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Collisions of over-height vehicles with low clearance bridges is commonly encountered worldwide. They have caused damage to bridge structures, interruption to traffic, injuries or even fatalities to road users. To mitigate such risks, passive systems that involve warning gantries, flashing lights and illuminated signage are commonly installed. Semi-active systems using laser- or infrared-based detection systems in conjunction with visual warnings have been implemented. Nevertheless, some drivers ignore these visual warnings and collisions continue to occur. This paper presents a novel concept for a collision prevention system, which makes use of a series of sensor-activated, motorized rumble strips. These rumble strips span across a certain distance ahead of a low clearance bridge. When an over-height vehicle is detected, a mechanism is triggered which elevates the rumble strips. The noise and vibrations produce a vigorous alert to the offending driver. They also increase effective friction of the road surface, thus assisting to slow down the vehicle and shorten the stopping distance. The strips will be lowered after a certain time has elapsed, thus minimizing their effects on other vehicles. This article presents a conceptual framework and quantifies the vibration and noise caused by rumble strips in road tests. Road tests indicated that the vibration level typically exceeded 1 g and noise level reached approximately 90 dB in the cabin of a 3.5-ton truck. Fabrication of a proof-of-concept mechanized rumble strip model was presented and verified in an outdoor environment. The circuitry and mechanical design, and requirements in actual implementation, are discussed. The proposed event-triggered rumble strip system could significantly mitigate over-height vehicle collisions that cause major disruptions and injuries worldwide. Further works, including a comprehensive road test involving various types of vehicles, are envisaged. [ABSTRACT FROM AUTHOR]

Collisions of over-height vehicles with low clearance bridges is commonly encountered worldwide. They have caused damage to bridge structures, interruption to traffic, injuries or even fatalities to road users. To mitigate such risks, passive systems that involve warning gantries, flashing lights and illuminated signage are commonly installed. Semi-active systems using laser- or infrared-based detection systems in conjunction with visual warnings have been implemented. Nevertheless, some drivers ignore these visual warnings and collisions continue to occur. This paper presents a novel concept for a collision prevention system, which makes use of a series of sensor-activated, motorized rumble strips. These rumble strips span across a certain distance ahead of a low clearance bridge. When an over-height vehicle is detected, a mechanism is triggered which elevates the rumble strips. The noise and vibrations produce a vigorous alert to the offending driver. They also increase effective friction of the road surface, thus assisting to slow down the vehicle and shorten the stopping distance. The strips will be lowered after a certain time has elapsed, thus minimizing their effects on other vehicles. This article presents a conceptual framework and quantifies the vibration and noise caused by rumble strips in road tests. Road tests indicated that the vibration level typically exceeded 1 g and noise level reached approximately 90 dB in the cabin of a 3.5-ton truck. Fabrication of a proof-of-concept mechanized rumble strip model was presented and verified in an outdoor environment. The circuitry and mechanical design, and requirements in actual implementation, are discussed. The proposed event-triggered rumble strip system could significantly mitigate over-height vehicle collisions that cause major disruptions and injuries worldwide. Further works, including a comprehensive road test involving various types of vehicles, are envisaged.

Despite numerous research studies inspecting the safety benefits of centreline and shoulder rumble strips (RS) on pavements, there has been limited exploration into the impact on pavement durability due to the installation of RS. The RS milling process creates micro-cracks in the pavement structure that could propagate to macro cracks over time with freeze and thaw, moisture damage, and traffic loading, thereby decreasing the lifespan of the pavements. The primary objective of this study was to develop testing procedures for RS samples as well as analysis methods to determine the impact of potential controlling factors such as permeability and resulting moisture damage; freeze–thaw; the presence of microcracks; surface layer sealants (chip seal); RS size, depth, type, and RS location in relation to the longitudinal construction joint. The flexural beam fatigue test suggests that sinusoidal rumble strips had 38% increased fatigue cracking resistance. Moreover, the sinusoidal rumble strip resulted in 41% improved cracking and structural performance in the Hamburg Wheel Tracking Test (HWTT) tests. Also, the rutting performance of sinusoidal rumble strips was similar to the control section without rumble strips. In addition, 0% moisture infiltration was observed in sinusoidal rumble strip specimens. [ABSTRACT FROM AUTHOR]

Abstract Highway work zones are associated with significant adverse impacts on safety. Mitigating these impacts can be achieved by implementing several countermeasures. This paper uses controlled experiments in a driving simulator to investigate the effects of physical and digital temporary traffic control countermeasures on work zone safety. These include variable message signs, dynamic speed displays, rumble strips, and lane widths. 116 participants were recruited for the experiment. A linear mixed-effects model was developed to capture the effects of these countermeasures on average travel speed and standard deviation of speeds in the advanced warning area and within the work zone itself. The results reveal that rumble strips installed within the work zone cause the strongest reduction in speeds. Narrower lanes cause smaller speed reductions. In general, the effects of temporary traffic control countermeasures on speeds were local and were not retained beyond their proximity.

