Improving Work Zone Safety Through Speed Management

Improving Work Zone Safety Through Speed Management PDF Author: Norman M. Sommers
Publisher:
ISBN:
Category : Road work zones
Languages : en
Pages : 78

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Book Description
Safety hazards are increased in highway work zones as the dynamics of a work zone introduce a constantly changing environment with varying levels of risk. Excessive speeding through work and maintenance zones is a common occurrence which elevates the dangers to both drivers and motorists in the work zone. Although most work zones are controlled by reduced speed limits or state law enforcement, driver adherence to these regulations and laws in very minimal, especially in work zones. Several studies have shown a correlation between speeding in work zones and traffic crashes which lead most traffic safety professionals to conclude that excessive speeding and speed variance are the contributing factors in a large percentage of traffic crashes, injuries or fatalities. The most influential factor in achieving speed compliance in the work zone is the driver's perception of heightened risk. The main objective of this study was to determine the safest and most effective countermeasure for the reduction of vehicular speeds within construction and maintenance work zones. The purpose of the simulator experiment was to determine the effectiveness of 20 countermeasures on the reduction of speed through work zones in a controlled laboratory setting. The literature review identified several past research studies utilizing speed reduction countermeasures in work zones and under normal traffic conditions. From this review, 20 countermeasures were selected for evaluation based upon discussions with ODOT personnel.The post hoc tests indicated that the presence of construction workers, presence of construction vehicles, law enforcement, speed photo enforcement and shifting lanes were most effective at reducing speeds in work zones. The least effective speed reduction countermeasures included 3 sets of 3 rumble strips, concrete barriers, other channelizing devices and changeable message signs with speed reductions less than 10 mph.

Improving Work Zone Safety Through Speed Management

Improving Work Zone Safety Through Speed Management PDF Author: Norman M. Sommers
Publisher:
ISBN:
Category : Road work zones
Languages : en
Pages : 78

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Book Description
Safety hazards are increased in highway work zones as the dynamics of a work zone introduce a constantly changing environment with varying levels of risk. Excessive speeding through work and maintenance zones is a common occurrence which elevates the dangers to both drivers and motorists in the work zone. Although most work zones are controlled by reduced speed limits or state law enforcement, driver adherence to these regulations and laws in very minimal, especially in work zones. Several studies have shown a correlation between speeding in work zones and traffic crashes which lead most traffic safety professionals to conclude that excessive speeding and speed variance are the contributing factors in a large percentage of traffic crashes, injuries or fatalities. The most influential factor in achieving speed compliance in the work zone is the driver's perception of heightened risk. The main objective of this study was to determine the safest and most effective countermeasure for the reduction of vehicular speeds within construction and maintenance work zones. The purpose of the simulator experiment was to determine the effectiveness of 20 countermeasures on the reduction of speed through work zones in a controlled laboratory setting. The literature review identified several past research studies utilizing speed reduction countermeasures in work zones and under normal traffic conditions. From this review, 20 countermeasures were selected for evaluation based upon discussions with ODOT personnel.The post hoc tests indicated that the presence of construction workers, presence of construction vehicles, law enforcement, speed photo enforcement and shifting lanes were most effective at reducing speeds in work zones. The least effective speed reduction countermeasures included 3 sets of 3 rumble strips, concrete barriers, other channelizing devices and changeable message signs with speed reductions less than 10 mph.

Work Zone Speed Management

Work Zone Speed Management PDF Author: John W. Shaw
Publisher:
ISBN:
Category : Road work zones
Languages : en
Pages : 152

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Book Description
This synthesis documents information regarding the current state of practice for work zone speed management. The report compiles data, procedures, techniques, and technical issues related to observing and comparing work zone speeds. The speed management measures have been organized into four categories: engineering, operational, enforcement, and public education and outreach. Information included in this study was acquired through a review of the literature, two surveys of state department of transportation representatives in all states, a compilation of state agency public information campaigns, and follow-up interviews with select survey respondents from several U.S. states and one Canadian province.

