Safe Roads

Addressing the Motorcyclist Advisory Council Recommendations: Synthesis on Barrier Design for Motorcyclist Safety

Motorcycle safety, barriers, barrier design

The purpose of roadside barrier systems is to reduce the severity of injuries and number of fatalities by controlling and mitigating crash forces. While barrier systems have been designed and proven to be beneficial for motor vehicles they do not currently address the problems associated with motorcycle crashes. This synthesis of research presented in this report concludes that motorcyclists are more vulnerable than drivers of motor vehicles and that motorcyclists are more likely to be severely injured when they crash into a barrier system. Addressing the challenges associated with barrier systems is critical for reducing the severity of injurious and number of fatalities associated with motorcyclist-barrier crashes. The synthesis report summarized several new barriers and retrofit systems currently used or under development that are specifically intended to improve motorcyclist safety in addition to retaining the existing benefit for motor vehicles. This synthesis report identifies current research proposals and research gaps that should be considered for future research projects. A significant gap is the lack of testing standards and protocols in the United States to verify the safety advantages of roadside barriers for motorcyclists. The final portion of this report summarizes testing parameters to be considered for both upright and sliding impacts into roadside safety. Read the full article

Motorcyclist Advisory Council Recommendations to the Secretary of Transportation and the Federal Highway Administration

Pothole maintenance, open milled road surfaces, raised manhole covers, steel plates, uneven pavement conditions, gravel or debris on roadway, traffic barrel sight criteria, chip sealers, excessive over band crack-fillers and joint sealants, low friction pavement markings, traffic actuated signal detection systems that do not detect a motorcycle are the conditions and specific risk each of them pose to motorcyclists. Read the full article

Groundbreaking Motorcycle Net Containment System for Concrete Barriers

Researchers from the Texas A&M Transportation Institute’s (TTI’s) Roadside Safety and Physical Security Division designed and tested a semi-rigid containment system (a chain-link fence) to help reduce injuries and fatalities. Both simulated and live crash tests were successful with this system. Read the full article

Factors Related to Serious Injury and Fatal Motorcycle Crashes with Traffic Barriers

The project is complete, and publication of the final report is pending. This project is effective 05/01/2009 and the completion date is 11/30/2020. Read the full article

Development and Evaluation of Concrete Barrier Containment Options for Errant Motorcycle Riders

A non-standard upright motorcycle test was performed to evaluate a newly developed chain link fence system for attachment to a concrete barrier. The tested system demonstrated the ability to contain upright errant motorcycle riders while limiting rider injury risks during the impact event. The developed containment system is considered suitable for implementation at locations where an upright motorcycle rider containment option is needed, desired, or both. The system can be retrofitted to existing cast-in-place roadside safety concrete barriers and can be easily adapted for application to concrete profiles differing from the New Jersey shape tested in this research study, such as single slope, vertical, and F-shape profiles. Read the full article

Numerical Simulation of a Motorcycle to Road Barrier Impact

This approach presented design of a roadside barrier with included rollers to transform translational impact energy into rotational energy of the rollers figured out as less effective as intended. The result might be caused by a suboptimal ratio between the moment of inertia of the energy absorbing roller elements and the mass of the motorcyclist. Due to the geometries section, the injury severity concerning the phenomenon of cutting off thereby extremities might be reduced. Read the full article

Investigation of Roadside Barrier Concept to Mitigate Motorcycle Injury in Upright Impact

Finite element computer simulations are a useful tool to assist with the design of roadside safety hardware and with their crashworthiness evaluation. A new motorcycle-friendly barrier concept was investigated to prevent severe injury with upright motorcycle impacts against concrete barriers. Impact simulations were conducted, and the behavior of the motorcycle and rider were analyzed along with injury criteria. Read the full article

Development of a continuous motorcycle protection barrier system using computer simulation and full-scale crash testing

Motorcyclist protectionRoad restraint systemprEN 1317-8SimulationLS-DYNASafety

This paper is intended to provide development and testing details of a versatile and motorcycle friendly continuous motorcycle protection system (CMPS) design. A model of the CMPS design was constructed using finite elements. Results of the study show that newly developed CMPS design is able to satisfy requirements of 60 kph dummy impact, C60, case with minimal risk of injury to motorcyclist. Implementation of CMPS will provide the additional safety required to the existing guardrail designs used at black spots for PTW and areas of with high casualties of PTW. Read the full article

Mean Injury Costs of Run-Off-Road Collisions with Fixed Objects: Passenger Vehicles and Motorcycles

The mean injury costs per casualty collision with concrete barrier, or wire rope barrier were around 1.4 times higher than W-beam. W-beam barrier casualty collisions occurred in all speed zones, nearly two thirds of collisions were located on curves and more than one half were in rural regions. Concrete barrier casualty collisions predominantly occurred in 80 to 90 km/h speed zones and more than two thirds were in metropolitan regions. Wire rope barrier casualty collisions predominantly occurred in 100 km/h or greater speed zones, less than one half were located on curves, and more than three fourths were on highways. W-beams are a more general purpose barrier that are installed in all areas, particularly on low radii curves. Read the full article

