helps to determine how and by what magnitude any of the players can affect the national road safety. The proposed method applies to the case of Iran, a middle-income developing country in the Middle East. Since in Iran, the Road Safety Commission (RSC) has been established as the lead agency, it was expected that RSC owns the greatest influence on the status of road safety. However, our results show that the overall influence of RSC on road safety is far less than what was expected. Subsequently, a supplementary procedure is proposed to specify institutional reforms in order to avoid such organizational inefficiencies.

This publication highlights a few examples of GRSF’s effective delivery of global road safety solutions for the period of 2017-2019. From reducing road crash deaths and injuries in Ho Chi Min City to increasing road safety investments in Addis Ababa – the report summarizes lessons and results from multiple country contexts.

Road safety interventions carried out in Colombia, Ethiopia, Nepal, Morocco, Bolivia, Togo, China and Thailand present opportunities for expanding this work to other client countries.

Abstract— Levels of nitrogen dioxide and sulphur dioxide around roadside gardens in Port Harcourt metropolis were determined at 0m and 50m from road junctions using portable hand held Multi RAE PLUS (PGM-50), a programmable multi gas monitor with an electrochemical sensor for the detection of Sulphur dioxide and ITX Multi Gas monitor for the detection of Nitrogen dioxide. The results showed that the concentrations of NO2 and SO2 ranged from 0 – 0.3ppm in both seasons. The mean concentration of SO2 at 0m and high traffic density stations were higher than the mean concentration at 50m and low traffic density stations. The difference in mean concentrations between dry and rainy seasons, traffic density and distance were not significant for NO2 but significant for SO2. The concentration of NO2 and SO2 recorded at the study stations exceeded the permissible limits of 0.004ppm and 0.01ppm respectively, recommended by the Federal Ministry of Environment and therefore poses serious threat to the environment particularly small farms and gardens around major roads. The levels of NO2 and SO2 around the gardens were influenced by traffic density, seasonal variations and distances from major roads, therefore authorities should embark on sensitization and enlightenment campaigns; farming activities and raw consumption of exposed vegetables, crops and fruits should be discouraged in the study areas.

Traditional mainline toll plaza (TMTP) is considered the most high risk locations on the toll roads. Conversion from TMTP or Hybrid Mainline Toll Plaza (HMTP) to an All-Electronic Toll Collection (AETC) system has demonstrated measured improvements in traffic operations and environmental issues. However, there is a lack of research that quantifies the safety impacts of these new tolling systems. This study evaluated the safety effectiveness of conversion from TMTP or HMTP to AETC system. An extensive data collection was conducted that included a hundred mainline toll plazas located on more than 750 miles of the toll roads in Florida. Various observational before-after studies including the Empirical Bayes method were applied.
The results indicated that the conversion from the TMTP to an AETC system resulted in an average crash reduction of 77, 76, and 67 percent for total, fatal-and-injury and Property Damage Only (PDO) crashes, respectively; for rear end and Lane Change Related (LCR) crashes the average reductions were 81 and 75 percent. The conversion from HMTP to AETC system enhanced traffic safety by reducing crashes by 23, 29 and 19 percent for total, fatal-and-injury, and PDO crashes; also, for rear end and LCR crashes, the average reductions were 15 and 21 percent, respectively.
Overall, this paper provided an up-to-date safety impact of using different toll collection systems. The results proved that the AETC system significantly improved traffic safety for all crash categories; and changed toll plazas from the highest risk on Expressways to be similar to regular segments.

Groups of in-line piles connected by beams are being used to contain errant vehicles for roadside safety and perimeter protection of sensitive infrastructure. The effectiveness of in-line groups of piles to safely redirect or stop approaching vehicles has not been well-investigated from the geotechnical point of view. In this paper, the performance of barriers is examined through full-scale crash tests and numerical simulations. The full scale crash tests consisted of two different configurations of piles and beams as well as two different soil types: one was in loose sand and the other in hard clay. Both barriers were subjected to vehicle impact: one by a medium-duty truck and the other by a pickup truck. The barriers successfully contained the impacting vehicles. Detailed finite element models of the barriers and the soil were developed and combined with the vehicle models to simulate the dynamic events. Comparison between predicted and measured behavior was used to calibrate the models. Additional simulations were performed to evaluate the effect of major structural and geotechnical design parameters including soil strength, pile spacing and number of piles on the impact response of these systems. Practical recommendations are drawn from the experimental and numerical work.