Highway work zones are associated with significant adverse impacts on safety. Mitigating these impacts can be achieved by implementing several countermeasures. This paper uses controlled experiments in a driving simulator to investigate the effects of physical and digital temporary traffic control countermeasures on work zone safety. These include variable message signs, dynamic speed displays, rumble strips, and lane widths. 116 participants were recruited for the experiment. A linear mixed-effects model was developed to capture the effects of these countermeasures on average travel speed and standard deviation of speeds in the advanced warning area and within the work zone itself. The results reveal that rumble strips installed within the work zone cause the strongest reduction in speeds. Narrower lanes cause smaller speed reductions. In general, the effects of temporary traffic control countermeasures on speeds were local and were not retained beyond their proximity. [ABSTRACT FROM AUTHOR]

A safety treatment of shoulder rumble strips, shoulder widening [from 0 to 0.6 m (2 ft)] and pavement resurfacing (RSR) was deployed to over 644 centerline km (400 mi) of rural two-lane highways in Missouri. The effectiveness of the RSR treatment was evaluated with the empirical Bayesian before/after study method based on the roadway characteristics, traffic and crash data collected. Crash modification factors (CMF) for 20 categories of crash severity and/or collision type were calculated. Generally, the RSR treatment is effective for improving the safety performance of rural two-lane roads, especially for fatal and injury crashes. The RSR treatment is specifically effective for run-off road and head-on crashes. A cumulative residual (CURE) analysis reveals that fixed-value CMFs for all annual average daily traffics (AADT) range are likely to result in biased estimation on the RSR’s safety effectiveness. The crash modification function (CMFunction) was introduced in this study and a sample size of 32 was selected to develop the CMFunction based on the sensitivity analysis results. CMFunctions were developed for two collision types of different crash severities. The CURE plot indicates that crashes predicted with CMFunctions are more accurate than those with CMFs and therefore CMFunctions are more reliable than fixed-value CMFs for evaluating the effectiveness of safety treatments. [ABSTRACT FROM AUTHOR]

In response to increasing traffic crashes along highways in Africa, various interventions have been adopted with varied outcomes. Though the specific impacts of various interventions have not been measured, rumble strips appear to be the dominant choice in many countries around Sub-Saharan Africa. Using the Accra-Cape Coast trunk road, a section of the trans-West African highway in Ghana, this study explores the speed reduction effects of rumble strips. In spite of the many traffic-calming interventions introduced on sections of the road, the road is reported to have recorded hundreds of traffic crashes in the last decade. Adopting a quasi-experimental design, thirty-six (36) study sections were delineated, and installed rumble strips were inventoried. Spot speeds were measured on sections “with” and “without” the installed rumble strips, all within communities and known blackspots. Existing data on traffic and road crashes were obtained from secondary sources and reviewed to set the context for effective comparison. The study revealed violations in speed limits at 70% of study locations with only rumble strips installed by 4 km/h. Road traffic crashes tend to cluster with speed ranges of between 54 km/h and 70 km/h. Thus, with the right combinations of interventions, speed and traffic crashes can be substantially reduced along the highway. Policy implications for road safety regulation have also been discussed.

Transverse rumble strips (TRS) are commonly used as traffic calming measure in the vicinity of premises. So far research have been extensively concentrated on the effect of vehicle type and speed on the noise produced by TRS, and very little research focused on the effect of vehicle weight. Do these vehicles produce extremely higher sound level parallel to their heavier weight? This is important as in reality, traffic flow consist of light, medium and heavy vehicles, which are also important sources of noise. This study investigated the effect of vehicle weight, such as gross vehicle weight (GVW) when transited on TRS, particularly with emphasis on impulsivity content. The objectives of this research were to: (1) determine the effect of GVW on noise generation when a vehicle transits on TRS and (2) assess the effect of GVW on the impulsivity of noise. Data from vehicles with weight between 800 kg - 8000 kg were collected based on previous research where these vehicles were tested on speed values of 30km/h and 50km/h. It was found that when the vehicles transited on TRS, the generated noise was strongly related with the vehicle weights (R2=0.71) higher than those normal road surface (R2=0.49). However, the changes of noise were not well represented by direct relation. It was found that TRS can increase and decrease the sound pressure level, depending on GVW, but on average, TRS can increase the sound pressure level by 1 dBA. Despite that, TRS was found to have an impulsive characteristic within the tested speed range. This finding can facilitate the authority to evaluate the environmental noise produced by TRS.

