scholarly journals Driver Response to a Dynamic Speed Feedback Sign on Freeway Exit Ramps based on Sign Location, Interchange Type, and Time of Day

2020 ◽  
Author(s):  
Shakir Mahmud ◽  
Matthew Motz ◽  
Travis Holpuch ◽  
Anthony J. Ingle ◽  
Timothy Gates ◽  
...  
Keyword(s):  
Substantial Reduction ◽  
Light Condition ◽  
Field Evaluation ◽  
Time Of Day ◽  
Speed Reduction ◽  
Driver Response ◽  
Horizontal Curves ◽  
Before And After ◽  
Feedback Sign ◽  
Straight Segments

Roadway segments that include horizontal curves experience a disproportionate number of crashes compared to straight segments. Many of these crashes are lane departure-related, and excessive speed is often a contributing factor. One particularly vulnerable area for such crashes is freeway interchange ramps, which require a substantial reduction in speed to be safely negotiated. While dynamic speed feedback signs (DSFS) have been found to be an effective speed and crash reduction countermeasure at horizontal curves, the use of such signs on freeway interchange ramps has been limited nationwide. Consequently, the effectiveness of DSFS as a speed reduction countermeasure in such settings has remained largely untested. A before-and-after field evaluation was performed at three freeway exit ramps to assess the impacts of a DSFS on driver speed selection and braking characteristics while approaching and entering the ramp curves. The effectiveness of the feedback sign was tested across various conditions, including sign location, interchange type, time of day, light condition, and vehicle type. In general, the greatest benefits to driver behavior were achieved with the DSFS positioned at the point of curvature, during which curve entry speeds were reduced by approximately 2 mph compared to the pre-DSFS condition. These findings were consistent between the system- and service-interchanges and across all vehicle types. The DSFS was also found to be most effective during daytime off-peak periods compared to peak periods and at night. Based on the study findings, the continued use of DSFS as a speed reduction treatment at freeway exit ramps is recommended.

Evaluation of Alternative Messages and Sign Locations on Driver Response to a Dynamic Speed Feedback Sign on a Freeway Interchange Ramp

2020 ◽  
Vol 2674 (12) ◽  
pp. 530-541
Author(s):  
Timothy J. Gates ◽  
Md Shakir Mahmud ◽  
Anthony J. Ingle ◽  
Matthew Motz ◽  
Travis Holpuch ◽  
...  
Keyword(s):  
Driver Behavior ◽  
Field Evaluation ◽  
Speed Reduction ◽  
Driver Response ◽  
Heavy Trucks ◽  
Warning Message ◽  
Feedback Sign ◽  
Speed Management ◽  
Speed Selection ◽  
Advisory Speed

Research was undertaken to determine effective messaging strategies and sign positions for dynamic speed feedback signs (DSFS) when used for speed management at freeway ramp curves. A field evaluation was performed in this setting to assess the impacts of a DSFS on driver speed selection and braking characteristics while approaching and entering the curve. Three feedback messaging strategies were evaluated at three sign positions in advance of the curve. Compared with the existing site (without the DSFS), the DSFS reduced curve entry speeds and improved brake response across all test conditions, particularly for heavy trucks. Overall, considering the combination of both sign position and feedback messaging strategy, the greatest benefits to driver behavior were attained when the DSFS was positioned 255 ft upstream of the curve and the feedback message included the speed number alternating with a SLOW DOWN message. The inclusion of an advisory speed panel with the DSFS did not have a substantive impact on driver behavior. Based on the findings, the continued use of DSFS as a speed reduction treatment at freeway ramp curves is recommended. Specifically, the sign should be positioned to provide adequate time for drivers to perceive and react to the message, such that comfortable braking can be accommodated while approaching the curve. However, the sign should not be placed too far in advance of the curve, as drivers may be more likely to disregard such a premature warning message. Further evaluation of DSFS under various alternative ramp configurations is recommended.

scholarly journals Driver Response to a Dynamic Speed Feedback Sign on Freeway Exit Ramps Based on Sign Location, Interchange Type, and Time of Day

2021 ◽  
pp. 036119812110152
Author(s):  
Md Shakir Mahmud ◽  
Matthew Motz ◽  
Travis Holpuch ◽  
Jordan Hankin ◽  
Anthony J. Ingle ◽  
...  
Keyword(s):  
Time Of Day ◽  
Light Conditions ◽  
Driver Response ◽  
Beneficial Effects ◽  
Passenger Vehicles ◽  
System Versus ◽  
Feedback Sign ◽  
Speed Selection ◽  
Peak Versus ◽  
Horizontal Curvature