The need to establish Criteria for Road Lighting has been underlined in recent years, stemming primarily from the demand for ‘safe roads’. While the connection between adequate road lighting and safety in terms both of accident as well as crime prevention is straight-forward, thus allowing for cost/benefit analysis on those terms, it is more complex to establish road lighting criterion based on considerations for aesthetics and amenities. Nevertheless, it has also been established that the latter holds a distinct place among the four major functions of road lighting1.
Aesthetic and amenity considerations are both directly or indirectly related to what can in general be termed as “beautification”. Aesthetics as a noun is concerned with beauty or its appreciation, and has been defined as a set of principles of good taste and/or the appreciation of beauty2. Amenity is concerned with “pleasantness” and has been defined as a useful feature of a place or thing. In this sense amenity considerations therefore encompass aesthetics, while demanding some further qualities of acceptability. Furthermore, amenity considerations involve an added quality of usefulness and practicality to be accounted for. Both words are however abstract enough to defy exact quantification. Architects in their quest to define relationships between aesthetics and form have discoursed long and hard on the subject with no exact or definite solutions3.
The question of whether it is possible to quantify or assess the amenity content in a lighting system on a cost/benefit basis is a very difficult one. Some attempts are being made to give a scientific basis to the extremely subjective notion of ‘aesthetics’4,5, but they are not yet supported by experimental verification, even if such an endeavour may be possible. The purpose of this paper is to touch on points that influence aesthetic and amenity considerations of road lighting so that awareness of its different aspects can be generated.

Platooning is an extension of Cooperative Adaptive Cruise Control (CACC) and forward collision avoidance technology; it allows lateral and longitudinal control of vehicles while they move in tight formations. Platooning is ideal for trucks as they usually travel long distances in highways as a group. It is necessary to understand if the existing roadside safety devices are adequate to resist the consecutive impacts at high speed that can occur due to errant truck platoons. It is also important to analyze the associated occupant risks during such impact events. A detailed analysis of the capacity and adequacy of Manitoba Concrete Bridge Rail using computer simulations, under Manual for Assessing Safety Hardware (MASH) Test Level 5 (TL5) criteria, is presented in this study. The study briefly discusses the methodology to run multiple impact computer simulations in LS-DYNA. The impact of the leading truck is validated using the known data from a full-scale crash test; then, the impact events involving the following trucks are simulated to understand the additional capacity of the roadside barrier. To assess the occupant risk, the flail space model (FSM) concept is utilised as per MASH criteria. Simulation results imply that catastrophic barrier failure and major injuries to the occupants are unlikely to occur during the truck platoon impact.

Qualitatively comparing the shapes of time histories to validate experiments with computational simulations is a common technique in both general computational mechanics as well as computational roadside safety. Qualitative comparisons, however, are subjective and open to interpretation. A variety of quantitative metrics are available for comparing time history data as well but developing acceptance criteria for these methods often relies on equally imprecise engineering judgment. This paper presents the results of time-history comparisons of 10 essentially identical full-scale vehicle re-directional crash tests with a vertical concrete wall. Five of the crash tests used exactly the same type of vehicle whereas the other five used a similar vehicle that was within the EN1317 test vehicle specifications for that class of vehicle. A variety of quantitative shape comparison metrics were calculated for each set of repeated crash test cases and the results are presented. The results are ...

Poles are regularly placed along highways and are used to support signs, lights and electrical lines. The Midwest Guardrail System (MGS) is a standard W-beam guardrail system used throughout the United States to redirect vehicles that leave the roadway away from dangerous roadside obstacles, like ravines, water hazards, and bridge piers. Placing poles near a guardrail may affect its ability to safely contain and redirect vehicles. The compatibility of poles placed in the proximity of the MGS is studied using nonlinear finite element analysis. Computer simulations were conducted with vehicles impacting the MGS with varying lateral pole offsets between the back of the system and the front face of the pole, and varying longitudinal pole location from being placed directly behind a post to directly behind the unsupported rail halfway between posts. Results show that poles placed within 16 inches behind the MGS may cause concern in regard to acceptable crash test performance for guardrail systems. Additional simulations and full-scale crash testing is required before guidelines can be recommended.