A systemic approach to safety management has potential to be more cost effective than a traditional hot-spot approach in reducing crash frequency as it aims to identify sites with promise (SWiPs) by targeting certain crash types and select countermeasures accordingly, and therefore, effectively connects target crashes to their corresponding countermeasures. Although it seems to be promising, there are many challenges to evaluate the effects of countermeasures under the systemic approach, i.e. evaluate the effects of countermeasures by crash types. These challenges mainly include (1) low sample mean, (2) correlation among crash types, and (3) correlation among the effects of countermeasures on different crash types. A random parameter multivariate Poison lognormal (random parameter MVPLN) model is proposed. It was shown that the random parameter MVPLN model not only mitigates the three challenges, but also provides useful information than traditional crash frequency models. Shoulder rumble strips were found to be effective in reducing fix-object crashes, the primary crash type targeted by this countermeasure. The effectiveness of shoulder rumble strips on fixed-object crashes was found to be positively correlated with opposite-direction sideswipe and head-on crashes, meaning that the effects of shoulder rumble strips on fixed-object crashes would spillover to opposite-direction sideswipe and head-on crashes. [ABSTRACT FROM AUTHOR]

This paper summarizes the results of Phase II of a research project developing a novel design of directional rumble strips (DRSs) to deter wrong-way driving (WWD) onto freeway off-ramps. In Phase I of this project, five concept designs of the DRS (named from A to E) were developed to generate elevated sound and vibration to warn against WWD and to generate normal sound and vibration to slow down the right-way (RW) traffic. After initial field tests in Phase I, three final conceptual DRS designs were selected for further field verification, specifically, Patterns C, D3, and E1. Pattern C was designed based on traditional transverse rumble strips (TRSs), but the spacing between the strips was changed to generate different rhythms of sound and vibration. Pattern D3, which was modified based on the advance warning markings for speed humps, increases in thickness and length in each strip. Pattern E1 has a right-angled triangle cross section that can produce the most recognizable sound and vibration from the WWD direction among the three patterns. The objective of this paper was to document the field verification results of the final three patterns and to develop implementation recommendations for applying them on off-ramps. Overall, the field verification results indicated that the tested DRS can generate recognizable interior sound and a moderate amount of vibration to alert wrong-way drivers. Recommendations for implementation were also developed for transportation agencies to identify proper locations for installing them to achieve the best performance based on type and length of off-ramp. [ABSTRACT FROM AUTHOR]

Large-scale deformations of a tubular object, or generalized cylinder, are often defined by a target shape for its center curve, typically using a parametric target curve. This task is non-trivial for free-form deformations or direct manipulation methods because it is hard to manually control the centerline by adjusting control points. Most skeleton-based methods are no better, again due to the small number of manually adjusted control points. In this paper, we propose a method to deform a generalized cylinder based on its skeleton composed of a centerline and orthogonal cross sections. Although we are not the first to use such a skeleton, we propose a novel skeletonization method that tries to minimize the number of intersections between neighboring cross sections by means of a relative curvature condition to detect intersections. The mesh deformation is first defined geometrically by deforming the centerline and mapping the cross sections. Rotation minimizing frames are used during mapping to control twisting. Secondly, given displacements on the cross sections, the deformation is decomposed into finely subdivided regions. We limit distortion at these vertices by minimizing an elastic thin shell bending energy, in linear time. Our method can handle complicated generalized cylinders such as the human colon. [ABSTRACT FROM AUTHOR]

Rumble strips aim to alert the driver of dangerous situations via acoustic and tactile stimulation. They can, however, also lead to increased noise in the surroundings. Strip parameters and the vehicle type determines the size of these acoustic and vibratory effects. In our work, 16 rumble strip types (including strips with irregular spacing) were evaluated with respect to their effects on acoustics, vibration, and perception. Interior and exterior emissions caused by controlled pass-overs of a car and a truck were recorded. Annoyance, urgency, and reaction time of 16 listeners were tested in a laboratory experiment and models mapping acoustics to perception were developed. Steering wheel and seat vibrations were acquired. Our results show a high correlation of interior and exterior noise. The loudness level was the best predictor of perceived annoyance and urgency. Irregular spacing reduced the tonality at the cost of a difficult production process. While a large variety of strip types produced a sufficient acoustic effect in the passenger car, the acoustic response was lower in the truck. Combined with the low vibration levels found in the truck, an identification of an optimal strip type for both vehicle types turns out to be difficult.

In India, road accident is one of the major factors responsible for most deaths. Every Year almost 0.15 million people die on Indian roads every year and the major factor responsible is human errors that account for almost 80% of the accidents and these human errors are the results of engineering defects in 70%-80% cases. These human errors could be asleep, fatigue, inattentiveness, Distraction etc that led to road or lane departure. Shoulder rumble strips (SRS) and center line rumble strips (CLRS) are the techniques that could be proved a milestone in making our roads more favorable to drive and more forgiving. We observed that there is no such measure taken on Indian roads which can alert road user before losing their lane. SRS and CLRS somehow alert road users by shaking vehicle and making a loud noise so as to avoid off - road crashes. These two techniques come under the category of lane departure warning system. Location of these techniques can be identified by black spot data for the country. Indian road users could be benefited from this technique of making roads more alerting and forgiving so as to reduce the accidents by compensating human errors. [ABSTRACT FROM AUTHOR]

