Download or read book Controlling Speeds in Highway Work Zones written by Stephen H. Richards and published by . This book was released on 1984 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effectiveness of Changeable Message Signs in Controlling Vehicle Speeds in Work Zones written by Nicholas J. Garber and published by . This book was released on 1998 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: Highway work zones have been plagued with increasing numbers of accidents in recent years. Drivers' lack of compliance with speed restrictions within work zones has been cited as one of the major contributing factors to this trend. The conventional practice for regulating work zone speeds has been static signing procedures (using regulatory or advisory speed signs). It has been found that drivers do not slow down in response to these static control measures. Changeable message signs (CMS) equipped with a radar unit can be used to display specific warning messages to speeding drivers. The radar unit detects the speed of each vehicle entering the work zone and can be programmed to activate the CMS if the speed of the vehicle exceeds a preset threshold value. This offers a more dynamic speed control environment and therefore may prove to be more effective in influencing drivers to reduce their speeds. This report is the second phase of a longitudinal research study. The first phase of the project, conducted by Garber and Patel, examined the short term effectiveness of CMS in reducing vehicle speeds in work zones. That research established that the CMS (with the radar unit) is more effective in reducing speeds in work zones than the standard Manual on Uniform Traffic Control Devices (MUTCD) signs. This study, while attempting to replicate the results obtained in phase I of the project, concentrated on evaluating the effect of duration of exposure of the CMS with radar on its effectiveness in reducing speeds and influencing speed profiles in work zones. The impact of length of the work zone and vehicle type on speed reductions was also studied. Three work zone sites in southwest Virginia, two on Interstate 81 and one on a primary highway on Route 19, were selected for the study. Speed and volume data for the population were collected using automatic traffic counters at the beginning, middle and end of each work zone. In addition, the speeds of individual drivers who triggered the CMS by exceeding the threshold speed were also recorded (using a video camera) at two other locations within the work zone to study the behavior of high speed drivers in particular and to compute their average speed reduction in response to the warning message. The results of the study indicate that the duration of exposure of the CMS does not have a significant impact on speed characteristics and driver behavior. Therefore, the CMS continues to be effective in controlling speeds in work zones for projects of long duration. It was also determined that the drivers exceeding the speed limit, in both interstate work zones have on average reduced their speeds by around 12.86 km/h (8 mph) at the middle of the work zone. At the third site (Route 19) the speed reductions at the middle of the work zone were about 16.08 km/h (10 mph). It was also found that there were no distinctive differences among the different types of vehicles with regard to speed reduction. The study also established that in longer work zones, drivers who reduced their speeds in response to the speed control effort frequently have a tendency to speed back up as they approach the end of the work zone. This indicates that very long work zones might warrant the installation of a second CMS to maintain speed reductions through the work zone.
Download or read book Controlling Speeds in Highway Work Zones written by Stephen H. Richards and published by . This book was released on 1984 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Report written by and published by . This book was released on 1964 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Survey of Driver s Opinion about Work Zone Traffic Control on a Rural Highway written by R. F. Benekohal and published by . This book was released on 1990 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluation and Summary of Studies in Speed Control Methods in Work Zones written by R. F. Benekohal and published by . This book was released on 1992 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report summarizes and evaluates the important findings from the literature review of the studies on work zone speed control techniques. The following treatments are included in this report: 1) flagging, 2) lane width reduction, 3) law enforcement, 4) changeable message signs (CMS), 5) rumble strips, and 6) flashing beacons. The effects of the speed control treatments on speed and traffic flow are evaluated based on: A) experiences with treatment, B) effects of treatment on speed, C) effectiveness of treatment, and D) comments about treatment. A brief description of the conditions under which the treatments were applied is provided, and the speed reduction effects of each technique are discussed. A reference matrix was prepared to identify publications related to each type of speed reduction treatment used in work zones.