Review on Types of Roadside Barriers and Its Influence on Motorcyclists

In the countries like Australia and Germany the injury outcome after full scale crash test for wire rope barrier has been found contradictory to each other and the design of wire rope safety barrier is developed with a view to safety of cars and not to motorcyclists. The impact of rider to the safety barrier sometimes exceeds the safe injury level in India, which can be made safe by design and implementation of wire rope safety barrier. Read the full article

Evaluation of the Motorcycle Blackspot Program

The barrier protection program has been particularly effective in reducing FSI crashes (by 74%), and shows the best economic returns. The long route treatments, the loss-of-control treatments, as well as the intersection treatments have been successful in reducing crashes and show good economic returns. Read the full article

Roadside Safety Design and Devices

The Australian rub-rail device successfully redirected the motorcyclist and prevented a post impact, thereby greatly reducing the injury potential. This study found that the rub-rail will likely prevent serious thoracic injury at all practical impact angles and speeds, and will likely prevent serious head–neck injury at lowimpact angles and higher-impact angles at low speeds. However, the potential for severe head–neck injury exists at high angles and high speeds. Read the full article

MOTORCYCLE CRASHES INTO ROADSIDE BARRIERS STAGE 4: Protecting motorcyclists in collisions with roadside barriers

A steel W-beam barrier with rub-rails is shown to provide lower injury potential to motorcyclists than concrete barriers. Such a system is shown to prevent serious motorcyclist injuries for most practical collision orientations and speeds. A cost-benefit analysis indicates that the implementation of rub-rails to W-beam barriers in a popular motorcycling area are likely to be cost effective in such black spot areas. Read the full article

The Crash Mechanics of Fatal Motorcycle–Barrier Collisions in Australasia

Among the 78 motorcyclists fatally injured in barrier crashes; 77% involved W beams (typically referred to as guardrail in the United States), 10% involved concrete barriers, 8% involved wire rope barriers, and 5% involved other barriers. Other barriers include timber and tubular steel post and beam barriers. Read the full article

Safety Performance of G4 (1S) W-Beam Guardrails versus Cable Median Barriers on Florida’s Freeways

The safety performance of cable median barriers was evaluated using the before-and-after analysis. After the installation of cable median barriers, crash rates of cars and light trucks increased by 36.4% and 21.9%, respectively. On the other hand, a reduction of 59.2% was observed in motorcycle crash rate. Read the full article

Injury typology of fatal motorcycle collisions with roadside barriers in Australia and New Zealand

Sydney, Australia Five types of barriers were compared, and barrier type could not be associated with injury severity with the present dataset, since the crash severity is not uniform across different barrier types. The body regions injured were similar across different barrier types and crash postures, however thorax and pelvis injury had a greater association with sliding crashes than with those in the upright posture. Injury severity (as indicated by the mean Injury Severity Scores (ISS) and maximum Abbreviated Injury Scale (MAIS)) was found to be strongly associated with the pre-crash speed. Read the full article

Motorcycle Crashes into Road Barriers: the Role of Stability and Different Types of Barriers for Injury Outcome

Crash, Injury Risk, Motorcycle, Road Barrier, Stability

The analysis of police records showed no statistically significant difference between the Fatal‐Serious‐Injury (FSI) ratios for wire rope barriers, Kohlswa‐beam and W‐beam barriers, although these FSI‐ratios were generally very high. Injury severity was lower in crashes in which the motorcyclists were in an upright position during the collision. Read the full article

Effect of Barrier Type on Injury Severity in Motorcycle-to-Barrier Collisions in North Carolina, Texas, and New Jersey

This study has presented an analysis of the injury risk in 951 motorcycle–barrier collisions in North Carolina, Texas, and New Jersey. The barriers examined included W-beam guardrails, cable barriers, and concrete barriers. Percentage of people fatally or severely injured were 40.1%, 40.4%, and 36.5% respectively for three barrier types. Read the full article

Fatal Motorcycle-Into-Road-Safety-Barrier Crashes

The number of motorcycle fatalities involving roadside barriers is small at around 15 per year, thus any alterations to roadside safety barriers will have a minor effect on motorcycle fatalities in general. Fatalities of motorcyclists involving impact with a roadside barrier predominantly involved steel W beams. Wire rope barriers were found to have around half the fatality rate of W beam and concrete barriers. In a single-vehicle motorcycle collision with a fixed object, trees and poles were found to be particularly hazardous, and more so than barriers. Read the full article

Characteristics of fatal motorcycle crashes into roadside safety barriers in Australia and New Zealand

MotorcyclesMotorcyclistsFatalitiesRoadside safety barriersW-beamWire-rope cable barriersAustraliaNew Zealand

The roadside barriers predominantly involved were steel W-beams, typically on a bend in the horizontal alignment of the road. Less than 1% of Australian and New Zealand road fatalities involve a motorcyclist striking a barrier. Making crash barriers motorcycle friendly will not reduce motorcycle fatalities significantly. It is unclear whether any changes to barrier engineering design would reduce motorcycle fatalities without compromising other road safety objectives, given that 47.4% of these fatal crashes involved inappropriate riding speeds. Read the full article