Transverse rumble strips (TRS) are a common choice to reduce vehicle speed and increase driver alertness on roadways. However, there is a potential trade-off using them on rural roadway due to the noise problem created when vehicles go over the strips. The present study investigated the noise level, spectral analysis, and the possible noise generation mechanism when the TRS is hit by a vehicle. Tenraised- rumbler (RR) and three-layer-overlapped (TLO) TRS were selected in this study as they have received complaints from the public. Results showed that RR generated a relatively higher noise and impulse at a low speed, and increased sound level in each octave band. Based on these results, RR may irritate human ears even when the vehicle travels at a low speed. It was found that RR increased all noise generation mechanisms of tyre-pavement interaction whilst TLO increased structural resonance, sidewall and surface texture vibration. [ABSTRACT FROM AUTHOR]

This study focuses in the impact of vehicle speed, vehicle type, and transverse rumble strip (TRS) design on the sound pressure level perceived by drivers when they traverse a TRS. TRSs are commonly installed on approaches to toll plazas and at intersections, etc. The ability of a TRS to capture a driver's attention is directly related to the magnitude of the sound and vibration. However, the traffic noise generated by TRS creates a problem for adjacent residences and businesses near the roadway. Thus, the aim of this study is to quantify the level of traffic noise and verify the effects of TRS shapes. The research team measured the exterior noise, inner noise, and vibration generated by three types of vehicles (sedan, minivan, and truck) traveling over four types of transverse rumble strip applications (Types A, B, C, and D) with speed range between 40 and 100 km=h. In general, the increase in the exterior noise generated was greater at 100 km=h than at 40 km=h and lower for a sedan than for a truck. Type A generated the highest exterior noise and Type C generated the highest inner noise. The sound level clearly changed according to TRS dimension such as shape, width, and length, etc. Type C showed the best performance with a lower sound pressure level, effective ability to alert the driver, and reduced complaints from adjacent residents after implementation on a highway road in Korea. [ABSTRACT FROM AUTHOR]

There are several issues attributed with abdominal aortic aneurysm endovascular repair. The positioning of bifurcated stent-grafts (SG) may affect SG hemodynamics. The hemodynamics and geometrical parameters of crossing or non-crossing graft limbs have not being totally accessed. Eight patient-specific SG devices and four pre-operative cases were computationally simulated, assessing the hemodynamic and geometrical effects for crossed ( n = 4) and non-crossed ( n = 4) configurations. SGs eliminated the occurrence of significant recirculations within the sac prior treatment. Dean's number predicted secondary flow locations with the greatest recirculations occurring at the outlets especially during the deceleration phase. Peak drag force varied from 3.9 to 8.7 N, with greatest contribution occurring along the axial and anterior/posterior directions. Average resultant drag force was 20% smaller for the crossed configurations. Maximum drag force orientation varied from 1.4° to 51°. Drag force angle varied from 1° to 5° during one cardiac cycle. 44% to 62% of the resultant force acted along the proximal centerline where SG migration is most likely to occur. The clinician's decision for SG positioning may be a critical parameter, and should be considered prior to surgery. All crossed SG devices had an increased spiral flow effect along the distal legs with reductions in drag forces. [ABSTRACT FROM AUTHOR]

Rumble strip implementation has shown a constant increase with its safety benefits. Rumble strips are milled into the roadway shoulder to produce noise and vibrations when driven on. With the milling process, the pavement performance is expected to be negatively impacted by the decreased depth, though not mathematically quantified. Using methods defined by the Long-Term Pavement Performance Program, the severity of the shoulder site's distresses, with and without shoulder rumble strips, will be quantified. The quantification would permit the design to compensate for the impact. This design compensation allows the implementation of hard shoulder running, the use of shoulder as a travel lane during congestion, and retains the shoulder rumble strip safety instead of removing, as suggested by some proposed projects. While hard shoulder running would not impact specific time periods, the safety benefit of rumble strips could be needed at any time. This study aims to quantify the rumble strip impact to enable the full shoulder strength for hard shoulder running while retaining the safety benefits of rumble strips. [ABSTRACT FROM AUTHOR]

The combined application of centerline and shoulder rumble strips is intended to reduce the frequency of crashes by alerting drivers that they are about to leave the traveled lane. To date, this combination treatment has not been rigorously evaluated with a multistate database. To fill this void, this study evaluated treated two-lane rural road locations in three states. To account for potential site selection bias, an empirical Bayes (EB) before-after analysis was conducted. The combined results for all states indicate statistically significant crash reductions for all crash types analyzed. The crash type with the smallest crash modification factor (CMF) (i.e., the greatest crash reduction) is head-on with a CMF of 0.632 (i.e., a crash reduction of 36.8%). For run-off-road, head-on, and sideswipe-opposite direction crashes combined (i.e., lane departure crashes), the estimated CMF is 0.733. Benefit:cost (B:C) ratios were estimated to range from 28.2 to 67.7, depending on the treatment cost and service life assumption. [ABSTRACT FROM AUTHOR]

The article explores The willingness of our members to consistently support and offer their time to GLA speaks volumes about the greatness within. author want to thank all who accepted or transitioned into leadership roles for committees, divisions, interest groups, and other singular roles. Your "call to action" is commended and appreciated. I am especially grateful to Angela Cortellino and Kara Rumble who stayed the course for another year of advocacy and conference leadership.

