DESIGN GUIDELINES FOR PASSING LANES ON RURAL TWO-LANE HIGHWAYS

Autor: CHEN, WENCHI, 陳文琦
Rok vydání: 1996
Druh dokumentu: 學位論文 ; thesis
Popis: 84
Two-lane highways constitute the predominant mileage of highway systems in Taiwan. Funds arelimited when compared with the extensiveness of two-lane highways system. Therefore, how toeffectively improve the two-lane highway with low-cost modifications becomes an important issue. Passing lanes are the most popular of these low-cost improvements. They can provide additionalpassing opportunities to improve the service level of two-lane highways effectively. This study tries to develop design guidelines for passing lanes in Taiwan. The guidelines areabout when to have a passing lane, its location, length and spacing. The factors considered in thisstudy include traffic flow, composition, direction split, grade and cruve radius. "Percent offollowing" is used as the criterion for evaluating the effect of a passing lane. "Percent offollowing " is defined as the perent of vehicles traveling at headways less than four seconds. The TRARR computer simulation model is used for evaluating the performance of passing lanes,because there are no passing lanes in Taiwan currently. A comprehensive validation test is conductedto examine the applicability of the TRARR simulation model in Tawan. The validation criteria includepercent of following, average spot speed, bunch size distribution, average travel time and averagetravel speed. The design guidelines developed in this study are based on deigned service level D which is with60 to 80 percent of following. TRARR simulation model is employed to develop a series of percent offollowing curves. These curves show that a 400 m passing lane is able to bring a reduction of percentof following from 80% to 60% for most siuations. The spacing of passing lanes is also discussed. Keys ： Design guidelines, Passing lane, Two-lane highway, TRARR, Percent of following.
Databáze: Networked Digital Library of Theses & Dissertations
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