Roadside Crash Research Articles

Roadside Media: Roadside Crash Shrines as Platforms for Communicating Across Time, Space, and Mortality in the Early 2000s United States

ABSTRACT This article argues that since the 1990s, roadside shrines in the United States have become place-bound forms of media that provide multiple publics with platforms for communicating with the dead and for communicating with other platform users about the dead. Evidence that roadside shrines function as media today is accessible even to strangers who witness roadside shrines because people leave visual, material, and spatial traces of these communications at shrine sites themselves. There, you can see that people interact with shrines as if they are platforms for communication – demonstrating elaborately performed ‘continuing bonds’ between mourners and the site, and thus victims, as well as among mourners. Moreover, roadside shrines are today intertwined with the larger convergent media environment, where a shrine site often becomes a material manifestation of other representations of ‘the pervasive dead’ across the media environment. To trace the history of how roadside shrines came to work this way, I relate them to the larger cultural history of media and memorialisation in which they are entangled and then analyse three specific case studies from New Mexico and Texas at the crucial transitional moment in the first two decades of the 2000s when roadside shrines became established as media.

Experimental, analytical, and numerical investigation of multi-chambered fluid-filled barrier for highway crash attenuators

Guardrail end terminals and roadside crash cushions are common technologies deployed to absorb and redirect the energy of a colliding vehicle. The purpose of these devices is to reduce damage to structures and vehicles while limiting the effects these collisions have on motorists. The primary mode of energy absorption of these structures is through physical deformation. This physical deformation can often create hazardous scenarios for vehicle occupants. This paper shows the study of a new (patent pending) crash attenuator composed of a multi-chambered, fluid-filled barrier. Kinetic energy of the colliding vehicle is transferred to the fluid and through the internal structure. As fluid moves through the structure, energy is dissipated through viscous friction; therefore, reducing the peak forces experienced by the vehicle and its occupants and reducing damage to the structure and the vehicle. Experiments were conducted using a mechanical ram to impact a dual-chambered cylindrical plastic container partially filled with water. The impact event was recorded using a high-speed camera and the acceleration impulse was measured using an accelerometer attached to the ram. The results of this study show that the addition of interior chambers and fluid decreased the reaction forces by nearly 50% and a two-fold increase in energy absorbing efficiency as compared to an empty structure. Analytical and numerical approaches were used to assess the energy dissipation due to plastic deformation of the structure. The addition of fluid and internal chamber reduced the plastic deformation of the sample by 9.1% as compared to the empty structure. This confirms the ability of the present structure to maintain low reaction forces while reducing damage to the structure and in turn increasing barrier lifetime. The present barrier technology can potentially replace existing guardrail end terminal and crash cushion systems and due to its small footprint, can be utilized in areas where traditional systems cannot be deployed due to space constraints.

Identifying factors associated with roadside work zone collisions using machine learning techniques

Identifying factors that are associated with the probability of roadside work zone collisions enables decision makers to better assess and control the risk of scheduling a particular maintenance or construction activity by modifying the characteristics of the operation. This can be achieved by studying the effect of work zone properties on the risk of roadside work zone collisions. Much of the existing work in this area is based on data in the police traffic collision reports, which do not include data on the characteristics of the work zone itself. This paper develops a comprehensive data set of 42 features describing time, location, work zone characteristics, traffic volume, and road properties. Using recent machine learning techniques such as extreme gradient boosting classifiers on this extensive set of features allows for more accurate analysis to identify factors that affect the risk of work zone collisions or indicate higher than baseline chances of a roadside crash. Our statistical analysis reveals 10 important features and shows that four of these features are significantly associated with higher probabilities of roadside work zone collisions.

