Abstract

This project has developed cost estimates and comparisons for the major urban transportation modes -- auto, bus, and rail -- using data from the San Francisco Bay Area. Intermodal cost comparison is useful for policy purposes, for it helps determine under what circumstances one mode is more efficient than another in terms of the resources it uses to provide a given service.

Abstract

Traffic accidents that occur on freeways often end tragically because of high driving speed. Wrong-way driving is also one of the causes of accidents on freeways. Research is based on the analysis of traffic accident data caused by wrong-way driving on freeways and considering valid technical specifications for connections and junctions design elements. Research is based on the analysis of the data of traffic accidents that occurred because of wrong-way driving on freeways and on the consideration of valid technical specifications concerning connections and junction design elements. The thesis presents possible countermeasures for prevention of wrong-way driving and consequential decrease in the number of traffic accidents. The proposed prevention countermeasures of wrong-way driving on freeways could greatly reduce incorrect traffic vehicle movements that are the consequence of wrong-way driving and thus positively enhance the traffic safety level on freeways. Prometne nesreče na avtocestah so zaradi velike hitrosti vožnje velikokrat tragične. Eden od vzrokov nastanka prometnih nesreč na avtocesti je tudi nepravilna smer vožnje. Raziskovalno delo je zasnovano na analizi podatkov o prometnih nesrečah zaradi nepravilne smeri vožnje na avtocestah, ter na osnovipoznavanja posameznih projektnih elementov vozlišč in priključkov. Predlagani ukrepi za preprečevanje nepravilne smeri vožnje na avtocestah lahko v veliki meri zmanjšajo število nepravilnih prometnih manevrov, ki imajo za posledico nepravilno smer vožnje in s tem pozitivno vplivajo na raven prometne varnosti na avtocestah.

Abstract

The fundamental diagram of a road, including free flow capacity and queue discharge rate, is very important for traffic engineering purposes. In the real word, most traffic measurements come from stationary loop detectors. This paper proposes a method to fit Wu’s fundamental diagram to loop detector data. Wu’s fundamental diagram is characterised by five parameters, being the free flow speed, wave speed, free flow capacity, queue discharge rate and jam density. The fits appear to be not very sensitive to the right value for the wave speed or the free flow speed. The proposed method therefore entails fixing these two parameters. The method consists of two steps. We first use a triangular fundamental diagram to separate the congested branch from the free flow branch. Then, the remaining three parameters of Wu’s fundamental diagram are fitted on each of the branches using a least square fit. This method is shown to be robust for cases tested in real life, and hence very noisy, data.