Development of a Methodology for Analyzing Safety Treatments at Isolated Signalized Intersections PDF Download

Author: Remigiusz M. Wojtal
Publisher:
ISBN: 9781267287700
Category : Roads
Languages : en
Pages :

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Author: Tae-Jun Ha
Publisher:
ISBN:
Category :
Languages : en
Pages : 404

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Author: Thanh Le (Highway engineer)
Publisher:
ISBN:
Category : Road markings
Languages : en
Pages : 92

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Book Description
Evaluates multiple low-cost safety improvements at signalized intersections for bacis signing, pavement marking, and signal enhancements.

Author: Young-Jun Kweon
Publisher:
ISBN:
Category : Roads
Languages : en
Pages : 86

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Book Description
This research was undertaken to develop an evaluation procedure to identify high-risk four-legged signalized intersections in VDOT's Northern Virginia district by traffic movements and times of day. By using the developed procedure, traffic engineers are expected to be able to identify signalized intersections where the traffic crash occurrences under different traffic conditions for different times of day are more frequent than would normally be expected. Using generalized linear models such as negative binomial models, one safety performance function was estimated for each of nine crash population reference groups formed by three traffic crash patterns (crash patterns 1, 4, and 6) and four times of day (A.M. peak, mid day, P.M. peak, and evening off peak). Crash pattern 1 is a same-direction crash (rear-end, sideswipe or angle crash) that occurs after exiting the intersection; crash pattern 4 is a right-angle crash between two adjacent straight-through vehicle movements in the intersection; and crash pattern 6 is an angle or head-on or opposite sideswipe crash between a straight-through vehicle movement and an opposing left-turn vehicle movement in the intersection. The procedure developed in this study is based on the empirical Bayes (EB) method. Additional data do not need to be collected in order to use the EB procedure because all the data required for applying the EB procedure should be obtainable from VDOT's crash database and from Synchro input data that are already available to traffic engineers for traffic signal phase plans. Thus, the EB procedure is cost-effective and readily applicable. For easy application of the EB procedure, an EB spreadsheet was developed using Microsoft Excel, and a users' guide was prepared. These are available from the author upon request.

Author:
Publisher:
ISBN:
Category : Electronic book
Languages : en
Pages :

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Author: National Research Council (U.S.). Highway Research Information Service
Publisher:
ISBN:
Category : Highway engineering
Languages : en
Pages : 930

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Author: Lee August Rodegerdts
Publisher: Transportation Research Board
ISBN: 0309155118
Category : Technology & Engineering
Languages : en
Pages : 407

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TRB's National Cooperative Highway Research Program (NCHRP) Report 672: Roundabouts: An Informational Guide - Second Edition explores the planning, design, construction, maintenance, and operation of roundabouts. The report also addresses issues that may be useful in helping to explain the trade-offs associated with roundabouts. This report updates the U.S. Federal Highway Administration's Roundabouts: An Informational Guide, based on experience gained in the United States since that guide was published in 2000.

Author: Xuesong Wang
Publisher:
ISBN:
Category : Generalized estimating equations
Languages : en
Pages : 195

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Book Description
Many methodologies and applications have been attempted in this dissertation. Therefore, the study has both theoretical and implementational contribution in safety analysis at signalized intersections.

Author: Sohail Zangenehpour
Publisher:
ISBN:
Category :
Languages : en
Pages :

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"Pedestrians and cyclists are amongst the most vulnerable road users as their accidents involving motor vehicles result in high injury and fatality rates for these two modes. Data collection for non-motorized road users remains a challenge and automated data collection methods are far more advanced for motorized traffic. To improve cyclist safety and promote urban cycling, cities have been building bicycle infrastructure, such as cycle tracks and bicycle boxes. These facilities have been built and expanded but due to the lack of appropriate data and problems with automated cyclist data collection, very little in-depth research has been carried out to investigate the safety impacts of these infrastructures. The majority of non-motorized safety studies are based on traditional methods which use observed accident and injury data. An important shortcoming of this approach is the need to wait for accidents to occur over several years. An alternative to traditional safety analysis is surrogate safety methods which can provide statistically sufficient data in a shorter time period. However, to perform surrogate safety studies, microscopic data from road users is needed. To address the shortcomings of the current literature and to improve the microscopic data collection tools for non-motorized road users, this thesis presents an automated methodology to classify road users in traffic videos - this methodology is complementary to existing object-tracking tools. The methodology is tested and validated using a large dataset from signalized intersections with high mixed traffic in Montreal, Canada. Road users are classified into three main categories: pedestrian, cyclist, and motor vehicle, with an overall accuracy of over 95 %. The proposed methodology is capable not only of counting the movements of the different road users (generating exposure measures), but also provides microscopic data separately for each road user type for safety analysis. As a result, performing automated surrogate safety studies becomes possible for facilities with mixed motorized and non-motorized traffic. As part of this thesis, the relationship between the surrogate safety measure used in this research, post encroachment time, and the historical accident data has been investigated and shows promising correlation. Using several hours of video recorded from a sample of signalized intersections in Montreal, and analyzed using the proposed techniques, the safety effects of two types of bicycle infrastructure, cycle tracks and bicycle boxes, have been investigated. The results show that based on the interactions between cyclists and turning vehicles, having a cycle track on the right side of the road is safer than not having a cycle track or than having a cycle track on the left side of the road. Also the study on the safety of bicycle boxes at intersections reveals that this type of bicycle facility is associated with a significant reduction in the severity of interactions (increase in post encroachment time) between cyclists and vehicles." --

Author: European Conference of Ministers of Transport
Publisher: OECD Publishing
ISBN: 9282103781
Category :
Languages : en
Pages : 286

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Book Description
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 ...