Analysis of Roadside Accident Severity on Rural and Urban Roadways

The differences in traffic accident severity between urban and rural areas have been widely studied, but conclusions are still limited. To explore the factors influencing the occurrence of roadside accidents in urban and rural areas, 3735 roadside traffic accidents from 2017 to 2019 were analyzed. Fourteen variables from the aspects of driver, vehicle, driving environment, and other influencing factors were selected to establish a Bayesian binary logit model of roadside crashes. The deviance information criterion and receiver operating characteristic curve were used to test the goodness of fit for the traffic crash model. The results show that: (1) the Bayesian binary logit regression model well fits the traffic crash data, and the goodness of fit for sub-models based on separate urban and rural data is better than when based on all data (urban and rural); (2) 10 variables have a significant influence on the extent of roadside crash severity in the two areas, with different impacts; (3) drunk driving increases the probabilities of fatal traffic accidents by 10.8% and 16.4% in urban and rural areas, respectively; (4) the probabilities of fatality caused by traffic accidents involving trucks are 4.6% and 9.8% higher than those without trucks in urban and rural areas, respectively. The findings of this study can provide a theoretical foundation for traffic safety administration to formulate relevant policies or strategies in order to reduce the severity of roadside accidents.

Safety evaluation for roadside crashes by vehicle–object collision simulation

In order to evaluate roadside crash severity and help making decision on roadside safety improvement alternatives, this article proposes a roadside crash severity evaluation method based on vehicle kinematics metric during the crash: Acceleration Severity Index. Based on the field investigation on 1917 km of representative roads, roadside crash test standards and parameters were determined. A total of 59 crash scenarios, involving 5 typical roadside obstacles, 2 types of guardrails, 15 embankment slopes, and 3 types of vehicles (car, bus, and truck), were designed for simulated crash testing with VPG3.2 and LS-DYNA971 software. The x-, y-, and z-direction acceleration (or deceleration) curves of a test vehicle’s center of mass during each crash test were collected for the calculation of the Acceleration Severity Index values. The Fisher optimal partition algorithm was used to cluster the Acceleration Severity Index values to identify an appropriate number of roadside crash severity levels and the corresponding threshold values that demarcate these levels. The results showed that the roadside crash severity classification produced by Acceleration Severity Index–based method is consistent with handbook Guideline for Implementation of Highway Safety Enhancement Project. Therefore, when crash data are missing, crash test could be a feasible surrogate method for roadside crash severity evaluation.

Vehicle-to-barrier communication during real-world vehicle crash tests

Vehicle-to-barrier (V2B) communication is expected to facilitate wireless interactions between vehicles and roadside barriers in next-generation intelligent transportation systems. V2B systems will help mitigate single-vehicle, run-off-road crashes, which account for more than 50% of roadside crash fatalities. In this work, the characteristics of the wireless channel prior to and during a crash are analyzed using orthogonal frequency division multiplexing (OFDM) techniques, which has been used in existing vehicular communication systems. More specifically, the performance of OFDM-based V2B links are measured in real-world crash tests for the first time. Three crash tests conducted at the Midwest Roadside Safety Facility, Lincoln, Nebraska, are reported: a bogie vehicle crashing into a soil-embedded post at 27 mph, a sedan crashing to a concrete curb at 15 mph, and a pickup crashing to a steel barrier at 62 mph. Metrics including signal to interference plus noise ratio received signal strength, error vector magnitude, phase error, channel coherence, and bit error rate, are used to illustrate the impacts of antenna type, antenna deployment, speed, and mobility during the crash tests. The empirical evidence shows that barrier-height (0.7–0.9 m) antennas at the barrier can improve V2B signal quality compared to higher deployments (≥1.5 m) due to the stronger reflection of electromagnetic waves at a larger angle of incidence. Moreover, compared to omni-directional barrier antennas, directional barrier antennas can increase signal quality, connectivity, and coherence time of V2B channel because of reduced multi-path effects, however, the antenna orientation needs to be carefully determined to maintain connectivity.

An In-Depth Investigation of Roadside Crashes on Thai National Highways

Road crashes in Thailand cause some 13,000 deaths each year. About 12% of these occur on national highways under the jurisdiction of the Department of Highways (DOH). For the past four years, 2007-2010, roadside crashes have constituted between 42.2 - 47.9 %, averaged 44% of the total crashes on the DOH's highways. This paper presents the result of in-depth roadside crash investigations with the aim of improving the roadside safety situation in Thailand. It was found that speeding was the main human error that contributed to the crashes, accounting for 57% of the causes. The cases involving vehicle hitting trees, the most common roadside hazard in Thailand, were found to be the most serious and common roadside crashes accounting for 72% with resulting 48 fatalities. The paper gives details of the investigation into the cause and consequences of these crashes. The authors urge DOH to take needed actions on the proposed strategies to deal with this immensely serious problem. The strategies are based on the DOH Roadside Safety Strategic Plan 2009-2013.