Many surveyors who work in/near live traffic encounter unique safety challenges as they are frequently exposed to fast moving vehicles. Unlike traditional work zones, safety countermeasures at surveying sites are usually limited to advanced-warning signs, traffic cones and reflective safety vests. As a result, motorists may not be well alerted for the presence of surveyors. Because of the unique safety challenges encountered by surveyors and the motorists, this study aims to quantify the effectiveness of using temporary rumble strips, as a potential safety countermeasure in enhancing safety at surveying work sites. A type of portable plastic rumble strip (PPRS) was tested at eight land surveying sites in New Jersey. The effectiveness of PPRS was evaluated based on selected surrogate measures of effectiveness (SMOE) that were extracted from the video data recorded during the 2-h field test at each site. Statistically significant reductions in driving speed and speeding proportion, and increases in braking rate were found when the rumble strips were deployed during the field tests. These observed changes suggest that the deployment of PPRS can be a useful countermeasure to increase motorists' awareness at land surveying sites. The findings can serve as a reference for practitioners when deploying temporary and portable traffic control device in these unique short-term work zones. [ABSTRACT FROM AUTHOR]

Limit equilibrium is a common method used to analyze the stability of a slope, and minimization of the factor of safety or identification of critical slip surfaces is a classical geotechnical problem in the context of limit equilibrium methods for slope stability analyses. A mutative scale chaos optimization algorithm is employed in this study to locate the noncircular critical slip surface with Spencer's method being employed to compute the factor of safety. Four examples from the literature--one homogeneous slope and three layered slopes--are employed to identify the efficiency and accuracy of this approach. Results indicate that the algorithm is flexible and that although it does not generally provide the minimum FS, it provides results that are close to the minimum, an improvement over other solutions proposed in the literature and with small relative errors with respect to other minimum factor of safety (FS) values reported in the literature. [ABSTRACT FROM AUTHOR]

Long distance driving exposes drivers to microsleep or drowsiness that can possibly cause run-off-road accidents. It is therefore, crucial to install safety devices for alerting drivers in order to prevent accidents. This study aimed to test the efficiency of shoulder rumble strips (SRS), which is renowned as a safety device, designed for preventing accidents. The study determines if SRS are statistically significant in creating high alarm levels to warn unmindful or drowsy drivers. It also examines the efficiency differences among the three types of SRS: profiled; milled-in; and transverse. The study findings showed that the three types of SRS can increase noise levels, ranging from 9.97 dBA to 17.47 dBA, which are enough to alert the drivers. Results revealed that efficiencies of both profiled and transverse SRS were significantly similar, whereas milled-in SRS showed efficiency differences at all speeds and reported the lowest increase in noise level. [ABSTRACT FROM AUTHOR]

Highlights: [•] Although it is important to precisely evaluate the effectiveness of candidate countermeasures in reducing the number of severe crashes at a site, the current state-of-the-practice often leads to biased estimates. [•] We propose an approach which decomposes the severe crash frequency into a function of the change in the total number of crashes and the probability of a crash becoming a severe crash after a countermeasure is implemented. [•] This approach is tested by evaluating the effectiveness of shoulder rumble strips on reducing severe crash frequency. [ABSTRACT FROM AUTHOR]

Objective:Since land surveyors working alongside live traffic encounter unique safety challenges there is a great need for innovative and effective traffic control devices (TCDs) that alert motorists approaching short-term land surveying work sites. Unlike the volume of research that has been completed on traditional work zones, however, there is a limited amount of information that has been collected on how motorists respond to TCDs at land surveying work sites. This article aims to fill the void by investigating motorists’ behaviors in response to the use of 2 supplementary TCDs at land surveying work sites: portable plastic rumble strips (PPRS) and warning lights. Method:Extensive field tests were conducted at various land surveying work sites on 2-lane 2-way urban roadways in New Jersey. Scenarios with and without the use of the supplemental TCDs were designed. Motorists’ behavior changes were then statistically examined by using surrogate safety measures including mean speed, speed variance, speed limit compliance, and braking action. Results:Statistical analyses showed that the traffic speed variations did not significantly increase when the selected supplemental TCD was used; rather, motorists significantly reduced their driving speed. When warning lights and PPRS were separately deployed at the land surveying work sites the average reduction in mean speed was 6.7 and 15.2 percent, respectively. The mean speed was reduced by 19.7 percent when both of these supplementary TCDs were used. Logistic regression models developed to examine the speeding and braking behavior also showed that motorists were more likely to comply with the speed limit and increase their braking rate when the selected TCDs were used. Conclusion:The use of supplemental TCDs can greatly contribute to the changes in motorists’ behaviors at surveying work sites. The changes in motorists’ driving behaviors imply that the motorists reacted favorably to the deployed TCDs at the land-surveying work sites. [ABSTRACT FROM AUTHOR]

