Crash Testing and Evaluation of Work Zone Traffic Control Devices

Author(s):  
King K. Mak ◽  
Roger P. Bligh ◽  
Lewis R. Rhodes

Safety of work zones is a major area of concern since it is not always possible to maintain a level of safety comparable to that of a normal highway not under construction. Proper traffic control is critical to the safety of work zones. However, traffic control devices themselves may pose a safety hazard when impacted by errant vehicles. The impact performance of many work zone traffic control devices is mostly unknown, and little, if any, crash testing has been conducted in accordance with guidelines set forth in NCHRP Report 350. The Texas Department of Transportation (TxDOT) has, in recent years, sponsored a number of studies at the Texas Transportation Institute to assess the impact performance of various work zone traffic control devices, including plastic drums and sign substrates, temporary and portable sign supports, plastic cones, vertical panels, and barricades. The results, findings, conclusions, and recommendations are presented for temporary and portable sign supports, plastic drums, sign substrates for use with plastic drums, traffic cones, and vertical panels, whereas those for barricades are covered elsewhere. Most of the work zone traffic control devices satisfactorily met the evaluation criteria set forth in NCHRP Report 350 and are recommended for field implementation. However, some of the devices failed to perform satisfactorily and are not recommended for field applications. The results from these studies are being incorporated into the TxDOT barricade and construction standard sheets for use in work zones.

2002 ◽  
Vol 1797 (1) ◽  
pp. 96-104 ◽  
Author(s):  
Karla A. Polivka ◽  
Ronald K. Faller ◽  
John R. Rohde ◽  
Dean L. Sicking

A variety of traffic-controlling devices are used in work zones; some of these are not normally found on the roadside or in the traveled way outside of the work zones. These devices are used to enhance the safety of the work zones by controlling the traffic through these areas. Because of 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 NCHRP Report 350: Recommended Procedures for the Safety Performance Evaluation of Highway Features. The results of full-scale crash testing of flexible panel work-zone sign stands were evaluated and analyzed to quantify the features that successful devices shared, as well as common features of those devices that failed salient safety criteria. Parameters considered included sign base and upright properties, sign height, cross-member properties, and ancillary details. Results pointed to three problematic, fundamental design issues: ( a) combinations of base and upright stiffness and strength that generally lead to significant windshield damage, ( b) cross members that lead to windshield damage in the end-on (90°) impact orientation, and ( c) appurtenances that have an impact on performance. Although there are a significant number of variables that control the performance of a given device, these generalizations offer a basis for the evaluation of the fundamental design elements.


Author(s):  
Roger P. Bligh ◽  
King K. Mak ◽  
Lewis R. Rhodes

Proper traffic control and delineation are critical to achieving safety in work zones. However, the work zone traffic control devices themselves may pose a safety hazard to vehicle occupants or work crews when impacted by errant vehicles. Thus, there was a need to research the safety performance of work zone traffic control devices to ensure that they perform satisfactorily and meet NCHRP Report 350 guidelines. Several research studies sponsored by the Texas Department of Transportation evaluated the impact performance of various work zone traffic control devices, such as temporary and portable sign supports, plastic drums, sign substrates for use with plastic drums, traffic cones, and vertical panels. Specifically addressed are the studies on barricades. Standard wooden barricade construction was found to be unacceptable due to a demonstrated potential for intrusion of fractured members into the occupant compartment. In response to deficiencies identified in the wooden barricade tests, several alternate barricade designs were developed and successfully tested.


Author(s):  
James E. Bryden ◽  
Laurel B. Andrew ◽  
Jan S. Fortuniewicz

There were 496 work zone traffic accidents on New York State Department of Transportation construction projects from 1994 through 1996. These accidents involved impacts with work zone traffic control devices and safety features; construction features, such as pavement bumps and joints; drainage features; excavations and materials; and construction vehicles, equipment, and workers. These items, which include all of the features introduced into the roadway environment by construction activity, represent one-third of all work zone accidents and 37 percent of those involving serious injury. Channelizing devices, arrow panels, signs, and other traffic control devices generally resulted in little harm when impacted. Impact attenuators, both fixed and truck mounted, also performed well. Although portable concrete barriers prevent vehicle intrusions, impacts with barrier are severe events. Barriers must be properly designed and limited to only those locations where they are needed to protect more serious hazards. Construction vehicles, equipment, and workers were involved in over 20 percent of all work zone accidents, resulting in serious injuries. Although intrusions by private vehicles into work spaces are a serious concern, construction vehicles, equipment, and workers in open travel lanes are also a serious concern. Good design of work zone traffic control plans, combined with adequate training and supervision of workers, is essential to control both concerns.