Analysis of Roadside Safety of Highways in South Thailand

Every year, the number of road crashes in Thailand, which result in about 12,000 deaths, has been around 1 million. About 12% of these crashes occur on national highways under the jurisdiction of the Department of Highways (DOH). For the past four years, 2007- 2010, roadside crashes have constituted between 42.2 - 47.9 % of the total crashes on the DOHA's highways. On average there is about 12000 crashes on Thai national highways and roadside crash accounts 5900 cases or 44%. This paper describes the roadside crash situation on Thai highways by using DOH records of 949 crashes that occurred during 2007-2010 on 270 km. section in Southern Thailand. The results show that speeding vehicles are more likely to be involved in roadside crashes accounting for about 70% of the crashes. Among all passenger vehicles (passenger cars, vans, pickups, and songtaews (converted passenger pickup), pickups are more likely to be involved in roadside crashes as compared to other passenger vehicle types. Detailed investigation of in-depth roadside crashes is also described. The DOH has started actions the roadside tree problem, a description of the action is described the DOH Roadside Safety Strategic Plan 2009-2013.

Urban Roadside Safety

Roadside safety in rural environments has been the focus of considerable study, but direct application of this knowledge to the constrained urban environment has posed many challenges. Restricted right-of-way with a greater demand for functional use of the space adjacent to urban roads makes the maintenance of a wide clear zone impractical. This paper summarizes a corridor roadside crash analysis used to help identify urban roadside safety issues and illuminate possible solutions for attempting to mitigate objects in the roadside that have the potential to increase injury severity if hit. The paper focuses on arterial and collector-type facilities in urban areas with speed limits between 25 and 50 mph. The authors assessed corridors of urban roadside conditions and compared 6 years of historic crash data with roadside features. The goal of this effort was to identify potential configurations that posed a greater risk by the use of cluster-crash analysis. Locations with similar features without these companion crashes provided insight into prospective alternative treatments for roadside safety in urban environments. The higher-risk roadside locations identified by these approaches were referred to as urban control zones. The most commonly observed roadside crashes included locations in close lateral proximity to the curb face or lane edge, lane merge locations, select auxiliary lane treatments, sidewalk buffer configurations with rigid objects in close proximity to the travelway, driveway and intersection locations, high-cluster-crash locations, and other common roadside crash conditions.

Roadside Crash: A Tragic Lesson from Thailand

Roadside Crash: A Tragic Lesson from Thailand

Comparison of roadside and vehicle crash test injury criteria in frontal crash tests

The flail space model is widely used to assess occupant injury risk potential in full-scale crash tests of roadside safety hardware, e.g. guardrail. A fundamental assumption of this model is that the occupant is unbelted and not airbag restrained. In the early 1980s, these were valid assumptions in the US: cars were not airbag equipped and belt usage rates were around 11%. In today's US vehicle fleet, however, these assumptions are questionable: the belt usage rate is approximately 80% and airbags are required equipment. These changes have significant implications on injury risk computed using the original flail space model. The objective of this study is to contrast flail space model injury risk with the widely accepted dummy-based injury criteria in frontal crashes involving unbelted, belted or airbag restrained occupants. In an analysis of 39 frontal crash tests of speeds ranging from 40 to 97 km/hr, the flail space model was unable to account for variations in occupant risk due to the presence and per...

Comparison of roadside crash injury metrics using event data recorders

The occupant impact velocity (OIV) and acceleration severity index (ASI) are competing measures of crash severity used to assess occupant injury risk in full-scale crash tests involving roadside safety hardware, e.g. guardrail. Delta-V, or the maximum change in vehicle velocity, is the traditional metric of crash severity for real world crashes. This study compares the ability of the OIV, ASI, and delta-V to discriminate between serious and non-serious occupant injury in real world frontal collisions. Vehicle kinematics data from event data recorders (EDRs) were matched with detailed occupant injury information for 180 real world crashes. Cumulative probability of injury risk curves were generated using binary logistic regression for belted and unbelted data subsets. By comparing the available fit statistics and performing a separate ROC curve analysis, the more computationally intensive OIV and ASI were found to offer no significant predictive advantage over the simpler delta-V.