ABSTRACT: This paper describes a study of the behavior of a group of piles under
impact loading. Many structures such as bridge piers, offshore platforms or berthing
foundations can be subjected to the horizontal impacts from ships during their
lifetime in which the system failure would have serious consequences. Guardrails for
road side safety are another type of impact resisting system which are extensively
used and have a direct relation with human life and cost. Moreover groups of piles
can serve as an efficient and relatively cost-effective protecting structure around
critical and important facilities. Prediction of the system response during the impact
can lead to a more effective and economical design. There has been a very limited
amount of experimental work on lateral response of group piles under impact loading
in particular in the field of full scale tests. This paper describes a full-scale field test
performed on a group of 8 side by side piles embedded 3m in a loose sand to sustain
an impact of a 6800kg truck with an approaching velocity of 80 km/h. The
instrumentation includes accelerometers on the truck, strain gages on the posts and
high speed cameras to capture the deflection. The eight posts and the connector beam
have been simulated using an advanced numerical simulation software LS-DYNA
(Livermore Software Technology Corporation, 2006) to characterize the features of
the soil-pile-beam interaction under impact and improve the design methodology.

Improving road safety has been the key objective for road authorities worldwide for the last years. Lately, many concepts were adopted to reduce the number of fatalities, concepts like self-explaining roads, low cost measures or forgiving roads. As new research findings are published, differing theories evolve and road safety visions change. Nowadays, around 30% of accidents on the entire European Union (EU) road network are caused by inadequate infrastructure. The way roads are laid out and designed can reduce the exposure to traffic of vulnerable road users, reduce the probability that crash and injury occur when these users are exposed and reduce the severity of injury if it occurs. Substantial and sustainable casualty reductions can be achieved in relatively short time and at relatively short cost by identifying and treating high risk infrastructure sites, creating safer and forgiving roads. The aim of this paper is to improve traffic safety by increasing the awareness of road a...

Risk perception being a very common psychological phenomenon can affect road safety attitude directly as well indirectly. From a theoretical perspective, risk perception is considered a crucial factor in understanding the process of behavioural change. It refers to the subjective interpretation involved in different traffic situations [1]. Brown & Groeger [2] suggested that this perception is determined by information regarding the potential hazards in the traffic environment and information on the ability of the actor to prevent those potential hazards from being transformed into actual accidents. Perception of risk of road accidents by drivers can make them to adopt the behavior that helps in preventing road accidents. Risk perception affects drivers' attitude regarding traffic rules, non-driving activities and driving responsibility [3]. Risk perception can modify human behavior. Risk perception affects drivers' attitude regarding traffic rules, non-driving activities and driving responsibility. Persons who possess high level of risk perception are more likely to be cautious and careful in their behavior. Risk perception helps in adoption of protective behavior. Risk perception is determined by the information of the potential hazards in traffic environment, and on the ability of driver to perceive the potential hazards resulting into actual accidents. There is a significant relationship between risk perception and road accidents [4]. Risk perception significantly indirectly affects the risky driving behavior [5]. Risk perception depends upon driving training, driving experience, age of drivers, etc. Driving training increases risk perception of drivers [6]. The age of driver influences risk perception and risktaking behavior [7]. Ulleberg & Rundmo [8] have shown that risk perception is significantly related to risky driving behavior and risk-taking attitudes. There is a positive correlation between risktaking attitude and risky driving behavior [9]. Risk taking attitude predicts risky driving behavior. Risk taking attitude comprises rule

Many precious lives are lost due to road accidents because of over speeding and negligent driving every day. This is the matter of great concern for departments that deal with road safety and for the citizens. It is estimated that 80% of crashes and 65% of near collisions are due to driver's lack of attention to traffic for three seconds before the event. The number of road crash deaths has increased by 31% from 2007 to 2017. As per the survey on the road accidents in India, according to the Ministry of Road Transport and Highways, 1, 50,785 people were killed and another 4, 94,624 were injured in 4, 80,652 road crashes in India in 2016. Now day's accidents are taking place at large scale. Majority of the accidents occurs due to the over speeding of vehicles, though there are speed limiting boards placed at the roadside of highways also at the road side in the city. But none of vehicles (drivers) follows the speed mentioned in the speed limit boards, due to which accidents occurs.

Although they are widely used in many places, little research has been devoted to examining the acceptability of chain link fence and its impact on driver behavior. A questionnaire survey was therefore undertaken to gather information on the drivers' location or situational preferences, their perceptions of the outcomes, and the effects on their self-reported driving behavior. In addition, surveys on traffic speed were conducted at a number of locations with and without chain link fence. Our results showed that drivers do react to the presence of chain link fence by reducing their driving speed. These results suggest that chain link fence can be used as a traffic calming device, especially in school and playground zones