Motorcycle crashes into roadside & median road safety barriers

Motorcycle fatalities resulting from roadside barriers crashes are low at around 5-6% which is around 14 per year nationwide of 238 fatalities. Motorcycle guardrail impact 80 times higher risk than car (most dangerous). Motorcycle concrete barrier impact 68 times higher risk than car. Read the full article

Evaluation of 2+1 roads with cable barriers

This report documents the evaluation of 2+1 roads with cable barrier in the median. Fatality risks for motorcyclists have been reduced by 40-50% on 2+1 roads with cable median guardrail barrier. Read the full article

Simulation of motorcycle crashes with w-beam guardrail: Injury patterns and analysis

Potential injury prediction, computer simulation, motorcycle impact with guardrail

This study uses computer simulations to study the impact of a motorcycle with the conventional w-beam guardrail. Impacts at speeds of 32, 48, and 60 km/h, and at an impact angle at 45° are considered. A significant reduction of the severity of injuries was found when the impact speed was reduced from 60 to 32 km/h. In addition to strictly enforcing speed limits, the redesign of the guardrails to be more motorcyclist friendly is required to reduce impact injuries. Read the full article

Overview of Motorcycle Crash Fatalities Involving Road Safety Barriers

Motorcycle Crashes, Roadside Barriers, Wire Rope, W-beam

W-beam steel barriers are overrepresented in fatal motorcycle crashes into roadside barriers. They appear to be particularly hazardous to motorcycle riders. Wire-rope barriers provided a significant benefit to reducing vehicle related crash fatalities in Europe (i.e., Sweden), USA. However, it is still unclear what effect these barriers are having on motorcycle fatalities in Australia. Read the full article

Development of Guidelines for Cable Median Barrier Systems in Texas

Cable Barrier, Wire Rope, Median Barrier, Safety, and Guidelines

The research team found that the subject of motorcycle impacts on cable barrier systems has not received much attention in the United States. There is still no conclusive evidence that cable barrier systems are more hazardous to motorcyclists than any other type of roadside barrier system. Read the full article

Barriers to change: Designing Safe Roads for Motorcyclists

Motorcycle-friendly barrier systems such as secondary rails (metal rails or plastic tubes that fit below the existing barrier), impact attenuators are likely to reduce injury severity. However, the lack of casualty data, evidence of causation and research into the engineering characteristics of such devices, warrants further investigation. Read the full article

Roadside Barriers and Passive Safety of Motorcyclists Along Exclusive Motorcycle Lanes

Passive safety, Guardrail, Simulation, Crash test, Injury

The existing w-beam guardrail system along exclusive motorcycle lanes was originally designed to reduce severity of a crash when cars and trucks involve in run-off road accident – but not specifically to protect motorcyclists during such accident. This study carried out computer simulation of typical crash scenario and conducted a physical crash test to examine motorcyclist interaction with W-beam guardrail. Results confirmed that the existing w-beam guardrail is not safe to motorcyclist, especially for the head injury at impact speed 48km/h and impact angle of 45 degree. Read the full article

Road Safety Devices Assessment for Sliding Motorcyclists Protection

Road safety barriers, Motorcyclists’ protection, Anthropomorphic Test Devices

The device (Sliding Motorcyclists’ Safety Device – SMSD) consists of a metallic laminated installed under the w-system of a flexible barrier by means of spacer meant to absorb most of the impact energy and containing the sliding motorcyclist. It is designed to avoid the impact of the sliding motorcyclist with the barrier posts and, at the same time, to contain the motorcyclist and prevent slides beyond/under the barrier. Read the full article

The Risk of Fatality in Motorcycle Crashes with Roadside Barriers

From 2000-2005, the number of motorcyclists fatally-injured in guardrail crashes increased by 73% from 129 to 224 fatalities. Over two-thirds of motorcycle riders who were fatally injured in a guardrail crash were wearing a helmet. Approximately, one in eight motorcyclists who struck a guardrail were fatally injured – a fatality risk over 80 times higher than for car occupants involved in a collision with a guardrail. Motorcycle based countermeasures being developed by motorcycle manufacturers may provide part of the solution to this problem, but are likely to be of limited success as demonstrated by the failure of helmets to protect completely against fatality. In conjunction with these motorcycle-based countermeasures, there is a critical need to adopt improved barrier designs to protect these vulnerable road users. Read the full article

Design of motorcyclist-friendly guardrail using finite element analysis

Guard-rail design; motorcyclist-friendly; FE simulation; W-beam; crash

The present study has employed polypropylene as material coupled with V-profile rails to give the new guardrail design. Three-dimensional computer models which consist of a newly designed V-beam guardrail and equivalent kinetic characteristics of a motorcycle were developed. The event of collision between the motorcycle and the guardrail was then simulated using computer finite element program, Algor. The results show the newly designed V-beam guardrail has more forgiving and better energy-absorbed characteristics than the existing design the conventional W-beam design. Read the full article

Motorcyclists and Wire Rope Barriers

Whilst there is no clear evidence to suggest that WRSBs are any more dangerous than other barrier types for motorcycles, it is clear that road safety barriers in themselves do provide an obstacle to errant road users – which, depending upon their use and positioning, may result in a worse crash than if they had otherwise not been provided. It is true to note that different barriers have different performance characteristics and that achieving optimal safety outcomes depends on determining the need for the barrier as well as selecting the appropriate type of barrier for the site conditions. Read the full article

