A STUDY OF THE EFFECT OF ON-STREET PARKING ON TRAFFIC SPEED UNDER MIXED TRAFFIC CONDITIONS IN URBAN AREAS: A CASE STUDY IN ADDIS ABABA CITY

Abstract

On-street parking in city centers is an attractive facility for drivers. However, the availability of such parking facilities may affect the capacity of the highway and be a contributory cause reduction of traffic speed. On-street parking can impact the traffic speed and road capacity by the ways of the available lanes of road to accommodate on-street parking is the primary factor that reduces road capacity and traffic speed. The main objetives of these studies was to assess the impact of On-Street Parking on the traffic speed under mixed traffic conditions for Arada, Mercato, Kirkos and Ledeta location. To achieve the objective Traffic volume data, Speed studies data, and road width for each location mid-block and parking parameters was conducted for all this location at and away from parking during peak- hour period from 8:00 AM morning to 1:00 PM evening time for each 15 consecutive minutes. From those collected data was done to determine capacity of road at parking and away from parking then volume to capacity ratio at and away from parking to get level of service of the road. From, the collected data percentage of each vehicle also determined. From speed data collection at and away from parking percent of reduction speed also determined by using excel worksheet. The reduction rate is not the same for each 15 minutes consecutive interval for all vehicles. It varies with the category of the subject vehicle. It is observed that speed of vehicles like heavy vehicle or trucks reduces rapidly with the increase in traffic volume as compared to other categories of vehicles. The results showed that the vehicular speeds fell noticeably with an increase in parking levels. SPSS software used at analysis part and develop the model to get percentage of reduction speed. Analysis from the model clearly indicates that for a given road width at a location of on-street parking, as the parking turnover increases, or as parking duration increases, or as parking accumulation increases, or as traffic volume increases, the % of RS is also increases. Whereas, at a location of on-street parking keeping other parameter as a constant, as road width is increases, the percent of reduction speed was decreases and vice-versa. Keeping, the maximum reduction speed as 40% at selected location on-street parking for a road width of 8m, the traffic volume on the road should not exceed 1000 Pcu/hr and the parking turnover should be less than 0.6, parking duration should be less than 10minutes and parking accumulation should be less than 4