Mobility and Safety Evaluation of Integrated Dynamic Merge and Speed Control Strategies in Work Zones

Mobility and Safety Evaluation of Integrated Dynamic Merge and Speed Control Strategies in Work Zones PDF Author: Syed Muhammad Zaier Abbas Zaidi
Publisher:
ISBN:
Category : Intelligent transportation systems
Languages : en
Pages : 192

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Book Description
In recent years, there has been a considerable increase in the amount of construction work on the U.S. national highways. Most of the work undertaken is the reconstruction and rehabilitation of the existing transportation networks. Work zones in the United States are likely to increase in number, duration and length due to emphasis on repair and highway reconstruction as a significant portion of all federal-aid highway funds are now geared toward highway rehabilitation. The challenge of mobility is particularly acute in work zone areas as road repair and construction intensifies traffic issues and concentrates them in specific locations and at specific times. Due to the capacity drop, which is the result of lane closure in work zone area, congestion will occur with a high traffic demand. The congestion increases number and severity of traffic conflicts which raise the potential for accidents; furthermore traffic operational properties of roadway in work zone area become worse. Intelligent Transportation System (ITS) technologies have been developed and are being deployed to improve the safety and mobility of traffic in and around work zones. In several states in the US, the use of Dynamic Merge Controls also known as Dynamic Lane Merge (DLM) system has been initiated to enhance traffic safety and to improve traffic flow in work zone areas. The DLM usually takes two forms; dynamic early merge and dynamic late merge. The use of variable speed limit (VSL) systems at work zones is also one of those measures. VSL systems improve safety by helping the driver in determining the maximum speed that drivers should travel. Besides adding improvement to safety, they are also expected to improve mobility at the work zones. The main goal of this study is to evaluate the safety and operational effectiveness of the dynamic merge systems i.e. the dynamic early lane merge and dynamic late lane merge, in the presence of VSL system. More specifically, the VISSIM model is utilized to simulate a two-to-one lane configuration when one out of the two lanes in the work zone is closed for traffic. Six different scenarios were adopted to assess the effectiveness of these scenarios under different traffic demand volumes and different drivers' compliance rates to the messages displayed by the systems. These scenarios are; [bullet] Work Zone without VSL and without SDLMS or the current Motorist Awareness System (MAS) [bullet] Work Zone with VSL and without SDLMS [bullet] Work Zone with VSL and Early SDLMS [bullet] Work Zone with VSL and Late SDLMS [bullet] Work Zone with early SDLMS and without VSL [bullet] Work Zone with early SDLMS and without VSL An already calibrated and validated VISSIM model for Simplified Dynamic Lane Merge System (SDLMS) in accordance with the real life work zone was modified with a VSL through Vehicle Actuated Programming (VAP) code. Three different logics were coded each for VSL alone, early SDLMS+VSL and late SDLMS+VSL. All these logics were fine tuned with several test runs before finalizing it for the final simulation. It is found through the simulation of above mentioned scenarios that for low and medium volume levels (V0500, V1000 and V1500), there is no significant difference between the Maintenance of Traffic (MOT) plans for mean throughputs. However, for higher volume levels (V2000 and V2500), late SDLMS with and without VSL produced higher mean throughputs for all compliance rates and truck percentages except when the demand volume was 2,500 vph and compliance of 60%, where it produces the significantly lower mean throughputs. In terms of travel time through the work zone, results indicated that there is no significant difference between MOT types for demand levels of V0500 and V1000 when compliance is 40% or less but for compliance of 60% and more, only demand volume level that is not significantly different from other MOT types is V0500. This study revealed that VSL increases travel time through the work zone. This might be due to non-compliant vehicles that follow the compliant vehicle ahead unless they find a sufficient gap in adjacent lane to pass the compliant vehicle. It is also found out that VSL makes the system safer at higher volumes (2,000 vph and 2,500 vph). This was observed through safety surrogate measures selected for this study. Another outcome of this study is that the addition of VSL to the dynamic merge systems helps in improving the overall safety of the system by lowering speed variances and deceleration means of the vehicles travelling through the work zone. The passage of traffic through the work zone is made safer when a speed control is integrated to a dynamic merge system. It can be inferred from the simulation results that integrated SDLMS and VSL systems have better performance in terms of traffic mobility and safety than existing individual controls and also show that the integrated SDLMS and VSL system has more potential than each individual systems.