A series of field evaluations was performed at three freeway interchange ramps in Michigan that possessed significant horizontal curvature to assess the impacts of a dynamic speed feedback sign (DSFS) on driver speed selection and brake response while approaching and entering the ramp curve. A DSFS with a 15 in. full-matrix display was temporarily installed at each of the three exit ramp locations. The sign was programmed to display the same feedback message at each location, which included the speed number for all approaching vehicles, which alternated with a “Slow Down” message for vehicles approaching above 40 mph. The effectiveness of the feedback sign was tested across various sign locations (at the point of curvature versus 350 ft upstream), interchange types (system versus service), time of day (peak versus off-peak), light conditions (daylight versus darkness), and vehicle types (passenger vehicles versus trucks). Compared with the pre-DSFS site condition, the DSFS reduced curve entry speeds and improved brake response at two of the three ramp locations. In general, the greatest beneficial effects on driver behavior were achieved when the DSFS was positioned at the point of curvature, during which curve entry speeds were reduced by approximately 2 mph. These findings were consistent between the system interchanges and service interchanges, and across all vehicle types. The DSFS was also found to be most effective during daytime off-peak periods compared with peak periods and at night. Further evaluation of DSFS at additional ramp locations, and considering an expanded set of conditions, is recommended.

scholarly journals Evaluating Driver Response to a Dynamic Speed Feedback Sign at a Freeway Exit Ramp Considering the Sign Design Characteristics and Lateral Installation Position

2021 ◽  
Author(s):  
Shakir Mahmud ◽  
Babak Safaei
Keyword(s):  
Lateral Position ◽  
Sign Test ◽  
Detection Range ◽  
Speed Reduction ◽  
Driver Response ◽  
Feedback Sign ◽  
Improved Performance ◽  
Design Characteristics ◽  
Horizontal Curvature ◽  
Exit Ramp

Research was conducted at a freeway exit ramp with significant horizontal curvature to evaluate the effectiveness of dynamic speed feedback signs (DSFS) as a speed reduction countermeasure. Several aspects of the DSFS were evaluated, including display size, border type, lateral installation position, and vehicle detection range. Three different full-matrix DSFS were utilized, which included: 15-inch display panel with yellow border, 18-inch display panel with yellow border, and 18-inch display panel with no border. Each sign was individually installed and tested at identical locations near the start of the exit ramp curve, in both the traditional right-side-mount and an alternative forward-mount within the exit gore area. Speed data and message activation location were collected for vehicles approaching and entering into the curve across the various sign test conditions. Overall, the presence of a DSFS positioned near the start of the curve resulted in curve entry speeds that were, on average, 3.5 mph lower than without a DSFS present at the site. The lowest curve entry speeds were observed for cases where the message activated when vehicles were within 250 to 400 ft of the curve. Interestingly, earlier message activation did not contribute to further speed reductions, although later activation substantially diminished the speed reduction effects. Regarding DSFS lateral position, both the side-mounted and forward-mounted DSFS installations resulted in similar curve entry speeds. Furthermore, there were no discernable differences in curve entry speeds between the 15-inch and 18-inch display panels, although the inclusion of a yellow sign border improved performance.

CODE FAST: a quality improvement initiative to reduce door-to-needle times

2015 ◽  
Vol 8 (7) ◽  
pp. 661-664 ◽  
Author(s):  
Leslie Busby ◽  
Kumiko Owada ◽  
Samish Dhungana ◽  
Susan Zimmermann ◽  
Victoria Coppola ◽  
...  
Keyword(s):  
Quality Improvement ◽  
Univariate Analysis ◽  
Substantial Reduction ◽  
Heart Association ◽  
Time Of Day ◽  
Quality Improvement Project ◽  
Quality Improvement Initiative ◽  
Improvement Project ◽  
Process Improvements ◽  
Before And After

BackgroundRapid delivery of IV tissue plasminogen activator (tPA) in qualifying patients leads to better clinical outcomes. The American Heart Association has reduced target door-to-needle (DTN) times from 60 to 45 min in the hopes of continued process improvements across institutions.ObjectiveTo start a quality improvement project called CODE FAST in order to reduce DTN times at our institution.Materials and methodsWe retrospectively reviewed data from our internally maintained database of patients treated with intravenous tPA before and after implementation of the CODE FAST protocol. We assessed demographic information, time of day and times of arrival to first image and delivery of tPA in patients from February 2014 to February 2015. Outcomes were assessed based on discharge to home. Univariate analysis was performed to assess for improvement in DTN times before and after implementation of the protocol.ResultsA total of 93 patients (41 pre-CODE FAST and 52 post-CODE FAST) received IV tPA during the study period. Patients were equally matched between the two groups except that in the pre-CODE FAST era patients receiving tPA were younger and more likely to be men. There was a substantial reduction in door-to-imaging time from a median of 16 to 8 min (p<0.0001) and DTN time with a reduction in the median from 62 to 25 min (p<0.0001). In logistic regression modeling, there was a trend towards more discharges to home in patients treated during the CODE FAST era.ConclusionsWe present a quality improvement project that has been overwhelmingly successful in reducing DTN time to <30 min. The template we present may be helpful to other institutions looking to reduce their DTN times and may also reduce costs as we note a trend towards more discharges to home.