Design of Safe Urban Roadsides: An Empirical Analysis

To date, there has been little examination of the area of roadside safety on nonfreeway urban roads. To understand better the design of safe roadsides in urban environments, this study used negative binomial regression models to examine the safety effects of three roadside design strategies: widening paved shoulders, widening fixed-object offsets, and providing livable-street treatments. The model results indicated that of the three strategies, only the livable-streets variable was consistently and negatively associated with reductions in roadside and midblock crashes. Wider shoulders were found to increase roadside and midblock crashes, while unpaved fixed-object offsets had a mixed safety effect by decreasing roadside crashes but having a slightly positive effect on midblock crashes. To understand better the reasons for these findings, this study then examined roadside crash site locations for tree and utility pole crashes. It found that the majority (between 65% and 83%) did not involve random midblock encroachments, as currently assumed, but instead involved objects located behind both driveways and side streets along higher-speed urban arterials. Collectively, these findings suggest that most urban roadside crashes are not the result of random error but are instead systematically encoded into the design of the roadway. The study concluded by distinguishing between random and systematic driver errors and by discussing strategies for eliminating systematic error while minimizing the consequences of random error.

Design of Safe Urban Roadsides

To date, there has been little examination of the area of roadside safety on nonfreeway urban roads. To understand better the design of safe roadsides in urban environments, this study used negative binomial regression models to examine the safety effects of three roadside design strategies: widening paved shoulders, widening fixed-object offsets, and providing livable-street treatments. The model results indicated that of the three strategies, only the livable-streets variable was consistently and negatively associated with reductions in roadside and midblock crashes. Wider shoulders were found to increase roadside and midblock crashes, while unpaved fixed-object offsets had a mixed safety effect by decreasing roadside crashes but having a slightly positive effect on midblock crashes. To understand better the reasons for these findings, this study then examined roadside crash site locations for tree and utility pole crashes. It found that the majority (between 65% and 83%) did not involve random midblock encroachments, as currently assumed, but instead involved objects located behind both driveways and side streets along higher-speed urban arterials. Collectively, these findings suggest that most urban roadside crashes are not the result of random error but are instead systematically encoded into the design of the roadway. The study concluded by distinguishing between random and systematic driver errors and by discussing strategies for eliminating systematic error while minimizing the consequences of random error.

Marginal Impacts of Design, Traffic, Weather, and Related Interactions on Roadside Crashes

A multivariate model that incorporates the effects of design, traffic, weather, and related interactions with design variables on reported roadside crashes is presented. By providing for a framework that accounts for all measurable effects, the model minimizes the impact of omitted variable effects. Furthermore, the presented framework accounts for partial observability effects that stem from fluctuations in environmental conditions as well as unobserved effects that contribute to heterogeneity in the traffic safety network. A sample of 318 sections 1 mi long was used for the study. These sections represent the state highway network in the state of Washington on the basis of environmental and road classification factors and therefore were used for the collection of detailed precipitation, snowfall, and temperature data in addition to roadway and roadside design and traffic parameters. The resulting model suggests that the marginal impact of weather is both in main effects and interactive form, and that even after controlling for unobserved heterogeneity and partial observability, weather effects play a statistically significant role in roadside crash occurrence. In particular, it was found that in addition to precipitation, average monthly snowfall exceeding 4 in. and interactions between snow depths and horizontal curves were found to have a statistically significant effect on roadside crash frequency probabilities. The marginal effects of these variables were also statistically significant; furthermore, the contribution of weather and related interactions to the likelihood of roadside crash frequencies was approximately 19%, design main effects contributed to 33%, and traffic and design interactions contributed to 6%. Weather interactions with design contributed to approximately 6% of the overall likelihood. Traffic as a main effect contributed 36% to the overall roadside crash likelihood.

