Effect of Time and Foggy Conditions on Subjective Visibility

2005 ◽  
Vol 1911 (1) ◽  
pp. 85-104 ◽  
Author(s):  
Kazunori Munehiro ◽  
Roberto A. Tokunaga ◽  
Motoki Asano ◽  
Toru Hagiwara
Keyword(s):  
Traffic Control ◽  
Weather Condition ◽  
Warning Signs ◽  
Driving Safety ◽  
Pavement Markings ◽  
Test Road ◽  
Negative Effect ◽  
Dense Fog ◽  
Control Devices ◽  
Traffic Control Devices

In dense fog, the visibility of retroreflective traffic control devices is vital for driving safety. However, few studies have addressed the visibility of such devices in fog during a 24-h period (daytime, evening, and nighttime). This study measures the subjective visibility of the latest traffic control devices under various visibility conditions. An experiment was performed during a 2-month period in 2003 under natural fog at a test road 200 m long and 7.5 m wide in Eastern Hokkaido, Japan. Visibility conditions varied by daytime, evening, and nighttime and by weather condition factor (clear, cloudy, and dense fog). Thirteen kinds of traffic control devices were used as targets: two types of pavement markings, three of delineators, four of warning signs, and four of chevrons. Various newly developed materials were tested, and color and size were varied. The 20 women who participated in the experiment were required to make subjective judgments within a few seconds of the visibility of each target and their feeling of safety, assuming that they were driving on that section at 50 km/h. Results showed that daytime fog had a major negative effect on subjective visibility evaluations, while nighttime fog did not have as great a negative effect as that in daytime. However, the subjective visibility values of targets under the nighttime cloudy condition were worse than those under the daytime dense fog condition. Also, subjective visibility values for target objects made of highly reflective materials or incorporating fluorescent colors were high under both daytime fog and nighttime fog conditions.

Teenage Drivers’ Understanding of Traffic Control Devices

2000 ◽  
Vol 1708 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Garry L. Ford ◽  
Dale L. Picha
Keyword(s):  
Traffic Control ◽  
Warning Signs ◽  
Driver Education ◽  
Safe Driving ◽  
Left Turn ◽  
Pavement Markings ◽  
The Road ◽  
Control Devices ◽  
Traffic Control Devices ◽  
Teenage Drivers

Teenage drivers are involved in traffic crashes more often than any other driver group, and their fundamental knowledge of traffic control devices and rules of the road is extremely important in safe driving. Only limited data exist, however, on teenage drivers’ understanding of traffic control devices, and little research has been done on determining their comprehension thereof. Research was performed to document teenage drivers’ ability to understand 53 traffic control devices. These traffic control devices included 6 combinations of sign shape and color; 8 regulatory signs; 14 warning signs; 7 school, highway–railroad grade crossing, and construction warning signs; 7 pavement markings; and 11 traffic signals. Research results were then compared with previous comprehension studies to identify specific traffic control devices that the driving public continually misunderstands. In general, the results indicated that surveyed teenage drivers understood the traffic control devices to some degree. Only nine devices were understood by more than 80 percent of the respondents. The devices found problematic to teenage drivers include combinations of sign shape and color, warning-symbol signs, white pavement markings, flashing intersection beacons, and circular red/green arrow left-turn-signal displays. Recommendations include revising states’ drivers handbooks and increasing emphasis in the driver education curriculum to clarify the meaning and intent of problematic traffic control devices.

Pavement Marking Retroreflectivity Requirements for Older Drivers

1996 ◽  
Vol 1529 (1) ◽  
pp. 65-70 ◽  
Author(s):  
Johnny R. Graham ◽  
Joseph K. Harrold ◽  
L. Ellis King
Keyword(s):  
Field Study ◽  
Traffic Control ◽  
Older Drivers ◽  
Subjective Ratings ◽  
Pavement Markings ◽  
Subjective Evaluations ◽  
Significant Difference ◽  
Control Devices ◽  
Traffic Control Devices ◽  
Pavement Marking

Traffic pavement markings serve to regulate, guide, and channelize traffic and supplement other traffic-control devices. Because of their retroreflective properties pavement markings are critical for guidance at night, when reference objects near the edge of the roadway are difficult to see. Nighttime luminance levels provided by pavement markings that may be adequate for younger drivers may be less than adequate for older drivers. Both subjective evaluations and quantitative measures of in-place roadway markings were made to determine minimum marking retroreflectivity levels required for older drivers. In the field study more than 85 percent of subjects aged 60 years or older rated a marking retroreflectance of 100 mcd/m2/lx as adequate or more than adequate for night conditions. This base value does not include the effects of windshields and headlights that are less than clean or the variability of individual vehicle headlight performance. A comparison between the results for older drivers and the results of a similar 1989 study of younger drivers was also made. It was found that whereas the average subjective ratings were similarly distributed relative to the retroreflectivity of pavement markings, there was a significant difference in the subjective ratings made by older and younger drivers. Older drivers consistently rated the retroreflectivity of markings lower than did younger drivers.