Controlled field studies were performed at 12 locations to evaluate the impacts of milled centerline rumble strips on exterior roadside noise adjacent to rural two-lane highways as a function of rumble strip depth and pavement type. Twenty controlled pass-bys were performed at each location using a minivan traveling at (55 mph). An equal number of passes were made both while traveling on and off of the centerline rumble strips, with the latter condition providing baseline noise data. The maximum noise was recorded during each pass using a digital sound meter that was placed 15.24 m (50 ft) laterally from the centerline of the roadway at a height of 1.52 m (5 ft) above the pavement surface. Multiple linear regression models were estimated to ascertain the effects of depth and pavement type while controlling for baseline noise. The milled depth of the rumble strips was the strongest predictor of roadside noise, and this effect was stronger for hot mix asphalt pavements compared to chipsealed pavements. For every 1.5875 mm () increase in centerline rumble strip depth, roadside noise increased by 2.3 decibels on hot mix asphalt pavements, compared to 1.4 decibels on chipsealed pavements. [ABSTRACT FROM AUTHOR]

Abstract: Increases in noise due to the installation of transverse rumble strips were investigated, by first measuring noise due single vehicles crossing a pilot test field with and without a rumble strip. After that, a procedure was proposed and carried out to estimate increases in noise due to the traffic of vehicles, based on the measurements previously mentioned. This procedure was checked against expressions from the literature that estimate traffic noise as well as measurements in three arterial urban roads without rumble strips installed. Its accuracy was compatible with the ones obtained by applying the literature expressions, the errors lying below 3dB(A). Then, by taking the aforementioned roads as case studies, estimations were carried out for the increases that would occur in noise levels if rumble strips were installed on them, leading to values between 6 and 7dB(A). Although such values are dependent on the configuration of the rumble strip employed, the proposed procedure presents generality and could be applied to estimate increases in traffic noise due to installation of rumble strips, by departing from measurements of noise due to single vehicles obtained for a given rumble strip configuration. [Copyright &y& Elsevier]

The occurrence of roadway departure crashes is a serious problem in the United States. These types of crashes correspond to approximately 40% of all crashes in the United States, and their estimated annual cost is $100 billion. The objective of this study was to quantify the safety effectiveness of center line rumble strips (CLRS) in Kansas. CLRS are raised or grooved patterns installed on the center of two-lane, undivided, rural highways to prevent mainly cross-over crashes, more specifically head-on and sideswipe in opposite direction types of crashes. In this study, 29 sections of highways with two patterns of CLRS (rectangular and football) were analyzed, totaling more than 590 km. The naïve and the empirical Bayes before-and-after methods were applied and compared. Results showed that following the installation of CLRS, total crashes judged to be correctable by CLRS were reduced by approximately 29%. Correctable crashes involving fatalities and injuries were reduced by approximately 34%. Cross-over crashes were reduced by approximately 67%. Run-off-the-road crashes were reduced by 19%. All comparisons except for run-off-the-road crashes were statistically significant. The two methods applied presented statistically similar results. There was no statistical differences between results from sections with rectangular or football shaped CLRS. [ABSTRACT FROM AUTHOR]

This study evaluated the effects of portable plastic rumble strips (PPRSs) on speed reduction and drivers' behaviors in advance of flagger-controlled work zones. Travel speed data were collected at three two-lane highways with temporary (less than a day) maintenance activities, at which standard flagger traffic control was set up with or without the implementation of PPRSs. Drivers' reactions to the PPRSs, such as changing lanes and braking in the vicinity of the PPRSs, were also investigated when the PPRSs were in place. The results showed that drivers became more cautious because of the PPRSs. The PPRSs reduced car mean speeds by 9.7 to (6.0 to ). They also decreased the 85th percentile of car speeds at two field test sites. It was observed that 30 to 80% of all drivers activated their brakes when they approached the PPRSs close to the flagger. In addition, about 5% of car and truck drivers swerved around the PPRSs. This indicates that additional signing or other supplemental traffic devices would be needed when the PPRSs are implemented. [ABSTRACT FROM AUTHOR]

Abstract: The primary objective of this study is to evaluate the impacts of transverse rumble strips in reducing crashes and vehicle speeds at pedestrian crosswalks on rural roads in China. Using crash data reported at 366 sites, the research team conducted an observational before-after study using a comparison group and the Empirical Bayesian (EB) method to evaluate the effectiveness of transverse rumble strips in reducing crashes at pedestrian crosswalks. It was found that transverse rumble strips may reduce expected crash frequency at pedestrian crosswalks by 25%. The research team collected more than 15,000 speed observations at 12 sites. The speed data analysis results show that transverse rumble strips significantly reduce vehicle speeds in vicinity of pedestrian crosswalks on rural roads with posted speed limits of 60km/h and 80km/h. On average, the mean speed at pedestrian crosswalks declined 9.2km/h on roads with a speed limit of 60km/h; and 11.9km/h on roads with a speed limit of 80km/h. The 85th percentile speed declined 9.1km/h on roads with a speed limit of 60km/h; and 12.0km/h on roads with a speed limit of 80km/h. However, the speed reduction impacts were not found to be statistically significant for the pedestrian crosswalk on the road with a speed limit of 40km/h. The study also looked extensively at the influence area of transverse rumble strips on rural roads. Speed profiles developed in this study show that the influence area of transverse rumble strips is generally less than 0.3km. [Copyright &y& Elsevier]

