Ffects of Roadside Friction Elements on Travel Performance and Level of Service in Kigali

Abstract

Providing efficient mobility is the cornerstone of the socioeconomic development, however, the performance of the road transport systems in the developing countries' cities has been reduced and affected continuously due to the increase in road users both motorized and non-motorized and roadside friction elements. Recent researches revealed that efficiency in urban transport is affected by different factors associated with roadside activities. In most developing countries, cities, including Kigali City, a proliferation of roadside friction elements affect travel performance measures in the locations where these elements occur. This study attempts to analyze the effect of dynamic roadside friction factors on traffic performance measures such as speed and level of service using data collected from Kigali urban roads. Data collected included spot speed data, road condition data, traffic, and roadside elements data. All data were collected in the field over six road-stretches covering different functional classes of roads in Kigali City. Key roadside friction (RSF) elements that affect traffic performance were selected based on ANOVA results and a sensitivity analysis was carried out to quantify the impact of roadside friction factors on speed and level of service. Moreover, relationships of speed, density, and flow were developed taking into account typical dynamic roadside friction elements. Overall, it was found that roadside friction factors affect travel performance in the locations where they occur and their effects are not only on two-lane roads but also on four-lane roads. The models developed in this study take into consideration roadside friction factors, and therefore they can be used to predict operating mean vehicle speed and density. To minimize the effects of roadside friction factors on traffic performance, the research-based information and findings from this study can be used in setting out guidelines while imposing some restrictions to eradicate an occurrence and the proliferation of roadside friction elements.

Development of Mode-Wise Speed Prediction Models for Urban Roads with Side Friction Characteristics

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