Browsing by Author "Mershaye, Wuletaw"

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    Assessing Effect of Speed Hump on Traffic Flow in Addis Ababa at Selected Segments
    (Addis Ababa University, 2022-06) Mershaye, Wuletaw; Bikila, Teklu (PhD)
    In Addis Ababa the speed calming devices are installed on all road hierarchies with a posted speed limit of 30km/hr for LS, CS&SAS and RR 50km/hr. respectively. Due to the lack of clear and uniform design standards and guidelines for the installation of speed humps in Addis Ababa led to their existence on streets with heavy traffic volumes, which caused considerable traffic delay at the locations of speed humps. The speed hump geometry (Length & width), grade of road along speed hump, speed of vehicles, delay and counted vehicle are used for analysis to generate a regression model. The research has been worked with qualitative(questionary) and Quantitative (direct study) which try to associate the two approaches. In this thesis work, the hump geometry characteristics, geometry of the road, speed of each individual travelling vehicles and delay of vehicles are the main parameters that studied. As per the analysis model the geometry of speed hump has variable effects on vehicle movement at upstream approaching distance of the vehicles. Up to 25-meter upstream distance is used which a car locates at the spot speed of cars approaching the humps with free flow speed taken as first point that 25m before speed hump and can catch up to enough vehicle. The overall result shows that the average maximum speed reduction of 16.66km/hr,15.2km/hr,13.8 km/hr,11.31km/hr. &9.67 km/hr. for (Car), (Bajaj, cycle & motor cycle), (Pick up, Mini bus Taxi), (Medium Bus Truck) and (Large Bus & TT) respectively. From the delay analysis, the car group has maximum delay value (164.5 Veh. /min) than other vehicle groups. In the model, the speed hump height, length and grade of the road has direct relation with the delay at upstream of the speed hump.