Improving Safety in High-Speed Work Zones: A Super 70 Study

Improving Safety in High-Speed Work Zones: A Super 70 Study PDF Author: Andrew P. Tarko
Publisher: Purdue University Press
ISBN: 9781622600021
Category :
Languages : en
Pages : 80

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Book Description


Strategies for Work Zone Transportation Management Plans

Strategies for Work Zone Transportation Management Plans PDF Author: Leverson Boodlal
Publisher:
ISBN: 9780309481786
Category : Road work zones
Languages : en
Pages : 0

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Book Description
One of the ways a state department of transportation or other transportation agency can address work zone safety and other impacts is to develop and implement a Transportation Management Plan (TMP). The TRB National Cooperative Highway Research Program's NCHRP Research Report 945: Strategies for Work Zone Transportation Management Plans provides a practitioner-ready guidebook on how to select and implement strategies that improve safety and traffic operations in roadway construction work zones. Supplemental materials to the report include NCHRP Web-Only Document 276: Evaluating Strategies for Work ZoneTransportation Management Plans; fact sheets on ramp meter, reversible lane, and truck restrictions; and guidebook appendices.

Best Practices for Work Zone Safety During Traffic Control Placement, Removal, and Modification - Phase I

Best Practices for Work Zone Safety During Traffic Control Placement, Removal, and Modification - Phase I PDF Author: John Anthony Gambatese
Publisher:
ISBN:
Category : Road work zones
Languages : en
Pages : 0

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Book Description
Studies have shown that drivers are at a higher risk of being involved in a crash when travelling through a work zone compared to normal driving conditions. Research further suggests that the crashes that occur in work zones are, on average, more severe than crashes that occur outside of work zones. The periods while temporary traffic control is being set-up, removed, or modified are also especially concerning given the exposure of the workers to traffic and the transition in the driving environment. This study aims to investigate the safety hazards and risk present during set-up, removal, and modification of temporary traffic control on high-speed roadways, and identify potential practices for improving safety during the traffic control deployment and removal processes. To date, the researchers have performed a comprehensive literature review on the study topic and conducted a survey of state department of transportation and highway construction contractor personnel. The results reveal a lack of a standard process/procedure and detailed guidance for setting up and removing traffic control. The survey results expose steps in the process that pose high risk to workers and motorists, such as when the traffic control is being placed to initially set the taper to close a lane. This document is an interim report that describes the study results to date and provides a proposed methodology for the remaining study tasks.

Speed Management

Speed Management PDF Author: European Conference of Ministers of Transport
Publisher: OECD Publishing
ISBN: 9282103781
Category :
Languages : en
Pages : 286

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Book Description
Speeding is the number one road safety problem in a large number of OECD/ECMT countries. It is responsible for around one third of the current, unacceptably high levels of road fatalities. Speeding has an impact not only on accidents but also on the ...

National Conference on Work Zone Safety

National Conference on Work Zone Safety PDF Author:
Publisher:
ISBN:
Category : Roads
Languages : en
Pages : 196

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Book Description
The National Conference on Work Zone Safety was designed to explore ways in which the highway construction industry and Federal, State and local governments can reduce accidents and fatalities in work zones. Attending the Conference were more than 200 people representing diverse safety areas, including educators, engineers, corporate and government officials. The two-and-a-half-day agenda was designed to offer a broad perspective from several disciplines as to the contributing factors causing accidents in work zones and possible remedies. During the Conference, participants separated into workshop groups that addressed the following topics: philosophy of traffic control; work zone safety implementation; contractors construction management; interaction with public highway users; and advanced technologies. This proceedings document summarizes the events of the Conference.