scholarly journals Pengembangan bahan ajar berbasis muatan lokal pada mata kuliah Pendidikan Kewarganegaraan

2016 ◽  
Vol 13 (2) ◽  
pp. 113-126
Author(s):  
Emil El Faisal ◽  
Sulkipani Sulkipani
Keyword(s):  
Student Achievement ◽  
Civic Education ◽  
Field Evaluation ◽  
Pilot Project ◽  
Local Content ◽  
Before And After ◽  
The Subject ◽  
The Mean ◽  
Potential Impact ◽  
History Department

This research aimed at (1) developing teaching materials based on local content for Civic Education in University; and (2) describing the potential impact of local content on student consciousness on local culture. It was a developmental research. The subject were student registered in Civic Education Course (Mata Kuliah PKn) at History Department. Pilot project was validated through one to one, small group, and field evaluation. The analyzed result indicates that the developed instrument was valid and has potential impact. Supported data shows that the mean score prior to implementation was 6.86 and after implementation was 7.73. In other words, there was an increasing student achievement before and after its implementation. Accordingly, we suggest that this developed material could be implemented widely.

Relationship between Predicted Speed Reduction on Horizontal Curves and Safety on Two-Lane Rural Roads in Spain

2014 ◽  
Vol 140 (3) ◽  
pp. 04013015 ◽  
Author(s):  
Juan de Oña ◽  
Laura Garach ◽  
Francisco Calvo ◽  
Teresa García-Muñoz
Keyword(s):  
Rural Roads ◽  
Speed Reduction ◽  
Horizontal Curves

Abstract 15666: Effectiveness of Sharpsense™ Algorithms in Reducing Pause and Bradycardia Detection: Real-world Performance Before and After the Software Upgrade in Confirm Rx™ Insertable Cardiac Monitor

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Rakesh Gopinathannair ◽  
Dhanunjaya Lakkireddy ◽  
Christopher Piorkowski ◽  
Muhammad Afzal ◽  
Ghulam Murtaza ◽  
...  
Keyword(s):  
Real World ◽  
False Positive ◽  
False Positive Rate ◽  
Substantial Reduction ◽  
Cryptogenic Stroke ◽  
Cardiac Monitor ◽  
Before And After ◽  
Positive Rate ◽  
Software Upgrade ◽  
Insertable Cardiac Monitor

Background: Recent enhancements have been introduced to the Abbott Confirm Rx™ insertable cardiac monitor (ICM) arrhythmia detection algorithms (SharpSense™). This study aims to characterize the real-world performance of SharpSense™ algorithms, in the upgraded ICM devices by comparing device detected pause and bradycardia (brady) episodes before and after the SharpSense™ upgrade. Methods: Confirm Rx™ devices with at least 90 days monitoring each before and after SharpSense™ upgrade were included in the study. Brady and pause episodes were extracted from Merlin.net™ patient care network for evaluation and adjudicated by expert adjudicators. Results: A total of 197 devices were included in the analysis. Devices were implanted for syncope (35%), AF management (33%), and other indications, including cryptogenic stroke and palpitations (32%). The SharpSense™ upgrade significantly reduced the total number of detected episodes by 92% (pause: 93%, brady: 87%) and the rate of transmitted episodes by 73.6% from 50.3 to 13.3 (pause: 34.9 to 6.0, brady: 7.8 to 1.5) episodes per patient-week (p < 0.001). SharpSense™ reduced false positive episodes by 82.8% and 91.5% for pause and brady, respectively. The percentage of devices with at least one false positive episode was reduced from 52% to 35% for pause and from 39% for 20% for brady. The number of devices with false positive rate greater than 1 episode per week was reduced from 39% to 20% for pause and from 23% to 8% for brady. Conclusion: SharpSense™ upgrade resulted in substantial reduction of pause and bradycardia episode detections, false positive detections, and frequency of transmitted episodes for clinic review.

scholarly journals Preparation and Characterization of Composites Materials with Rubber Matrix and with Polyvinyl Chloride Addition (PVC)

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1978
Author(s):  
Dan Dobrotă ◽  
Valentin Petrescu ◽  
Cristinel Sabin Dimulescu ◽  
Mihaela Oleksik
Keyword(s):  
Substantial Reduction ◽  
Accelerated Aging ◽  
Mechanical Tests ◽  
Point Of View ◽  
Rubber Matrix ◽  
The Finite Element Method ◽  
Composites Materials ◽  
Before And After ◽  
Conveyor Belts