A field study was conducted on a Missouri low-volume road to examine if temporary rumble strips could improve safety in elevated-risk work zones. This study complements previous studies by addressing several new issues: vehicles that cross over a lane to bypass strips, physical displacement of strips, and deployment of strips at an angle. An objective was to measure performance in a challenging and nonidealized site, thus the site contained geometric challenges such as curves, a bridge approach, and a pavement transition. The study found an increase of more than 10% in the number of vehicles that braked due to rumble strips, an average speed decrease of up to 6 kilometers per hour (3.7 miles per hour), and an increase in speed compliance of 2.9% for the braking vehicles. But the number of lane crossovers increased by 8.79%. The study also compared rumble strips deployed perpendicularly and at an angle and found no significant differences in braking and speed reductions but found an increase in lane crossovers. In terms of vertical movement, perpendicular strips did not move whereas angled strips moved up to 3.73 cm per 100 wheel impacts. Taking into account all study measures, the rumble strips provided a net improvement in safety. [ABSTRACT FROM AUTHOR]

The article discusses a study conducted to know the effects of sleep loss on driving behaviour and subjective sleepiness ratings when driving on a road with a milled rumble strip in the centre of the lane. While comparing the alert condition with the sleep deprived condition, the study results found both the Standard Deviation of Lateral Position (SDLP) and the Karolinska Sleepiness Scale (KSS) increased for drivers with sleep deprivation.

Centerline rumble strips (CLRS) are patterns installed on the center of undivided, two-lane highways. Their main function is to alert drivers by producing noise and vibration. This treatment has been demonstrated to be effective in reducing crossover crashes. However, there are some disadvantages in their utilization, such as the exterior noise created by the strips. The objectives of this study were to quantify the levels of exterior noise; to verify the effects of speed, vehicle, CLRS shape, and distance on exterior noise; and to investigate the amount of noise created by CLRS that affects roadside residences and businesses. Two types of vehicles [2006 Ford Taurus (sedan) and 2008 Chevrolet Express (15 passenger van)] were driven over two different patterns of milled-in CLRS and over smooth asphalt pavement at two different speeds. Researchers collected the noise levels at three distances from the road at 10 different locations. Results indicated that vehicle type, speed, CLRS presence, and distance affect exterior noise levels. CLRS noise levels were statistically greater than smooth pavement noise levels, and the difference would be perceived by human ears at distances up to 45 meters. [ABSTRACT FROM AUTHOR]

Objective: Sealing of road shoulders and installation of audible edge lines (also known as rumble strips or audio tactile profiled edges) are common engineering road treatments, often implemented to prevent run-off-road crashes. This quasi-experimental study evaluated the effectiveness of installing sealed shoulders and/or audible edge lines on the Albany Highway in Western Australia during 2000-2004 relative to matched control sites. Methods: Reduction in crash frequency post-2004 and the economic benefits of applying these treatments to 13 sites were assessed. Results: The treatments were highly effective overall, significantly reducing all-severity crash rate by 58 percent and casualty crashes by 80 percent. The reduction in crash cost was estimated to be $51.9 million Australian dollars over the lifetime of the treated sites, with $51.4 million attributable to the decrease in casualty crashes. After accounting for treatment costs, the net cost savings to the community were estimated at $50.6 million. The benefit-cost ratio across all treatment sites was 40.3. Conclusions: The findings justified the implementation of these treatments on rural roads in terms of benefits for reduction in both crash rate and crash cost. [ABSTRACT FROM AUTHOR]

Understanding of the fate of pollutants, disposed of in streams, is a matter of concern in recent years for the effective control of pollution. Transverse mixing of the pollutants in open channels is arguably more important than the longitudinal mixing and near-field mixing. Several attempts have been made to establish the relationship between the transverse mixing coefficient and bulk channel and flow parameters such as width, depth, shear velocity, friction factor, curvature and sinuosity. This paper presents adaptive neuro fuzzy inference system (ANFIS) approach to predict the transverse mixing coefficient in open channel flows. Available laboratory and field data for the transverse mixing coefficients covering wide range of channel and flow conditions are used for the development and testing of the proposed method. The proposed ANFIS approach produces satisfactory results (R2=0.945) compared to the artificial neural network (ANN) model and existing predictors for mixing coefficient. [ABSTRACT FROM AUTHOR]