Guidelines for PTW-Safer Road Design in Europe

Limited research done so far does not warrant the conclusion that cable barriers are more hazardous than other types of barrier. The use of a Powered Two Wheelers (PTW)-friendly safety barrier system should be considered in places, for example in bends, where motorcyclists will be most at risk. The general principle of a PTW-friendly safety barrier is to protect the fallen motorcyclist from jutting support posts. These PTW-friendly safety systems may be newly installed or fitted on existing barriers. Other possibilities are using round posts instead of those with sharp edges or using crash barrier protection. Read the full article

Motorcycle impacts into roadside barriers–real-world accident studies, crash tests and simulations carried out in Germany and Australia

A modified roadside guard rail system made from steel with respect to better protection for impacting motorcyclists was proposed. The computer simulation results revealed that the risk for motorcyclists of being injured when colliding with either a wire rope or a concrete barrier will be high compared to the new modified roadside guard rail protection system. Read the full article

Ameliorating Motorcyclist Injury Risk from Flexible Barrier Collisions in Victoria

Moto.Tub and Crash Barrier Post Protectors are currently two devices that can quite readily be integrated into barrier design to help alleviate motorcyclist injury risk in flexible barrier collisions, as well as motorcyclist safety concerns. Read the full article

The Influence of Wire Rope Barriers on Motorcyclists

This study and statistical data showed that on roads with wire rope barriers, motorcycle speeds are rather concentrated around the speed limit. In addition, on equivalent roads without barriers, motorcycle speeds were rather spread out and, in many cases, either substantially exceeded the speed limit or were much below it. On the other hand, nearly three quarters of interviewed motorcyclists stated that barriers had no influence on their speed. Read the full article

Flexible Barrier Systems Along High-Speed Roads – a Lifesaving Opportunity

Swedish results indicate that in over 600 km of flexible barrier, no death has occurred as a direct consequence of a barrier impact and severe injuries have significantly reduced. Existing infrastructure allows the introduction of flexible barriers along the roadsides and centre with minimal modification, hence providing a significant cost advantage. Although some concern has been expressed regarding the use of flexible barriers and its potential to cause injury to motorcyclists who impact with them, no evidence exists to indicate that riders who leave the roadway will be at greater risk of injury striking a flexible barrier than if there were either no barriers or barriers of a different type. Read the full article

Motorcycle and Safety Barrier Crash-Testing: Feasibility Study

Safety barrier, crash-test, motorcycle, impact, occupant protection

The literature suggests that the most dangerous aspect of guardrails with respect to motorcyclists is exposed guardrail posts. In addition, the jagged edges of wire mesh, or wire mesh topped barrier systems provide numerous lacerating surfaces which serve to accentuate rider injury risk. Barrier systems of insufficient height can also pose a threat to riders as they can be catapulted over the top of barrier systems. Alternatively, barrier systems such as W-beam barriers and wire rope safety barriers that leave a space between the road surface and the bottom of the barrier, potentially allow riders to slide under the barrier into contact with roadside hazards. Rigid barriers cause the rider to absorb virtually all of the kinetic energy at impact thus increasing injury risk for riders, particularly as the impact angle increases. Read the full article

Motorcycle Impacts with Guardrails

France A guardrail with two beams was designed and tested in order to avoid the posts motorcyclists’ impacts. Tests were performed with a dummy ejected from a sled. The deceleration levels registered on different parts of the dummy were acceptable. Tests with cars were conducted to confirm this model. Read the full article

Improved Design of Motorcycles and Road Barriers can Save Lives

The crash tests showed that the Motorcyclist Protection Systems (MPS) is beneficial even in upright collisions, as it can make the lower side of the barrier smoother and softer, thus reducing the risk that the front wheel, other motorcycle parts or the rider’s leg get stuck into the lower posts. A smoother and softer barrier (with MPS and a prototype top protection) was crash tested in combination with a motorcycle fitted with a boxer engine. This combination significantly reduced the injury risks. Read the full article

Environmental Hazards in Motorcycle Accidents

Many barrier systems on curved bridges such as freeway connectors are designed to restrain an automobile, and they do a good job of restraining motorcycles. But they are too low to prevent the motorcycle rider from going over the edge to almost certain death. The requirements for prevention of these incidents are simple: a smooth protective barrier that rises to a little higher than the rider center of mass (to perhaps 4½ feet) will suffice. The most obvious candidates for their use would be urban freeway interchanges and elevated off-ramps. Read the full article

Addressing the Motorcyclist Advisory Council Recommendations: Synthesis on Roadway Geometry, Pavement Design, and Pavement Construction and Maintenance Practices

Motorcycle safety, roadway geometric design, pavement friction, construction, maintenance