An important problem that arises at present refers to the increase in performances in the exploitation of the conveyor belts. Additionally, it is pursued to use some materials, which can be obtained by recycling rubber and PVC waste, in their structure. Thus, the research aimed at creating conveyor belts using materials obtained from the recycling of rubber and PVC waste. Under these conditions, conveyor belts were made that had in their structure two types of rubber and PVC, which was obtained by adding in certain proportions of reclaimed rubber and powder obtained from grinding rubber waste. In order to study the effect of adding PVC on properties, four types of conveyor belts were made, with the structure of rubber, PVC and textile reinforcement. These have been subjected to certain mechanical tests, also being analyzed from the point of view of the behavior of the accelerated aging. The results obtained showed that the addition of PVC lead to a decrease in tensile stress for the strips made, but also an increase in the tensile strain. Additionally, the elasticity tests performed before and after the accelerated aging showed that the presence of PVC in the structure of the conveyor belts determined a substantial reduction of the aging process of the rubber in the conveyor belts. Under these conditions, it has been established that the use of PVC in the structure of rubber matrix conveyor belts is beneficial if conveyor belts are to be produced that are less subject to mechanical stress, but that work in conditions that can cause accelerated aging of materials. An analysis with the finite element method (FEM) of the test samples was also performed.

scholarly journals Identification of Determinants of the Speed-Reducing Effect of Pedestrian Refuges in Villages Located on a Chosen Regional Road

Symmetry ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 597
Author(s):  
Alicja Sołowczuk ◽  
Dominik Kacprzak
Keyword(s):  
Traffic Engineering ◽  
Geometric Parameters ◽  
Speed Reduction ◽  
The Road ◽  
Traffic Calming ◽  
Engineering Discipline ◽  
Number Of Factors ◽  
Before And After ◽  
Layout Geometry ◽  
Specific Factors

Traffic calming, as a traffic engineering discipline, is becoming an increasingly important aspect of the road engineering process. One of the traffic calming treatments are pedestrian refuges—raised islands located on or at the road centreline. This paper presents factors relevant to the performance of this kind of traffic calming devices retrofitted on the stretches of regional roads in village areas. To this end, speed surveys were carried out before and after the islands in each direction on purposefully chosen test sections. In order to identify the determinants, each test section was characterised by features including the symmetry of the road layout geometry, surrounding features and the existing traffic signs and, last but not least, visibility of the road ahead. The survey data were used by the authors to perform analyses in order to group the speeds at the pedestrian refuges and relate them to specific factors and, finally, identify the determinants of speed reduction. In this way, the authors arrived at a conclusion that the performance of pedestrian refuges depends on a number of factors rather than solely on their geometric parameters. The analyses showed that the pedestrian refuge geometric parameters, features located in its proximity that influence the driver’s perception and placement of appropriate marking, can, in combination, result in achieving the desired speed reduction and ensure safety of non-motorised users. These hypotheses were tested on a stretch of a regional road in village area at three points of the process: before upgrading, after installation of pedestrian refuges, and after retrofitting of enhancements.

RESTORATION BY OESTRADIOL BENZOATE OF A NEURAL AND HORMONAL RHYTHM IN THE OVARIECTOMIZED RAT

1975 ◽  
Vol 64 (1) ◽  
pp. 27-35 ◽  
Author(s):  
F. R. BURNET ◽  
P. C. B. MACKINNON
Keyword(s):  
Single Injection ◽  
Time Of Day ◽  
Ovariectomized Rats ◽  
Female Rat ◽  
Functional Link ◽  
Initial Injection ◽  
Oestradiol Benzoate ◽  
Before And After ◽  
Lh Release ◽  
The Brain

SUMMARY The rate of [35S]methionine incorporation into protein in discrete cerebral areas was measured before and after the administration of oestradiol benzoate (OB) to chronically ovariectomized rats. The circadian rhythm of incorporation which is normally seen in the intact cyclic female rat was deleted by ovariectomy. A daily rhythm of incorporation reappeared, however, in all the brain areas studied 30 h after a single injection of OB (20 μg), and was still present 12 days later. The release of luteinizing hormone (LH) after administration of 20 μg OB was measured in chronically ovariectomized animals and was found to be biphasic. High levels of LH after ovariectomy were initially reduced by negative feedback, but this phase was followed 52 h later by a facilitation of LH release between 15.00 and 18.00 h. The facilitation of LH release at this time of day was still detectable 12 days after the initial injection. The evidence for a functional link between the rhythm of neural activity which is reflected by [35S]methionine incorporation, and the ability to 'time' the facilitation of LH release is discussed.

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