Rumble strips have been installed on highway pavements to reduce vehicle collisions involving vehicles either running off road and/or crossing over centerlines. The rumbling effect may be understood in part as tactile inputs to waken inattentive and/or fatigue drivers. The tactile jerking effect, characterized by jerk intensity experienced by drivers, is analyzed for milled-in rumble strips with different geometric parameters using a quarter vehicle model. Our analysis shows that the optimal rumble strip width lies somewhere around 180 mm, and the ranges of the design parameters can be selected to control the jerking magnitude to alarm a driver in an errand vehicle. These parameter ranges are in part confirmed by experimental data reported in literature. This new rumble strip design strategy, practically more adaptable and effective, can be widely applied on highways of various functional classes. [ABSTRACT FROM AUTHOR]

This research was conducted to determine how best to incorporate portable rumble strips into traffic control plans for short-term work zones. One objective of the research was to provide guidance on how existing traffic control plans could be amended to include provisions for the evaluated devices. This research focused on rumble strips that were considered beneficial for any type of work zone where the duration is one day or less. The tests on the portable rumble strips were conducted on a closed roadway surrounding the Kansas Speedway in Kansas City, Kansas, and in a closed park-and-ride parking facility in Lawrence, Kansas. The rumble strips tested in this study were two different types of reusable temporary rumble strips made out of steel with a rubber bottom and four generations of plastic rumble strips. From this study the best solution for most short-term work zones would be the latest generation of plastic rumble strips tested. The earlier generations did not perform as well as the fourth generation especially at 60 mph (96.6 km/hr). The steel rumble strips also hold some promise; however, the structural integrity of the steel rumble strips is an issue that needs to be addressed. [ABSTRACT FROM AUTHOR]

Transverse rumble strips (TRS) have been used by some agencies in rural areas to warn drivers that they are approaching a stop sign. There is some evidence in prior research that TRS are effective in reducing approach speeds. However, little is known about effects on crashes. Data from 20 intersections in Minnesota and 134 intersections in Iowa were used to examine the safety impact of TRS at three- and four-leg intersections with minor-leg stop control. Empirical Bayes methods were incorporated in a before-after analysis to determine the safety effectiveness of the rumble strips. Results from 3- and 4-leg intersections in the combined sample of Iowa and Minnesota indicate about a 21% reduction in fatal, incapacitating injury, and nonincapacitating injury crashes and a 39% reduction in fatal and incapacitating injury crashes. Coupled with this reduction in severe injury crashes, there seems to be an increase in property damage only crashes. A limited economic analysis indicated a reduction in crash harm of about $6,600 per intersection per year due to the installation of TRS. Due to limited sample sizes, no definitive conclusions could be made regarding the specific crash types investigated, that is, right-angle and ran-stop-sign crashes. [ABSTRACT FROM AUTHOR]

Abstract: This research was carried out as part of the French national multidisciplinary research project, PREDIT-SARI. Using a driving simulator, it aimed to test the effectiveness of road treatments intended to inform drivers about the risk of losing control on rural roads with “crest vertical curves” (Landis et al., 2004). [Rosey, F., Auberlet, J.M., Bertrand, J., Plainchault, P., 2008. Impact of perceptual treatments on lateral control during driving on crest vertical curves: a driving simulator study. Accid. Anal. Prev. 40, 1515–1523, Scopus.] used a fixed-base driving simulator to test four perceptual treatments intended to help drivers maintain lateral control when driving on crest vertical curves and found that two of them, rumble strips on both sides of the centerline and sealed shoulders, were more effective than the others. This first study prompted us to ask if non-visual sensory cues (e.g., vestibular or proprioceptive perceptions) could influence driver perception and consequently lateral control. We therefore conducted a second study on a motion-base driving simulator, using the same virtual 3D database. The results showed that: (1) drivers drive closer to the center of their lane when there are rumble strips on both sides of the centerline, or when there are sealed shoulders, than they do with the current marking system (i.e., continuous lines), and (2) the impact of the two tested perceptual treatments was replicated on both types of driving simulator. [Copyright &y& Elsevier]

Abstract: Audio-tactile lane-marking (ATLM) is designed to alert inattentive drivers when they deviate from their lane, and appears to reduce crashes. Research into cognitive-behavioural mechanisms underlying, or possibly undermining, the efficacy of ATLM, is limited. We surveyed 775 randomly selected drivers (42% female, up to 75+ years) regarding the profile line-marking (PLM) employed in Australia (and in some European countries). Respondents perceived advantages of PLM in terms of lane-keeping and visibility. Respondents reported avoiding edge-line PLM, so that it may result in driving too close to untreated centre-line. Findings generally allayed concerns, on the basis of risk homeostasis theory, that PLM may increase risky driving. Perceived efficacy of PLM was not associated with increased drink-driving or speeding, but was associated with increased driving while fatigued. Findings suggest that the efficacy of PLM may be increased by employing PLM on both edge- and centre-lines, by exaggerating the audio-tactile effects of PLM that cause drivers to avoid it, and by discouraging the belief that it is safe to drive while fatigued when PLM is present. [Copyright &y& Elsevier]