Roadway geometry, pavement design, and pavement construction and maintenance practices are designed to construct and maintain roadway facilities that provide for motor vehicle travel. Typical practices focus on passenger car or truck needs and may not specifically recognize the special needs of motorcycles. This synthesis highlights the general recent history of motorcycle-specific safety research while also addressing specific road design, pavement design, and construction and maintenance issues related to motorcycles. Significant gaps in design, friction needs, and motorcycle-specific concerns related to roadway and pavement construction and maintenance are identified. The final portion of this report summarizes potential research topics that could be investigated to help improve the safety of both motorcycle travel and all other types of motor vehicle travel in the United States. Read the full article

Motorcyclist Advisory Council Recommendations to the Secretary of Transportation and the Federal Highway Administration

Pothole maintenance, open milled road surfaces, raised manhole covers, steel plates, uneven pavement conditions, gravel or debris on roadway, traffic barrel sight criteria, chip sealers, excessive over band crack-fillers and joint sealants, low friction pavement markings, traffic actuated signal detection systems that do not detect a motorcycle are the conditions and specific risk each of them pose to motorcyclists. Read the full article

Motorcycle Road Safety Audit Case Studies

Road safety audit, motorcycles, roadway design, safety

Road Safety Audits (RSAs) are a formal safety performance examination of an existing or future roadway or off-road facility and are conducted by an independent, experienced, multidisciplinary team. This case study document provides a review of the RSA process and three case study examples of RSAs that had a demonstrated high-frequency of crashes involving motorcyclists. The case studies include photographs, a project background, and key RSA findings and suggestions. These case studies will help Federal, State, Tribal, and local agencies better understand conditions that affect motorcyclists and how to effectively address safety in the RSA process. Read the full article

Motorcycle Crash Causation Study: Final Report

Motorcycle, Motorcycle crashes, Hurt Report, Motorcyclist, Motorcycle rider, OECD, Motorcycle crash causation, Crash data, Motorcycle crash investigation

This large-scale study, based on the Motorcycle Crash Causation Study (MCCS) sponsored by the National Highway Traffic Safety Administration, gathered data on motorcycle (MC) crashes by intensive post-crash investigations and control MC observations and interviews conducted in Orange County, CA. The study developed a dataset that researchers can use to investigate additional research questions. The database provides data from 351 injury crashes and 702 paired control observations. Of the crashes observed, 82 were single-vehicle crashes, and 269 were multiple-vehicle crashes, all of which involved a total of 294 other in-transit vehicles and 11 parked vehicles; 40 crashes resulted in fatalities, with 22 single vehicle–crash fatalities and 18 multiple vehicle–crash fatalities observed. The study compiled the observations on rider, passenger, and other-vehicle (OV) driver demographics; environmental factors; factors contributing to the crash; MC; and OV parameters; injuries sustained; and clothing/safety equipment used. The study also compiled observations on the crash and control riders, passengers, and MCs and OVs involved in the crashes. Within the crash observations, the study compiled and compared the data for single- and multiple-vehicle crashes, fatal and nonfatal crashes, along with selected previous studies and elements of the National Automotive Sampling System/General Estimates System and the Fatality Analysis Reporting System databases. The data are available in SAS® and Microsoft® Excel™ formats; MCCS Volume 2 defines all codes used. Read the full article

Infrastructure Countermeasures to Mitigate Motorcyclist Crashes in Europe

Behavioral safety, helmet law, licensing law, motorcycle safety, motorcyclist fatalities, powered two wheeler, roadside barriers

The number and rate of motorcyclist deaths on U.S. roads are rising dramatically. The Federal Highway Administration, American Association of State Highway and Transportation Officials, and National Cooperative Highway Research Program sponsored a scanning study of five European countries to evaluate infrastructure improvements to aid motorcyclists. The scan team found that the types of infrastructure safety improvements used in Europe, with the exception of motorcycle-friendly roadside barriers, were those that generally improved safety for all vehicle classes. The biggest differences the team observed were in behavioral safety, helmet laws, training, and licensing. The team also noted great cooperation between road authorities and stakeholder groups representing motorcycle riders. Team recommendations for U.S. implementation include filling in knowledge gaps to improve motorcycle safety, conducting research on motorcycle infrastructure safety, and updating design guidelines to accommodate motorcyclist safety. Read the full article

Leading Practices for Motorcyclist Safety

The scan team gathered information on a broad array of topics and identified some effective practices that could be adopted at the state, city, and county levels. The team strongly endorses the concept of a motorcycle safety coalition in each state, with a membership representative of all stakeholders in the state. The coalitions provide perspective on the unique riding and handling characteristics of motorized two- and three-wheeled vehicles that are affected by roadway design, construction, and maintenance practices. The most effective coalitions serve as advisory bodies to heads of transportation departments. Formal business plans and frequent, regularly scheduled meetings provide opportunities for timely feedback on current and emerging safety issues. These advisory groups are effective in raising awareness of motorcycling issues among transportation officials, engineering and maintenance personnel, and the traveling public. Read the full article

Recording and evaluating motorcyclists’ gaze behaviour in rural roads

Riding distraction, motorcyclists, naturalistic research, road safety

Advertising related elements and other unrelated to the driving task elements on the road attract driver’s attention for time intervals greater than the ones derive from driving related elements. More work has to be made in adverting related legislation in order to eliminate road visual pollution and prevent future motorcycle accidents. Read the full article

