• Title/Summary/Keyword: Signalized intersections

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Evaluation of Left-Turn Passages for Bicycle Traffic in Mixed Traffic Stream at Signalized Intersections (혼합교통류 신호교차로에서 자전거교통 좌회전 통행방식 평가연구)

  • Joo, Shin-Hye;Oh, Cheol;Lee, Sang-Soo
    • International Journal of Highway Engineering
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    • v.14 no.5
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    • pp.145-155
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    • 2012

  • PURPOSES: This study proposes a novel method based on microscopic simulation models to evaluate bicycle passing ways in mixed traffic flow conditions at signalized intersections. METHODS: Both operational efficiency and safety are taken into consideration in the evaluation. A widely used performance measure, delay, is used for evaluating the operational efficiency. Regarding the safety evaluation, surrogate safety measures (SSM) to represent traffic conflicts and the level of crash severity, DeltaS and Max.DeltaV, are applied in the proposed method. RESULTS: Extensive simulations and statistical tests show that an integrated bike-box way is identified as the best in terms of operational efficiency and safety. CONCLUSIONS: The proposed method and outcomes of this study will be valuable for bicycle traffic operations and facility design.

  • https://doi.org/10.7855/IJHE.2012.14.5.145 인용 PDF KSCI

Impacts of Pre-signals on Traffic Crashes at 4-leg Signalized Intersections (전방신호기가 교통사고에 미치는 영향 연구)

  • Kim, Byeongeun;Lee, Youngihn
    • International Journal of Highway Engineering
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    • v.15 no.4
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    • pp.135-146
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    • 2013

  • PURPOSES : This study aimed to analyze the impact the operation of pre-signals at 4-leg signalized intersections and present primary environmental factors of roads that need to be considered in the installation of pre-signals. METHODS : Shift of proportions safety effectiveness evaluation method which assesses shifts in proportions of target collision types to determine safety effectiveness was applied to analyze traffic crash by types. Also, Empirical Bayes before/after safety effectiveness evaluation method was adapted to analyze the impact pre-signal installation. Negative binomial regression was conducted to determine SPF(safety performance function). RESULTS : Pre-signals are effective in reducing the number of head on, right angle and sideswipe collisions and both the total number of personal injury crashes and severe crashes. Also, it is deemed that each factor used as an independent variable for the SPF model has strong correlation with the total number of personal injury crashes and severe crashes, and impacts general traffic crashes as a whole. CONCLUSIONS: This study suggests the following should be considered in pre-signal installation on intersections. 1) U-turns allowed in the front and rear 2) A high number of roads that connect to the intersection 3) Many right-turn traffic flows 4) Crosswalks installed in the front and rear 5) Insufficient left-turn lanes compared to left-turn traffic flows or no left-turn-only lane.

  • https://doi.org/10.7855/IJHE.2013.15.4.135 인용 PDF KSCI

A Basic Investigation on the Characteristics of Traffic Flow for the Capacity Analysis of Signalized Intersections (교차로 용량분석을 위한 교통류 특성 기초조사)

  • 이승환
    • Journal of Korean Society of Transportation
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    • v.7 no.2
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    • pp.89-111
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    • 1989

  • This study concentrates on a basic investigation research related to some of parameters to be used for the analysis of capacity and the level of service for signalized intersections. The parameters to be studied are ideal saturation flow rate, large vehicle's passenger car equivalent(PCE) ane the lane utilization factors of through and left turn vehicles. The field data were collected at six intersections in Seoul using video cameras so as to reflect conditions in urban areas. In this study discharge headway based on a rear bumper of each vehicle was used and all the parameters were estimated using a regression technique. The findings of this research are as follows : 1. The saturation headway and saturation flow rate on a single lane with the lane width of 3.1m are 1.652 seconds and 2,180 pcphgpl. It was found that the frist 5 vehicles in the queue experience some start-up lost time. 2. It was confirmed that the new method adopted for the estimate of large vehicle's PCE gives larger PCE values than those derived from the method commonly used. 3. For the estimate of lane utilization factors of through and left turn vehicles, a relationship was established and the corresponding formulas were developed.

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