Download or read book Evaluation of Work Zone Speed Reduction Measures written by T. H. Maze and published by . This book was released on 2000 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Iowa Department of Transportation (DOT) has made improving work zone (WZ) safety a high priority. Managing vehicle speeds through work zones is perceived to be an important factor in achieving this goal. A number of speed reduction techniques are currently used by transportation agencies throughout the country to control speeds and reduce speed variation at work zones. The purpose of this project is to study these and other applicable work zone speed reduction strategies. Furthermore, this research explores transportation agencies' policies regarding managing speeds in long-term, short-term, and moving work zones. This report consists of three chapters. The first chapter, a literature review, examines the current speed reduction practices at work zones and provides a review of the relevant literature. The speed control strategies reviewed in this chapter range from posting regulatory and advisory speed limit signs to using the latest radar technologies to reduce speeds at work zones. The second chapter includes a short write-up for each identified speed control technique. The write-up includes a description, the results of any field tests, the benefits and the costs of the technology or technique. To learn more about other state policies regarding work zone speed reduction and management, the Center for Transportation Research and Education conducted a survey. The survey consists of six multipart questions. The third chapter provides summaries of the response to each question.

Download or read book Work Zone Speed Management written by John W. Shaw and published by . This book was released on 2015 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Evaluation of Work Zone Speed Limit Signs with Strobe Lights written by R. F. Benekohal and published by . This book was released on 1992 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: The construction zone speed limit sign used in Illinois consists of a regulatory 45 mph speed limit sign augmented with two small strobe lights and two orange colored plates. When the lights are flashing the speed limit is 45 mph. This report contains the findings from evaluation of the effectiveness of the flashing lights in reducing speeds in a rural interstate construction zone. The speed reduction effects on cars and trucks were determined at two locations within the work zone. The results indicated that the average speed of cars was reduced by 1.9-7.1 mph and that of trucks by 1.3-6.0 mph when the strobe lights were flashing. In general, the speed reduction effects were more pronounced on the cars than on the trucks, and at a location past the work space than before it. The reductions at the location past the work space were 2-3 times more than the reductions at the location before the work space. Cars reduced their speeds, on the average, by 1.9 to 4.9 mph before and by 5.9 to 7.1 mph after the work space. Similarly, the speed reduction for trucks was 1.3-2.9 mph before and 3.3-6.0 after the work space. In general, the percentages of vehicles with excessive speeds in the work zone decreased when the lights were flashing.

Download or read book Speed Reduction Methods and Studies in Work Zones written by R. F. Benekohal and published by . This book was released on 1992 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objectives of this project were to determine the effectiveness of speed control methods and study traffic behavior in construction zones. This report provides a brief introduction and summary of findings from the following reports which were prepared as part of this study: (1) Evaluation and Summary of Studies in Speed Control Methods in Work Zones. (2) Evaluation of a Radar-Activated Horn System for Speed Control in Highway Maintenance Operations. (3) Survey of Driver's Opinion about Work Zone Traffic Control on a Rural Highway. (4) Speed Reduction Effects of Drone Radar in Rural Interstate Work Zones. (5) Speed Reduction Effects of Changeable Message Signs in a Construction Zone. (6) Effects of Police Presence on Speed in a Highway Work Zone: Circulating Marked Police Car Experiment. (7) Evaluation of Work Zone Speed Limit Signs with Strobe Lights. (8) Speed Reduction Profiles of Vehicles in a Highway Construction zone. Data only for those vehicles in free flow traffic are used for speed reduction evaluation. A vehicle was considered to be in free flow traffic when its time headway was greater than 5 seconds.

Download or read book Evaluation of Traffic Controls for Highway Work Zones written by Richard F. Pain and published by . This book was released on 1979 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Better Management of Speed Control in Work Zones written by and published by . This book was released on 2006 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: Statistics from the South Carolina Department of Transportation (SCDOT) for incidents between 1998 and 2002 reveal that a leading cause of crashes in work zones is driving too fast for conditions. In April 2005, a team of researchers led by Clemson University Transportation Systems Laboratory embarked on research to better manage speed control in work zones. The research tasks included field trials of several devices, a literature review, and a survey of states. Based on the literature review and meetings with the project steering committee, a number of devices and strategies were selected for field evaluation. The selected devices included drone radar, changeable message sign with radar (CMR), a speed monitoring display (SMD) with CMS, portable rumble strips, and a novel speed activated sign designed by the researchers. Each of the devices had to be acquired and/or developed for this project and preliminary testing was conducted to identify an acceptable configuration for actual data collection. After the initial testing, field surveillance of the speed management devices at a variety of different work zone sites on interstates and state route highways in South Carolina was completed to collect the empirical data needed for evaluation. Both quantitative and qualitative analyses of the performance of the devices and strategies were completed. Some of the devices were also studied in combination with police enforcement. The results of the analysis show that all of the speed control devices studied during this project has the capability of lowering speeds. This report summarizes the findings of this research and provides several recommendations in choosing a speed control device for a particular work zone application.