Study on Motorcycle Safety in Negotiation with Horizontal Curves in Florida and Development of Crash Modification Factors

• Share curve (R<1500ft) increases crash frequency and severity; increased curve radius, advance curve/speed warnings, Chevrons & enhanced chevron signs, Dynamic curve warning system are suggested;
• Reverse Curve decreased crash frequency but increases severity; Reverse curve warning & advisory speed signing, chevrons & enhanced chevron signs, flashing beacons are suggested;
• Auxiliary lane increases crash frequency but decreases severity; Longitudinal channelizers, pavement marking are suggested;
• Surface (shoulder) width increases crash severity; Road markings that make road look narrower (e.g., chevron markings, transverse shoulder stripes) is suggested;
• Rough (poor) pavement decreases crash severity; Road markings that make road look rougher, transverse rumble strips are suggested;
• Lighting decreases crash severity; Lighting installment (e.g., in-pavement lighting, reflective barrier delineation) is suggested.

Read the full article

Identifying Infrastructure-Based Motorcycle-Crash Countermeasures: Phase I Final Workshop Finding Report

Motorcycle safety, motorcyclist fatalities, infrastructure-based countermeasure

Researchers provided the results of the countermeasure prioritization ranking to FHWA. Using an internal process, FHWA reviewed and modified the ranking. This activity resulted in the ranking of five countermeasures from highest to lowest with the highest countermeasure indicative of those to consider for future research.

1. High-friction surface treatment & textured pavement markings;
2. Limited-sight-distance warning signs at segments and intersections;
3. Pavement-change warning sign;
4. Curve-speed warning signs;
5. Prohibitive signs (i.e., stop sign, no-left-turn sign

Read the full article

Emerging Practices for Addressing Motorcycle Crashes at Intersections

Motorcycles, intersections, data collection, crash data, infrastructure treatments

High friction surface treatment (HFST). HFST can be applied quickly and is a moderate-cost countermeasure. Previous research has shown HFST to be effective in reducing crashes. It stands to reason that the effectiveness would extend to motorcycle crashes specifically. Read the full article

Improving Motorcycle Safety by Enhancing Roadway Design

State Practices:

• Use of advance warning signs and pavement markings
• Removal of roadway debris & loose gravel
• Roadway safety inspections or audits
• Involve motorcyclists in the new designs, treatments, and materials

Read the full article

Modeling Safety Effects of Horizontal Curve Design on Injury Severity of Single-Motorcycle Crashes with Mixed-Effects Logistic Model

Horizontal curve radius and type have significant influence on the injury severity of single-motorcycle crashes. Compared with flat curves (radius ≥ 4,000 ft), sharp curves (radius < 1,500 ft) are likely to increase the probability of severe injury (fatality and incapacitating injury) by 7.7%. Reverse curves, on average, tend to increase the probability of severe injuries by 5.82%. Read the full article

Safety effects of horizontal curve design on motorcycle crash frequency on rural, two-lane, undivided highways in Florida

Horizontal curve radius significantly influences motorcycle crash occurrence on rural, two-lane, undivided roads. The presence of auxiliary lanes, vertical slope, high access density, and growth of annual average daily traffic could increase the number of motorcycle crashes significantly. Read the full article

Characterization of roadway geometry associated with motorcycle crashes into longitudinal barriers

Motorcycle; traffic barriers; roadway geometry; curvature; grade

Compared to all other single vehicle motorcycle crashes, motorcycle impacts with barriers were found to be significantly more likely on smaller radius horizontal curves, sections with grade in excess of 3%, non-intersection locations and sections with posted speeds greater than 45 mph. Roadway sections with these characteristics may be good candidates for motorcycle-to-barrier countermeasures in the absence of other more region-specific crash data. Despite similar trends in both states with regard to roadway alignment for this crash type, however, large differences were found in several roadway characteristics including area type (e.g., rural/urban), functional classification, number of lanes, shoulder width, and configuration (e.g., divided/undivided). As such, the most effective countermeasure installations will likely differ depending on the specific motorcycle-to-barrier crash experience in a given state and/or region. Read the full article

Influence of horizontally curved roadway section characteristics on motorcycle-to-barrier crash frequency

Motorcycle crashLongitudinal barriersHorizontal curvesRoadway characteristics

The developed model results suggested isolated curves, decreases in curve radius, increases in traffic volume, and increases curve length increased the risk of motorcycle-to-barrier crashes on a given horizontal curve section. The strongest predictor of crash frequency was found to be curve radius which supports a motorcycle-to-barrier crash countermeasure placement criterion based, at the very least, on horizontal curve radius. With respect to the existing horizontal curve criterion of 820 feet or less, curves meeting this criterion were found to increase crash frequency rate by a factor of 10 compared to curves not meeting this criterion. Curves with radius less than 500 feet were found to be more than 40 times more likely to experience a motorcycle-to-barrier crash than a curve with radius in excess of 2800 feet. Given curves of identical radius, the model results also suggested that longer curves, those with higher traffic volume, and those that have no adjacent curved sections within 300 feet of either curve end would likely be better candidates for a motorcycle-to-barrier crash countermeasure. Read the full article

