PERFORMANCE ANALYSIS OF WELCH PRODUCTS RECYCLED RUBBER SPACER BLOCK

The Midwest Roadside Safety Facility was contracted by Will Stein of the Iowa Department of Transportation to conduct dynamic bogie testing of a recyclable rubber guardrail spacer block manufactured by Welch Products, Inc. The scope of the work included the setup of both a standard, wood guardrail post blockout and the Welch Products recycled rubber blockout on a standard W150x13.5 steel post, as well as two component tests using a bogie vehicle. The bogie tests were conducted in accordance with previously accepted procedures to evaluate the performance of guardrail post blockouts made of non-standard materials

PERFORMANCE ANALYSIS OF WELCH PRODUCTS RECYCLED RUBBER SPACER BLOCK

The Midwest Roadside Safety Facility was contracted by Will Stein of the Iowa Department of Transportation to conduct dynamic bogie testing of a recyclable rubber guardrail spacer block manufactured by Welch Products, Inc. The scope of the work included the setup of both a standard, wood guardrail post blockout and the Welch Products recycled rubber blockout on a standard W150x13.5 steel post, as well as two component tests using a bogie vehicle. The bogie tests were conducted in accordance with previously accepted procedures to evaluate the performance of guardrail post blockouts made of non-standard materials

Safety Performance Evaluation of the Steel Backed Wood Rail to Bridge Rail Transition

The safety performance of the Steel Backed Wood Rail to Bridge Rail Transition was evaluated as part of the federally sponsored Guardrail Testing Program II. During this evaluation, which included 5 full-scale vehicle crash tests, a number of modifications were made to improve the safety of the system. The tests were conducted, reported, and evaluated in accordance with requirements specified for guardrail to bridge rail transitions in the National Cooperative Highway Research Program (NCHRP) Report No. 230, Recommended Procedures for the Safety Performance Evaluation of Highway Appurtenances. Upon implementation of the design changes described herein, the performance of the Steel Backed Wood Rail to Bridge Rail Transition was determined to be acceptable according to these guidelines

Evaluation of the Midwest Guardrail System stiffness transition with curb

A W-beam to thrie beam stiffness transition with a 102-mm (4- in.) tall concrete curb was developed to connect 787-mm (31-in.) tall W-beam guardrail, commonly known as the Midwest Guardrail System (MGS), to a previously developed thrie beam approach guardrail transition system. This upstream stiffness transition was configured with standard steel posts that are commonly used by several state departments of transportation. The toe of a 102-mm (4-in.) tall sloped concrete curb was placed flush with the backside face of the guardrail and extended the length of the transition region. Three full-scale crash tests were conducted according to the Test Level 3 (TL-3) safety standards provided in AASHTO’s Manual for Assessing Safety Hardware (MASH). The first test, MASH Test No. 3-20, was deemed a failure due to guardrail rupture. The stiffness transition was modified to include an additional nested W-beam rail segment upstream from the W-beam to thrie beam transition element. MASH Test No. 3-20 was repeated on the modified system, and the 1100C small car was successfully contained and redirected. During MASH Test No. 3-21, a 2270P pickup truck was successfully contained and redirected. Following the crash testing program, the system was deemed acceptable according to the TL-3 safety performance criteria specified in MASH

A Primer on Vehicle-to-Barrier Communications: Effects of Roadside Barriers, Encroachment, and Vehicle Braking

Today, more than half of the traffic fatalities are a result of run-off-road (RoR) crashes, which usually involve a single vehicle. Roadside barriers are often the last means to mitigate the severity of a RoR crash into hazardous objects or features. While the recent research on vehicular communications primarily focus on safety related wireless communications for vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) scenarios, the interactions between vehicles and barriers in next generation vehicular systems have not been well-studied. In this paper, vehicle-to-barrier (V2B) wireless communication paradigm is introduced as a potential missing link in preventing single-vehicle RoR fatalities1. V2B communications, which take place between vehicles and radios embedded in roadside barriers can contribute to keeping cars on the road and help mitigate RoR crashes. The realization of V2B communication services necessitates an in-depth understanding of the underlying physical characteristics of the environment and channel. To this end, in this paper, some of the first real world field test measurement results of V2B communications are presented. More specifically, the effects of two types of commonly-utilized barriers (rigid concrete barrier and corrugated-beam guardrail) on the V2B channel communications are illustrated. The results show that guardrail barriers exhibit a waveguiding effect on signal transmission, while higher signal attenuation is observed with rigid barriers. Moreover, experiments illustrate the characteristics of V2B orthogonal frequency-division multiplexing (OFDM) communication during vehicle encroachment and braking in terms of received signal strength, error vector magnitude, and phase error statistics. The results highlight that barrier-height antenna deployments result in high channel quality for long distances and are not influenced by mobility and vehicle brake during encroachment scenarios, making them a strong candidate for V2B communications

COMPLIANCE TESTING OF IOWA’S SKID-MOUNTED SIGN DEVICE

A wide variety of traffic control devices are used in work zones, some of which are nont ormally found on the roadside or in the traveled way outsideofthe work zones. These devices are used to enhance the safety of the work zones by controlling the traffic through these areas. Due to the placement of the traffic control devices, the devices themselves may be potentially hazardous to both workers and errant vehicles. The impact performance of many work zone traffic control devices is mainly unknown and to date limited crash testing has been conducted under the criteria of National Cooperative Highway Research Program (NCHRP) Report No. 350, Recommended Procedures for the Safety Performance Evaluation of Highway Features. The objective of the study was to evaluatethe safety performance of existing skid-mounted sign supports through full- scale crash testing. Two full-scale crash tests were conducted on skid-mounted sign supports to determine their safety performance according to the Test Level 3 (TL-3) criteria set forth in the NCHRP Report No. 350. The safety performancevaluations indicate that these skid-mounted sign supports did not perform satisfactorily in the full-scale crash tests. The results of the crash tests were documented, and conclusions and recommendations pertaining tothe safety performance of the existing work zone traffic control devices were made

DEVELOPMENT OF A TL-3 F-SHAPE TEMPORARY CONCRETE MEDIAN BARRIER

A temporary concrete median barrier (CMB) was designed and tested for compliance under the Test Level 3 (TL-3) guidelines specified in the Recommended Procedures for the Safety Performance Evaluation of Highway Features, National Cooperative Highway Research Program (NCHRP) Report No. 350. The barrier is built to the new metric standards and has a traditional pin and loop configuration for interconnection. The objective of this research project was to develop and evaluate a standardized, temporary concrete barrier design while addressing the concerns for safety, economy, structural integrity, constructability, ease of installation, and maintenance. The resulting F-shape barrier segment is 3,800-mm long, a length that reduced the number of connections while limiting the weight of the barriers to ease handling. Full-scale crash testing demonstrated several critical design features. First, the connections need to be tight initially as practicable to limit deformation and rotation of the barriers,. Secondly, the pin needs to restrain the longitudinal barrier forces. Full-scale compliance testing of the final design demonstrated that the barrier was capable of successfully redirecting the 2000-kg vehicle. The vehicle demonstrated significant roll after contact with the barrier, which is evidenced in a majority of other concrete barrier tests. This barrier provides economical work zone protection applicable in a variety of situations, where TL-3 test criteria is warranted

CRASHWORTHY RAILING FOR TIMBER BRIDGES

Bridge railing systems in the United States have historically beers designed based on static load criteria given in the American Association of State Highway and Transportation 0fficials (AASHTO) Standard Specifications for Highway Bridges. In the past decade, full-scale vehicle crash testing has been recognized as a more appropriate and reliable method of evaluating bridge railing acceptability. In 1993, the National Cooperative Highway Research Program published Report 350, Recommended Procedures for the Saftey Performance Evaluation of Highway Features, which provides new criteria for evaluating longitudinal barriers. Based on these specifications, a cooperative research program is continuing between the USDA Forest Service, Forest Products Laboratory, the Midwest Roadside Saftety Facility of the University of Nebraska- Lincoln; and the Federal Highway Administration to develop and crash test bridge railings for wood bridge decks. This paper describes research that resulted in the successful development and testing of several bridge railings for longitudinal and transverse wood decks in accordance with NCHRP Report 350 requirements