Integrated Work Zone Safety Management System and Analysis Tools

Integrated Work Zone Safety Management System and Analysis Tools PDF Author: Jian John Lu
Publisher:
ISBN:
Category : CD-ROMs
Languages : en
Pages : 181

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Book Description


Optimizing Work Zone Practices for Highway Construction Projects

Optimizing Work Zone Practices for Highway Construction Projects PDF Author: Tarek M. Elghamrawy
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Recent studies indicate that work zones suffer from an increasing trend of deaths and injuries in and around the highway construction areas with an average of 745 fatalities and 40,700 severe injuries per year. To control and minimize work zone fatalities and injuries, the Federal Highway Administration (FHWA), American Association of State Highway and Transportation Officials (AASHTO), and many state Departments of Transportation (DOTs) are seeking to improve the design practices of work zones to reduce work zone crashes. To support this vital and pressing highway safety goal, this research study focuses on analyzing and optimizing existing work zone practices and exploring the effectiveness and efficiency of innovative temporary rumble strips that can be used to minimize crashes in and around highway construction and maintenance projects. The research objectives of this study are to: (1) provide enhanced understanding of the impact of work zone parameters and innovative temporary traffic control devices on the safety of highway construction zones; (2) analyze work zone crashes and current practices to identify potential layout parameters that impact work zone crash occurrence; (3) investigate and quantify the impact of work zone layout parameters on the risk and cost of crash occurrence; (4) optimize work zone setup parameters to minimize total work zone costs including agency, user delay, and expected crash costs; (5) conduct field experiments to analyze the efficiency and constructability of various arrangements of temporary rumble strips prior to and at the edge of work zones; and (6) study and enhance the effectiveness of temporary rumble strips in alerting inattentive drivers prior to and at the edge of work zones. In order to achieve these objectives, the study is conducted in seven major tasks that focus on: (1) conducting a comprehensive literature review; (2) collecting and fusing all available data and reports on work zone crashes in Illinois; (3) analyzing work zone crashes and identifying the probable causes and contributing factors; (4) identifying the impact of layout parameters on risk of crash occurrence; (5) developing an optimization model to minimize total work zone costs including agency cost, user delay cost, and expected work zone crash cost; (6) performing field experiments on temporary rumble strips and evaluate the efficiency of utilization on site; and (7) evaluating the effectiveness of temporary rumble strips prior and at the edge of work zones. The main research developments of this study are expected to have significant impacts on (1) identifying potential work zone parameters and contributing causes that impact work zone crash occurrence; (2) estimating the probability of work zones to encounter severe crashes; (3) quantifying the impact of work zone parameters on the risk levels of crash occurrence; (4) estimating the monetary value of work zone crashes based on work zone layout parameters; (5) searching for and identifying optimal work zone setup solutions that specify segment length, operating speed, TTC policy, and concrete barrier at different operation staring times; (6) developing new efficient prototypes of temporary rumble strips to be utilized prior to and at the edge of work zones; and (7) developing practical guidelines for effective design arrangements of temporary rumble strips. These new developments hold a strong promise to: (a) improve work zone safety for both the travelling public and construction workers; (b) improve current work zone layouts, strategies, and standards; (c) provide a baseline for controlling the risk of crash occurrence due to highway work zones; (d) assist construction planners in identifying optimal work zone setups for highway construction; (e) direct the development of practical recommendations for efficient and effective design arrangements of temporary rumble strips; and (f) reduce work zone crashes in the work area through the implementation of practical temporary rumble strips arrangements.