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 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 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 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 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 Speed Reduction Profiles of Vehicles in a Highway Construction Zone written by and published by . This book was released on 1992 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: In response to roadway geometry and traffic control devices, motorists may change their speeds within in a work zone. Speed profile data were collected for 208 vehicles who traveled a 1 .5-mile long section of a work zone, and speed reduction patterns were determined for Autos and Trucks. Four driver categories were identified based on the patterns. About 61% of the drivers reduced their speeds considerably after the first work zone speed limit signs, but nearly 15% of the drivers did not reduce their speeds until they neared the location of construction activities. About 11% of the drivers traveled at consistently high speeds and did not considerably reduce their speeds. The remaining drivers did not display a common pattern. The average speeds of Autos and Trucks were 5-18 mph and 1-12 mph, respectively, over the work zone speed limit. Vehicles decreased their speeds to the lowest level near the work space, but increased them after passing it. Even at the work space, about 65% of Autos and 47% of Trucks traveled faster than the speed limit. Autos and Trucks reduced their speeds by 3-13 mph and 3-12 mph, respectively, compared to their speeds at the beginning of the taper. The speeds at the beginning of the taper were used to group the vehicles into four speed groups. The maximum reduction in the average speed at different locations was greater with greater initial mean speeds; indicating that, on the average, the vehicles with higher initial speeds reduced their speeds more than the vehicles with lower initial speeds. However, the drivers in the higher initial speed groups kept higher speeds in the work zone than the drivers in the lower initial speed groups, even though the former group had greater speed reductions than the latter group.
Download or read book Synthesis of Practices for Work Zone Speed Management written by M. D. Harmelink and published by TAC = ATC. This book was released on 2005-01-01 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: Speeding in work zones is one of the most common traffic violations observed by road builders and road maintenance crews. It creates an unsafe environment for road workers and all types of road users. This synthesis is intended to help address this situation by reviewing work zone speed management efforts in Canada and the United States. The report provides an overview of technologies and methods for managing speed in work zones, with topics ranging from posted speed limit reductions and narrowing lanes to portable variable message signs and enforcement. In addition, the report discusses other methods for speed management, including merge control, driver and worker education, and real-time traffic information systems. The report also provides a number of conclusions and recommendations based on the synthesis, which identify some of the key problems and solutions.
Download or read book Flagging Handbook written by United States. Federal Highway Administration and published by . This book was released on 1980 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effectiveness of Changeable Message Signs in Controlling Vehicle Speeds in Work Zones written by Nicholas J. Garber and published by . This book was released on 1994 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: Work zone speeds have customarily been regulated by standard regulatory or advisory speed signs. However, most drivers do not slow down in response to these static speed control measures. The changeable message sign (CMS) with radar unit has dynamic capabilities which may be more effective in altering driver behavior. The radar, attached directly to the CMS, determines the actual speed of individual vehicles in the traffic stream. Upon detecting a speed higher than a preset threshold limit, the CMS can display a personalized warning message. This study evaluated the effectiveness of the CMS with radar unit in reducing work zone speeds. Four CMS messages designed to warn drivers that their speed exceeded the maximum safe speed were tested at seven work zones on two interstate highways in Virginia. Speed and volume data for the whole population traveling through the work zone were collected with automatic traffic counters. To assess the effect of CMS on high-speed drivers in particular, vehicles that triggered the radar-activated display were videotaped as they passed through the work zone. Using the data obtained from the traffic counters and videotapes, speed characteristics were determined at the beginning, middle, and end of the work zone. These characteristics were computed for the whole population and for high-speed vehicles separately. Statistical tests were then conducted using these speed characteristics to determine whether significant reductions in speed accompanied the use of CMS. Odds ratios were first calculated to compare the odds for speeding when using CMS with the odds for speeding when using the Manual on Uniform Traffic Control Devices (MUTCD) signing only. These odds ratios indicated that CMS effectively reduced the number of vehicles speeding by any amount, by 5 mph or more, and by 10 mph or more in the work zone. When analysis of variance was used to compare speeds when using the CMS with speeds when using MUTCD signing only, all of the speed characteristics average speeds, 85th percentile speeds, speed variance, and the percentage of vehicles speeding by any amount, by 5 mph or more, and by 10 mph or more were reduced with any of the four CMS messages. In some cases, these reductions were not significant at a= 0.05. The messages were rated according to their level of effectiveness in the following order: [1] YOU ARE SPEEDING SLOW DOWN, [2] HIGH SPEED SLOW DOWN, [3] REDUCE SPEED IN WORK ZONE, and [4] EXCESSIVE SPEED SLOW DOWN. Finally, t tests were conducted using the speed data obtained for the high-speed vehicles, and at a significance level of ct 0.05, all of the messages were effective in significantly reducing the average speeds of those vehicles traveling 59 mph or faster in a 55 mph work zone when compared to MUTCD signing only.