2021 ◽  
Vol 133 ◽  
pp. 15-26
Author(s):  
Paweł Drózd ◽  
Adam Rosiński

The paper presents the issues of railway traffic control devices testing and focuses on European Train Control System (ETCS) devices widely implemented in railways. The functions of the ETCS system, principles of operation are described. The basic telegrams transmitted in the track-to-train relation are listed. The process of designing and verifying the implemented data and what parameters are checked at the stage of field tests using the locomotive is briefly described. The functional model of the SRK devices, including ETCS elements, was presented, and the close relationship between the base layer of the railway traffic control devices and the ETCS was shown. Equipment testing reduces the availability of the rail network, engages staff, and generates costs. A test generation method is presented to minimize the impact. Two indicators are proposed for reducing the set of checks, the cost of checking and the information effectiveness. The cost of checking due to the problematic estimate is generalized, divided into three groups taking into account the difficulty and resource consumption of bringing the devices to the initial state and their operation according to the test. Therefore, the obtained set of checks is suboptimal and ensures complete coverage of the functions with tests, which is essential when testing devices. The tests are carried out using available setting commands and the implementation of tasks - entry and exit routes at the station. The proposed method is universal and can be applied to any railway traffic control device, regardless of the manufacturing technology. It is a non-invasive method in the structure of the tested devices and does not require additional hardware resources.


Author(s):  
Hoe Kyoung Kim ◽  
Michael P. Hunter

The Manual on Uniform Traffic Control Devices (MUTCD) contains the national standard for installing and maintaining traffic control devices on all streets and highways. The 2003 MUTCD contains numerous corrections, revisions, and updates to the millennium edition (2000). One update is related to the definition of crossing distance at signalized intersections, where the crossing distance is extended to the far-side curb rather than the center of the farthest traffic lane. This study investigated the sensitivity of intersection performance to crossing distance and walking speed, critical constraints in the determination of the minimum green time. Three crossing distance standards and four walking speeds are considered. With Highway Capacity Manual (HCM) procedures, the impacts of the given crossing distance definitions and walking speeds on intersection operations were tested on two intersection configurations over a range of cycle lengths and traffic volumes. The effect on intersection performance was found to be most significant at low cycle lengths, in some instances with the delay increased manyfold. However, when cycle lengths were increased to account for the pedestrian constraints, optimal delay rarely increased by more than a few seconds. Additionally, as the discrepancy between the critical lane traffic volume on the main and cross streets was increased, the impact of pedestrian green times on vehicle delay also increased. It was seen that as the cycle length increased, pedestrian minimum green times no longer governed, so the impact of pedestrians on intersection performance became increasingly insignificant, often with a minimal impact on the optimal performance.


2018 ◽  
Vol 121 ◽  
pp. 411-421
Author(s):  
Paweł Wontorski ◽  
Andrzej Kochan

The article presents the concept of integration system of design automation and system of project management. A model was developed cooperation between the two systems on several levels, based on continuous monitoring of the design process and comparing the assumed values of the selected parameters from the actual values. The selection of variables transmitted based on the assumption of cooperation project management system with the system of design automation for railway traffic control devices, designed to support of designers. Due to the nature of projects for railway traffic control devices drew attention to the quality control of the project in the context of the safety and reliability of railway traffic control system, the impact of deviations from the schedule to the railway timetable, version compatibility, and changes in the chamfering work on objects with continuous rail traffic. The structure of the model is presented in graphical form.


2001 ◽  
Vol 28 (4) ◽  
pp. 747-751 ◽  
Author(s):  
Fazil T Najafi ◽  
Roberto Soares

The objective of this technical note is to discuss the implications related to evaluating work zone user costs. It discusses the work zone dilemma existing among the agency, users, and contractors, and presents different strategies that have been conducted to minimize delay and maximize the number of vehicles that can travel safely throughout the work zone. It further discusses the implication of using five of the most used tools in the process of evaluating the work zone: (i) the Manual on Uniform Traffic Control Devices (MUTCD); (ii) the Highway Capacity Manual (HCM); (iii) computerized software; (iv) delay models; and (v) work zone user costs models.Key words: work zone, user costs, HCM, MUTCD, accident, delay, delay costs.


Author(s):  
Shane M. Farritor ◽  
Mark E. Rentschler

Proper traffic control is critical in highway work zone safety. Traffic control devices such as signs, barricades, cones, and plastic safety barrels are often used. Accidents can occur because of improper work zone design, improper work zone housekeeping, and driver negligence. One solution is to automate safety devices. This paper presents a mobile safety barrel robot. The Robotic Safety Barrels are the first elements of a team of Robotic Safety Markers (RSM) that includes signs, cones, and possibly barricades and arrestors. To be practical the system must be reliable and have a low per robot cost. A robot that malfunctions could enter traffic and create a significant hazard. Also, multiple safety markers are used and barrels are often struck by vehicles. Safety markers with a high replacement cost are not practical. This paper describes the motivation for the robotic safety marker system and how it could improve work zone safety. The design of three robot prototypes is presented. A control architecture is discussed that has been implemented in simulation and partially tested on the prototype robots.


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