Improving Safety for Motorcycle, Scooter and Moped Riders

The road environment has a significant influence on the risk of crashes involving PTWs. Contributing factors include: road surface defects (such as roughness, potholes or debris on the road); presence of slippery material (water, oil) on the road; broad line markings or use of raised pavement markers; poor road alignment; presence of obstacles, roadside hazards and safety barriers, and interactions with other road users (including heavy vehicles, cars, cyclists, pedestrians and other PTWs). Read the full article

Investigation Motorcycle Safety at Exit Ramp Sections by Analyzing Historical Crash Data and Rider’s Perception

Motorcycle Safety; Exit Ramp Configurations; Crash Modeling; Riders’ Survey

If all of the selected variables remain the same, a directional exit, loop exit, or outer connection exits will have 16%, 27%, and 42% more crashes than a diamond exit. Enhancing speed enforcement, limiting, and reducing sharp curves, providing proper warning, or conducting outreach to both motorcycle riders and car drivers might be efficient ways to make exits safer. Selecting optimal ramp terminal types, control types (signalized/stop signs), and improving secondary street geometrics can be expected to improve motorcycle safety. Read the full article

A segment level analysis of multi-vehicle motorcycle crashes in Ohio using Bayesian multi-level mixed effects models

Hierarchical Bayes, Spatial random effects, Uncorrelated random effects, Negative binomial model, Conditional autoregressive distribution, Mixed effects

Widening shoulders up to eight-feet or widening lanes up to 11-feet may be a more justifiable approach for crash mitigation. Read the full article

Effects of Horizontal Curvature on Single-Vehicle Motorcycle Crashes along Rural Two-Lane Highways

Longer, high-speed curves and sharper curves with smaller design radii are both found to increase the probability of motorcycle crashes occurring on a roadway segment. Collectively, these results highlight the importance of designing curves that are conducive to safe motorcycle usage, through a larger design radius, larger shoulders, and other factors. Read the full article

Effects of Center-Line Rumble Strips on Non-Conventional Vehicles

This study gave no evidence that the rumble strips pose a safety hazard to motorcycles or 2-wheel motorcycles. Continuing to install them on rural highways should not be impeded by concerns over motorcycles. If there is any additional risk caused by them, it is small enough to be offset by the established benefits. It is recommended that new cyclists become aware of the rumble strips early in their experience. Including rumble strips in motorcycle safety courses and possibly riding examinations can insure riders are not alarmed in their first encounters. Read the full article

Motorcyclist Advisory Council Recommendations to the Secretary of Transportation and the Federal Highway Administration

Pothole maintenance, open milled road surfaces, raised manhole covers, steel plates, uneven pavement conditions, gravel or debris on roadway, traffic barrel sight criteria, chip sealers, excessive over band crack-fillers and joint sealants, low friction pavement markings, traffic actuated signal detection systems that do not detect a motorcycle are the conditions and specific risk each of them pose to motorcyclists. Read the full article

Improving Motorcycle Safety by Enhancing Roadway Design

State Practices:

• Use of advance warning signs and pavement markings
• Removal of roadway debris & loose gravel
• Roadway safety inspections or audits
• Involve motorcyclists in the new designs, treatments, and materials

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Infrastructure Improvements to Reduce Motorcycle Casualties

Motorcycle, motorcycle crash, motorcycle crash prevention, motorcycle infrastructure, motorcycle treatments, motorcycle safety, road safety

The main cost-effective measures are roadside hazard management, surface rehabilitation (skid resistance, road surface improvements), delineation improvements (especially on curves), sight distance improvements (midblock), lane and shoulder widening and improvements to intersection quality (layout, sight lines, signage and delineation). Read the full article

Motorcycle safety route review: a case study

Safe systems, motorcycles, crash rates, speed, signage, awareness

The main focus of the strategy was on lower, more cost-effective treatments that could be implemented in a short time frame including speed zone reductions, additional police enforcement, upgrading and improving signposting linemarking and delineation and awareness campaigns to reinforce safety messages to motorcyclists. Read the full article

Roadway Factors Associated with Motorcycle Crashes

The study results indicate that the main roadway elements associated with motorcycle crash rates are the cross-section type and width, the intersection density, the posted speed limit, the presence of on street parking, pavement defects, and residential developments. These roadway elements and conditions can be targeted on new road construction and roadway improvement projects, in which motorcycles are considered in the road design. Establishing effective road maintenance practices that focus on these particular roadway elements can alleviate the problem of motorcycle crashes. Read the full article

Guidelines on Motorcycle and Bicycle Work Zone Safety

Recommended practices:

1. Implement standards which reduce the height of vertical pavement edges on or near roadway surfaces that are open to moving to traffic;
2. For temporary median crossovers and other temporary changes to horizontal alignment, avoid using design speeds that are more than 10 mph below the existing design speed of the roadway
3. Specify motorcycle related static warning sing use in advance of identified pavement degradations and other features that could cause a hazard;
4. When additional visibility and attention to work zone hazards are needed, use motorcycle-targeted warning messages on portable changeable message signs (PCMS);
5. Implement practices to mitigate edge transitions and other temporarily elevated obstructions on roadways;
6. Be aware of motorcycle concerns when using pavement marking that are in-lane or that cross the travel path;
7. Incorporating motorcycle hazards and recommended practices into agency project design traffic manuals, and contract documents;
8. Increase the emphasis of continuous pavement condition monitoring by project inspectors and maintenance supervisors.

