Evaluation of the one-way traffic system along the Galle Road corridor

Traffic congestion is an extensive problem in urban environments in Sri Lanka. This is an in particular a serious problem in Colombo especially during peak periods. As a result of congestion, increase in following parameters; travel time, delays at intersections, accidents, fuel waste, and air pollution can be observed. To tackle the congestion problem several remedial actions have been used. As one such measure one way traffic flow system was introduced in 2006 between Bambalapitiya and Kollupitiya by City Traffic Police with the objective of reducing the traffic congestion. The objective of this research is to evaluate the performance of the one-way traffic arrangement along the Galle Road corridor. Quantitative research methodology was utilized in this study. The research data (traffic, accidents, new registered vehicles etc.) were gathered from several organizations and sources, which represent before and after the traffic system conversion. The traffic flow, travel time, number & severity of accidents, travelling speed, and emissions before and after the traffic conversion were analyzed in the specific stretch and compared. The results show that the traffic flow along the Galle Road has moderately reduced after the implementation of the one-way system but traffic flow on R.A. de Mel Mawatha has increased significantly. However, there is no significant difference in travel time along the both roads. The amount of emission along the Galle Road has reduced by about 50% of the earlier amount but along R.A. de Mel Mawatha it has increased. Travel distances have increased for many user groups especially the public transport users. Particularly bus commuters were faced lots of problem while they reach the bus halts and their destinations. Parking has been severely restricted on both road segments causing inconvenience to general public. After the implementation of one-way system the numbers of accident have been reduced but there is a clear indication of lack of enforcement. The above shows that the social cost of the present one-way system outweighs its expected benefits. Keywords: one-way traffic, accident, emission, travel time, public transport