Guidelines for Identification of Hazardous Highway Curves

2000 ◽  
Vol 1717 (1) ◽  
pp. 14-18 ◽  
Author(s):  
Bhagwant Persaud ◽  
Richard A. Retting ◽  
Craig Lyon
Keyword(s):  
Traffic Control ◽  
Empirical Bayes ◽  
Low Cost ◽  
Cost Effective ◽  
Warning Signs ◽  
Potential Treatment ◽  
Control Devices ◽  
Traffic Control Devices ◽  
The U.S

Curve-warning treatment can be extremely cost-effective because of the low cost of treatments, such as curve warning signs or markings, and the potentially large number of target crashes. However, measures are needed to identify and prioritize treatment of potentially hazardous rural curves. An empirical Bayes-based procedure is presented for prioritizing potential treatment sites on the basis of crashes that may be classified as occurring because of the presence of curves. The attractiveness of the procedure is enhanced by the fact that the data and calculations are also a part of the evaluation of treatment that may be applied to sites identified. Alternative levels of the procedure can be selected, depending on the data available. Ontario data were used to calibrate supporting models. It is hoped that experience gained from using the guidelines can lead to the development of procedures that can be incorporated into the U.S. Department of Transportation’s Manual on Uniform Traffic Control Devices.

Work Zone Traffic Accidents Involving Traffic Control Devices, Safety Features, and Construction Operations

1998 ◽  
Vol 1650 (1) ◽  
pp. 71-81 ◽  
Author(s):  
James E. Bryden ◽  
Laurel B. Andrew ◽  
Jan S. Fortuniewicz
Keyword(s):  
New York ◽  
Traffic Control ◽  
Construction Projects ◽  
Traffic Accidents ◽  
New York State ◽  
Work Zone ◽  
York State Department ◽  
Control Devices ◽  
Traffic Control Devices ◽  
Safety Features

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.

Modeling the Risk of Wrong-Way Driving Entry at the Exit Ramp Terminals of Full Diamond Interchanges

2018 ◽  
Vol 2672 (17) ◽  
pp. 35-47 ◽  
Author(s):  
Md Atiquzzaman ◽  
Huaguo Zhou
Keyword(s):  
Traffic Control ◽  
Initial Point ◽  
Geometric Design ◽  
Design Features ◽  
Entry Points ◽  
Control Devices ◽  
Traffic Control Devices ◽  
Diamond Interchanges ◽  
Transportation Agencies ◽  
Exit Ramp

Wrong-way driving (WWD) crashes are a critical safety issue on freeways. Although these crashes are rare and random in nature, they often result in severe injuries and/or fatalities. Typically, exit ramp terminals are the initial point of entry for wrong-way (WW) drivers on freeways. Therefore, it is important for transportation agencies to identify the exit ramp terminals with higher possibility of WW entries and apply safety countermeasures to reduce the chances of their occurrence. However, the random nature of WWD crashes and the difficulty in identifying the actual entry points makes it hard for transportation agencies to assess the risk of WWD at a particular exit ramp terminal and apply countermeasures accordingly. This study developed mathematical models for predicting the risk of WW entries at the exit ramp terminals of full diamond interchanges. The geometric design features, usage of traffic control devices, area type where the interchanges are located, and annual average daily traffic (AADT) at the exit ramp terminals with or without history of WWD were used as potential predictors of WW entry. Transportation agencies can use these models to assess the risk of WW entries at the exit ramp terminals within their jurisdictions and consider possible countermeasures. They also can be applied during the design phase to determine the combination of geometric design features and traffic control devices that ensures the least possibility of WW entry.

Functional tests of the ETCS and rail traffic control systems

2021 ◽  
Vol 133 ◽  
pp. 15-26
Author(s):  
Paweł Drózd ◽  
Adam Rosiński
Keyword(s):  
Traffic Control ◽  
Functional Model ◽  
Field Tests ◽  
Base Layer ◽  
Initial State ◽  
Railway Traffic ◽  
Control Devices ◽  
Traffic Control Devices ◽  
The Cost ◽  
The Impact

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.

Developing and Implementing Manual on Uniform Traffic Control Devices Criteria for Selecting Traffic Control for Unsignalized Intersections

2019 ◽  
Vol 2673 (11) ◽  
pp. 319-331
Author(s):  
H. Gene Hawkins ◽  
Kay Fitzpatrick ◽  
Marcus A. Brewer
Keyword(s):  
Traffic Control ◽  
Traffic Engineering ◽  
High Speed ◽  
Research Team ◽  
Right Of Way ◽  
Unsignalized Intersections ◽  
Control Devices ◽  
Traffic Control Devices ◽  
Urban Conditions ◽  
Selection Of

The 2009 United States Manual on Uniform Traffic Control Devices (MUTCD) includes guidance for the use of various types of traffic control at unsignalized intersections. Despite changes and advances in traffic engineering in recent decades, the MUTCD content related to selection of traffic control in Part 2B has seen only minor changes since 1971. The types of unsignalized traffic control addressed in the current research included no control, yield control, two-way stop control, and all-way stop control. The research team developed recommendations using information available from reviews of existing literature, policies, guidelines, and findings from an economic analysis along with the engineering judgment of the research team and panel. The researchers then developed recommended language for the next edition of the MUTCD for unsignalized intersections. This includes consideration of high-speed (rural) and low-speed (urban) conditions along with the number of legs at the intersection. Because the number of expected crashes at an intersection is a function of the number of legs, the decision on appropriate traffic control should also be sensitive to the number of legs present. The proposed language includes introductory general considerations, discusses alternatives to changing right-of-way control, and steps through the various forms of unsignalized control from least restrictive to most restrictive, beginning with no control and concluding with all-way stop control.

Effect of Pedestrian-Related Factors on Intersection Performance

2005 ◽  
Vol 1920 (1) ◽  
pp. 65-73
Author(s):  
Hoe Kyoung Kim ◽  
Michael P. Hunter
Keyword(s):  
Traffic Control ◽  
National Standard ◽  
Related Factors ◽  
Minimal Impact ◽  
Traffic Lane ◽  
Cycle Lengths ◽  
Control Devices ◽  
Traffic Control Devices ◽  
Walking Speeds ◽  
The Impact

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.

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