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IHIE Guidelines for Motorcycling – Improving safety through engineering and integration.

Factors affecting motorcyclists include skid resistance; surface contamination and debris; drainage gullies; utility covers; road markings and road studs. All of which should be considered from a motorcycle-inclusive viewpoint. Similarly, poorly installed or maintained bridge joints, especially longitudinal ones, which can act like tramlines to motorcycle wheels, need to be maintained adequately. A focus on planned maintenance that accounts for the needs of motorcyclists will always be more desirable than even the best reactive fault-reporting system. Read the full article

National Agenda for Motorcycle Safety Implementation Guide

• Maintenance – Reduce roadway debris; remove slippery sealants and road repair substances;
• Education – Educate road design and maintenance personnel about conditions that pose hazards to motorcycle operators;

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Work Zone Traffic Control Guidelines for Maintenance Operations

Additional warning signs (i.e., “Motorcycles Use Extreme Caution”) may need to be added to a plan to address specific work zone conditions when they exist. Read the full article

Study on Motorcycle Safety in Negotiation with Horizontal Curves in Florida and Development of Crash Modification Factors

Full access control decreases both crash frequency and severity; Enforcement countermeasure (e.g., helmet use) is suggested. Read the full article

Traffic Safety Messages on Dynamic Message Signs (DMS)

Several states have started to display their state-specific number of traffic fatalities year-to-date on DMS. Several studies showed that there could be changes in driver behavior by posting safety messages on DMS; some also included small samples of traffic data analysis, which showed some speed changes when the drivers approached active DMS. Overall, the findings from this report support the use of DMS to disseminate highway safety messages. However, more research is needed to validate the perceptions noted in the surveys and more field studies are necessary to confirm long-term impacts of using DMS to convey safety messages about driver behavior and traffic safety. Read the full article

Emerging Practices for Addressing Motorcycle Crashes at Intersections

Motorcycles, intersections, data collection, crash data, infrastructure treatments

The project team developed a list of infrastructure treatments with likely motorcycle safety benefits. Many of the treatments reduce the types of crashes that occur at intersections that often involve motorcycles.

1. Flashing yellow arrow (FYA) that provides a protected, followed by permissive left-turn movement at signalized intersections aims to reduce crashes between left-turning and opposing through movement vehicles;
2. Signal loop adjustments. Increasing the sensitivity of loop detectors for proper motorcycle detection may reduce the likelihood of motorcycles entering an intersection against a red light and the corresponding safety risks;
3. Permanent motorcycle warning signs installation. A perceived increase of driver awareness of motorcycles at intersections would likely improve safety;
4. Intersection Conflict Warning System (ICWS). Implementing an ICWS treatment has shown positive results in other studies for crashes involving all motor vehicle types.

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Transport for London Urban Motorcycle Design Handbook

Motorcyclists face a wide range of design issues and challenges, the previous section identified the five that matter most to motorcyclists, these being:

• Factors affecting grip;
• Visibility;
• Road-side features;
• Traffic calming (i.e., Speed cushions); and
• Filtering.

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Infrastructure Countermeasures to Mitigate Motorcyclist Crashes in Europe

Behavioral safety, helmet law, licensing law, motorcycle safety, motorcyclist fatalities, powered two-wheeler, roadside barriers

In several countries, the team observed lighter weight lattice sign posts, which were believed to be less of an injury threat to motorcyclists. In Germany, a road improvement project suggested using flexible bollards or pylons in place of post-mounted delineators or chevron signs in curves. One practice observed in Belgium and elsewhere was to leave a gap in the marking material so that motorcyclists could thread through the marking without encountering the change in friction. Read the full article

Right-Angle Crash Vulnerability of Motorcycles at Signalized Intersections: Mixed Logit Analysis

The findings related to the use of red-light cameras at intersections show that they are effective in reducing the vulnerability of motorcyclists. The provision of protected right-turn phases at sites with high motorcycle traffic may be an effective intervention measure. Furthermore, at sites with high motorcycle presence, implementing a system of actuated signal control to include a protected right-turn phase may be a cost-effective countermeasure. Another potential countermeasure is to develop an intelligent system of electronic warning message signs to alert drivers of any oncoming motorcycles. Read the full article

IHIE Guidelines for Motorcycling – Improving safety through engineering and integration.

Factors affecting motorcyclists include skid resistance; surface contamination and debris; drainage gullies; utility covers; road markings and road studs. All of which should be considered from a motorcycle-inclusive viewpoint. Similarly, poorly installed or maintained bridge joints, especially longitudinal ones, which can act like tramlines to motorcycle wheels, need to be maintained adequately. A focus on planned maintenance that accounts for the needs of motorcyclists will always be more desirable than even the best reactive fault-reporting system. Read the full article

National Agenda for Motorcycle Safety Implementation Guide

Signage – Post specific warnings for motorcycle operators where hazardous conditions exist. Read the full article