Usage of recycled plastic bottles in roadside safety devices

The main objective of this study was to explore the potential of the recycled plastic bottles for the use in a roadside barrier. An analytical method was developed to assess the effectiveness of various bottle energy-absorbing materials as energy-absorbing components of a roadside crash barrier. Based upon results of a literature survey, an analytical model was developed and coded into a computer program. The model was used to perform statistically design material experiments to assess the potential of a crash barrier design and determine the optimal configuration. The main conclusion is that the analytical barrier model provides a simple and direct means to assess the non-linear crush behaviour of a series of impacting bodies. Also, recycled plastic bottles appear to offer a roadside crash barrier whose impact severity index is on the road order of 10 percent of the severe-injury threshold. Further refinement of the car-barrier model would be required to permit a more through investigation of crash barrier design analysis.

Tools to Identify Safety Issues for a Corridor Safety-Improvement Program

The Arizona Department of Transportation (ADOT) recognizes that a new paradigm in highway safety evaluation was brought about by the advent of advanced technologies such as photo log, geographic information systems (GIS), and global-positioning satellite systems. Whereas these technologies are known to serve distinct singular purposes in a highway agency, ADOT has endeavored to explore the possibilities of integrating these technologies for the purpose of providing an all-encompassing perspective of crash history and roadside characteristics in a multimedia display of GIS maps and related photo imagery. The research provides the account of an analytic tool-development process aimed at improving the recognition of highway safety hazards. These hazards might otherwise be apparent if not for the relative complexity of existing relational databases and spatial GIS infrastructure at ADOT. Previous methods of mining data from the ADOT crash databases were limited in functionality as well as in reliability. By promoting the “visualization” of highway safety conditions, the advanced technologies open a wealth of new opportunities in identifying problematic roadside conditions and crash histories. This is expected to lead to an improved economy of implementing safety improvements that are designed properly to mitigate the “real” conditions that can be identified. The research is a companion to the larger, FHWA-sponsored research into establishing a corridor safety-improvement program for Arizona (FHWA Report FHWA-AZ 98-458).

Computer Simulations of Roadside Crash Cushion Impacts

This paper presents the results of finite element computer simulations of vehicular impacts with a roadside crash cushion. DYNA3D is used to model the energy-dissipating response of the Narrow Connecticut Impact Attenuation System under high-speed impacts with heavy and light vehicles. The finite element predictions are compared with the experimental results of full-scale crash tests involving automobiles impacting the device at 97 km/h. It is demonstrated that computer simulations can effectively model the dynamic response of a crash event and provide valuable measures of occupant risk. Computer simulations allow the investigation of crash scenarios involving nontracking, braking, and turning vehicles. Such full-scale crash events are very difficult to conduct in the field. It is recommended that these simulation tools be used more extensively in the design of roadside safety features so that the number of expensive full-scale crash tests required to develop future hardware can be minimized.

Effectiveness of roadside crash countermeasures

A survey of design and traffic engineers in each of the 50 states of America was carried out to choose one of a group of three alternatives they considered most beneficial in reducing accidents. The questionnaire contained 18 such groups. An example is quoted of the choice of: (a) realignment at one location; (b) roadside/slope modification at two locations; or (c) guardrail at four locations. Analysis of the responses showed good agreement in that total reconstruction should be considered if it is less than 2.5 times the cost of the roadside/slope modifications, and less than 3.5 times the cost of guardrail installation. The survey indicated that roadside/slope modification would be preferred if realignment were greater or equal to 2.5 times the cost of roadside/slope modifications and less than or equal to 2.75 times the cost of a guardrail. Results given are subjective judgements of professionals regarding the safety of hypothetical cases. Other measures could be used in practice and it is not certain that the recommended measures are either effective or representative of current practice. (TRRL)

Recent Developments in Roadside Crash Cushions

Collision with a fixed object is the leading source of fatalities on the Interstate Highway System and other freeways. Among the efforts to reduce this toll has been the development and installation of impact attenuators in a number of states at elevated exit ramps. Design criteria presently used by the Federal Highway Administration are intended to result in barriers which will result in survivable impacts for the vast majority of high speed collisions. Field data relating to these design criteria are presented. Accident experience to date with these barriers is presented and has confirmed the expectation of their potential to significantly reduce accident severity. Further research is underway to extend the list of roadside conditions for which such barriers would be a cost effective lifesaving tool.