Download or read book Strategies for Work Zone Transportation Management Plans written by Leverson Boodlal and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Evaluation of Variable Speed Limits in Work Zones written by Disapat Lavansiri and published by . This book was released on 2003 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Improving Work Zone Safety Through Speed Management written by Norman M. Sommers and published by . This book was released on 2013 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Speed Control Through Work Zones written by and published by . This book was released on 1987 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Identification and Testing of Measures to Improve Work Zone Speed Limit Compliance written by Marcus A. Brewer and published by . This book was released on 2005 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Speed Reduction Effects of Changeable Message Signs in a Construction Zone written by R. F. Benekohal and published by . This book was released on 1992 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study evaluated the vehicular speed reduction effects of displaying speed limit and information messages on a changeable message sign (CMS) placed inside the work activity area in a work zone for a one lane closure on a rural interstate highway. It also examined the additional effects of using two CMS devices compared to one CMS. The following three experiments were conducted: (1) One CMS in advance of the work zone (Experiment 1), (2) One CMS inside the work activity area (Experiment 2), and (3) Two CMSs inside the work activity area (Experiment 3). Displaying speed limit and information messages on CMSs placed in the work activity area was effective in reducing the average speed and percentages of vehicles with excessive speeds. Comparing the results from Experiments 2 and 3 indicated that displaying the CMS messages reduced the speed of cars immediately after passing the CMS, but not at a point far from the CMS. Although trucks did not consistently reduce their speeds near the first CMS, trucks traveled at reduced speeds after passing the CMS. Cars and trucks reduced their speeds by as much as 5 and 4 mph, respectively, near the CMS. The speed reduction depended on the travel speed of the vehicles. Placing the CMS in the work activity area was more effective than putting it in advance of the work zone.

Download or read book Speed Management written by European Conference of Ministers of Transport and published by OECD Publishing. This book was released on 2006-10-13 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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 ...

Download or read book Effects of Police Presence on Speed in a Highway Work Zone written by R. F. Benekohal and published by . This book was released on 1992 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study evaluated the effects of police presence on the speed of vehicles in a work zone and determined the "halo" effects of police presence (lasting effects when police are gone) on vehicular speeds. A marked police car circulated in a 4-mile long interstate highway work zone and actively enforced the speed limit laws. Variables such as the average speed, speed distribution, percentage of fast-moving motorists, and net speed reductions for cars and trucks were used for evaluation. The results indicated that the average speeds of the cars and trucks were 4.3-4.4, and 4.3-5.0 mph, respectively, lower when police were patrolling the work zone compared to no-police patrol condition. The percentage of fast-moving cars and trucks before the work space decreased by 14% and 32%, respectively, when police were in the work zone. These speed reductions indicate that the police presence was effective in decreasing the speed of vehicles in the work zone. The police presence had halo effects on trucks but not on cars. Trucks traveled at reduced speed when police were present in the work zone and this trend of traveling at the reduced speed continued for a time period at least one hour after the police departed from the work zone. However, cars traveled 2. 4-3. o mph faster and the percentage of fast-moving cars in the work zone increased after the police left the area.

Download or read book Mobility and Safety Evaluation of Integrated Dynamic Merge and Speed Control Strategies in Work Zones written by Syed Muhammad Zaier Abbas Zaidi and published by . This book was released on 2010 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book An Evaluation of Speed Control Techniques in Work Zones work Zones 2 written by R. W. Lyles and published by . This book was released on 1999 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Guidance for Implementation of the AASHTO Strategic Highway Safety Plan written by Nicholas D. Antonucci and published by Transportation Research Board. This book was released on 2005 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt: