scholarly journals A parsimonious model for the safety assessment of horizontal curves using data from rural roads

2013 ◽  
Vol 3 (3) ◽  
pp. 184-195
Author(s):  
E. Matsoukis
Keyword(s):  
Safety Assessment ◽  
Rural Roads ◽  
Horizontal Curves ◽  
Parsimonious Model ◽  
Using Data

scholarly journals Speed Models for Motorcycle Riders for Two-lane Rural Roads

2021 ◽  
Vol 17 ◽  
pp. 595-603
Author(s):  
Panagiotis Lemonakis ◽  
George Botzoris ◽  
Athanasios Galanis ◽  
Nikolaos Eliou
Keyword(s):  
Prediction Models ◽  
Flow Speed ◽  
Operating Speed ◽  
Rural Roads ◽  
The Road ◽  
Horizontal Curves ◽  
Road Geometry ◽  
Speed Prediction ◽  
The Subject ◽  
On The Road

The development of operating speed models has been the subject of numerous research studies in the past. Most of them present models that aim to predict free-flow speed in conjunction with the road geometry at the curved road sections considering various geometric parameters e.g., radius, length, preceding tangent, deflection angle. The developed models seldomly take into account the operating speed profiles of motorcycle riders and hence no significant efforts have been put so far to associate the geometric characteristics of a road segment with the speed behavior of motorcycle riders. The dominance of 4-wheel vehicles on the road network led the researchers to focus explicitly on the development of speed prediction models for passenger cars, vans, pickups, and trucks. However, although the motorcycle fleet represents only a small proportion of the total traffic volume motorcycle riders are over-represented in traffic accidents especially those that occur on horizontal curves. Since operating speed has been thoroughly documented as the most significant precipitating factor of vehicular accidents, the study of motorcycle rider's speed behavior approaching horizontal curves is of paramount importance. The subject of the present paper is the development of speed prediction models for motorcycle riders traveling on two-lane rural roads. The model was the result of the execution of field measurements under naturalistic conditions with the use of an instrumented motorcycle conducted by experienced motorcycle riders under different lighting conditions. The implemented methodology to determine the most efficient model evaluates a series of road geometry parameters through a comprehensive literature review excluding those with an insignificant impact to the magnitude of the operating speeds in order to establish simple and handy models.

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

Safety Evaluation of Horizontal Alignment Design Consistency on Rural Two-Lane Highways

2019 ◽  
Vol 2673 (2) ◽  
pp. 628-636 ◽  
Author(s):  
Ian Hamilton ◽  
Scott Himes ◽  
R. J. Porter ◽  
Eric Donnell
Keyword(s):  
Negative Binomial ◽  
Safety Evaluation ◽  
Negative Binomial Regression ◽  
Expected Number ◽  
Horizontal Alignment ◽  
Highway Safety Manual ◽  
Horizontal Curves ◽  
Alternative Measures ◽  
Using Data ◽  
Design Consistency

Design consistency in the context of highway and street design refers to the conformance of highway geometry to driver expectancy. Existing design policies provide guidance related to horizontal alignment design consistency. While design consistency has safety implications and is intuitively linked to roadway departure crashes, the authors are only aware of a few studies that sought to link measures of design consistency to safety performance. This study explores relationships between alternative measures of horizontal alignment design consistency and the expected number of roadway departure crashes along horizontal curves on rural, two-lane, two-way roads. The authors analyzed 854 horizontal curves on rural two-lane highways in Indiana and Pennsylvania using data obtained from the SHRP 2 Roadway Information Database (RID) 2.0. Relationships between measures of design consistency and the expected number of roadway departure crashes were explored using a negative binomial regression modeling approach. The results indicate a relationship between the frequency of roadway departure crashes on a study curve and the radii of upstream and downstream curves. The ratio of the length of upstream and downstream tangents relative to a study curve radius was also statistically significant in Pennsylvania. Such findings are intuitive given the concept of design consistency and represent an advancement to existing predictive methods in the AASHTO Highway Safety Manual, which estimate the expected number of crashes on a segment as a function of the characteristics of only that segment.

Speeds of Cars on Horizontal Curves

1998 ◽  
Vol 1612 (1) ◽  
pp. 42-47 ◽  
Author(s):  
Vojo Andjus ◽  
Mihailo Maletin
Keyword(s):  
Free Flow ◽  
Flow Conditions ◽  
Passenger Cars ◽  
Design Standards ◽  
Rural Roads ◽  
Horizontal Curves ◽  
Road Design ◽  
Realistic Approach ◽  
Actual Design ◽  
Design Speed

Revision of existing Yugoslav road-design standards, specifically in the area of road-design speed definition, required studying driver behavior in free-flow conditions in order to define drivers’ responses to the radii of horizontal curves. A specific approach with variable design speed for horizontal curves is discussed and is supported by speed measurements on roads. The pilot research was undertaken on several test sites on Yugoslav two-lane rural roads to collect reliable speed data related to characteristics of horizontal curves. Characteristics of test sites, experimental procedures, data collected, and results of data analyses are described. It is concluded that speeds of free-flow passenger cars show good correlation with radii and that actual design policy with a constant design speed underestimates speeds in radii less than 250 m. Thus, the variable design speed concept is a more realistic approach. Further research on more test sites is recommended.

scholarly journals Taking a deeper look: Quantifying the differences in fish assemblages between shallow and mesophotic temperate rocky reefs

2018 ◽  
Author(s):  
Joel Williams ◽  
Alan Jordan ◽  
David Harasti ◽  
Peter Davies ◽  
Tim Ingleton
Keyword(s):  
Species Richness ◽  
Linear Models ◽  
Fish Assemblages ◽  
Habitat Type ◽  
Rocky Reefs ◽  
Temperate Reefs ◽  
Video Systems ◽  
Parsimonious Model ◽  
Using Data ◽  
Species Richness And Abundance

AbstractThe spatial distribution of a species assemblage is often determined by habitat and climate. In the marine environment, depth can become an important factor as degrading light leads to changes in the biological habitat structure. To date, much of the focus of ecological fish research has been based on reefs in less than 40 m with little research on the ecological role of mesophotic reefs. We deployed baited remote underwater stereo video systems (stereo-BRUVS) on temperate reefs in two depth categories: shallow (20-40m) and mesophotic (80-120m), off Port Stephens, Australia. Sites were selected using data collected by swath acoustic sounder to ensure stereo-BRUVS were deployed on reef. The sounder also provided rugosity, slope and relief data for each stereo-BRUVS deployment. Multivariate analysis indicates that there are significant differences in the fish assemblages between shallow and mesophotic reefs, primarily driven by Ophthalmolepis lineolatus and Notolabrus gymnogenis only occurring on shallow reefs and schooling species of fish that were unique to each depth category: Atypichthys strigatus on shallow reefs and Centroberyx affinis on mesophotic reefs. While shallow reefs had a greater species richness and abundance of fish when compared to mesophotic reefs, mesophotic reefs hosted the same species richness of fishery targeted species. Chrysophrys auratus (pink snapper) and Nemodactylus douglassii (grey morwong) are two highly targeted species in this region. While C. auratus was numerically more abundant on shallow reefs, mesophotic reefs provide habitat for larger fish. In comparison, N. douglassii were evenly distributed across all sites sampled. Generalized linear models revealed that depth and habitat type provided the most parsimonious model for predicting the distribution of C. auratus, while habitat type alone best predicted the distribution of N. douglassii. These results demonstrate the importance of mesophotic reefs to fishery targeted species and therefore have implications for informing the management of these fishery resources on shelf rocky reefs.

scholarly journals New approaches in drug safety assessment based on information provided by doctors and patients in the register “PROFILE”

The Clinician ◽  
2020 ◽  
Vol 13 (3-4) ◽  
pp. 29-35
Author(s):  
N. A. Dmitrieva ◽  
Yu. V. Lukina ◽  
N. P. Kutishenko ◽  
S. Yu. Martsevich
Keyword(s):  
Drug Therapy ◽  
Side Effects ◽  
Adverse Events ◽  
Drug Safety ◽  
Safety Assessment ◽  
Safety Information ◽  
Complete Information ◽  
Patient Relationship ◽  
Using Data ◽  
Different Sources

The aim to compare various sources of the pharmacotherapy safety information in the outpatient register.Materials and methods. The original questionnaire included several questions for assessing information about patients’ knowledge of the concept of AEs of drug therapy, awareness of the possibility of drugs’ AEs, how often patients read the instructions for drugs and actions of patients in cases of AEs occurrence. Adverse events appearance were noted by the patients themselves in questionnaire and by doctors when completing the IRCs for the period from September 1. 2017 to May 31. 2018 are compared.Results. Of the 162 patients who answered the questions in the original questionnaire, there were 80 women and 82 men. 112 patients were observed by doctors regularly (at least 1 time per year), 16 people visited doctors 1 time in 1–2 years, 14 people were with a doctor more than 2 years ago, in 18 patients information on the regularity of observation by doctors is not indicated were. According to the questionnaire, the majority of patients (145 (89.5 %)) were familiar with information about the possibility of developing side effects of drugs, and 125 (86.2 %) people received this information from their doctor, 19 (13.1 %) noted that the doctor did not inform them about this. Only 6 patients did not know anything about AE pharmacotherapy. As the questionnaire showed, most patients get acquainted with the instructions for the prescribed medications. Comparison of data from the IRCs and questionnaires revealed more frequent registration of AE by doctors; however, there was an incomplete coincidence of information about the presence of AE from different sources.Conclusion. Using data from the retrospective-prospective registry with obtaining information about adverse events from doctors in combination with simultaneous patients questionare could get more complete information about safety of pharmacotherapy. At the same time solution to the problem of farmacotherapy safety lives in optimizing the doctor–patient relationship.

The Effects of Edgeline Presence on Performance in a Driving Simulator under Sober and Alcohol-Dosed Conditions

1983 ◽  
Vol 27 (4) ◽  
pp. 329-329
Author(s):  
Thomas A. Ranney ◽  
Valerie J. Gawron
Keyword(s):  
Visual Information ◽  
Driving Simulator ◽  
Lateral Acceleration ◽  
Task Demand ◽  
Rural Roads ◽  
Pavement Markings ◽  
Horizontal Curves ◽  
Varying Length ◽  
Alcohol Effects ◽  
And Performance

Accident studies have identified nighttime conditions on rural roads as particular problems for alcohol-impaired drivers. Uneventful driving is hypothesized to result in progressive degradation of tracking performance and a reduced capability to handle the demands of hazardous locations, such as curves. To address these problems, simulations of continuous roadway treatments (i.e., wide edge lines) and spot treatments for curves (i.e., post delineators, chevron alignment signs, patterned pavement markings, and flashing displays) were evaluated experimentally. Twelve subjects drove a simulator under two conditions of task demand and three levels of BAC (0.0, 0.07, 0.12%). The objectives of the study were to determine the effects of alcohol and task demand on driving performance and to determine if providing enhanced visual information concerning roadway alignment would improve the performance of subjects when sober and/or alcohol-dosed. Alcohol effects were measured in terms of overall scenario performance, which included the number of accidents and speed exceedances, and performance on the approach and negotiation of horizontal curves of varying length and curvature. Curve approach and negotiation behavior were also used to evaluate the effects of the roadway treatments. Specific measures included spot measures of speed and lateral placement taken at eight 100-foot intervals along the curve approach and lateral acceleration and position taken continuously over the fixed portion of the curves. The results presented pertain to the effects of the presence of standard and wide edgelines. The discussion relates current findings to those from a previously conducted study.

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