Evaluation of traffic operating conditions on two urban arterials in metropolitan Dhaka

Abstract

The traffic operating conditions on two urban arterials- Kazi Nazrul Islam Avenue and Mirpur Road were assessed in this research work. The operating condition was measured in terms of the familiar level of service (LOS) criteria as suggested in the Highway Capacity Manual. •."- .. A total length of 4:S-kriJ on Kazi Nazrul Islam Avenue and 3.4 km on Mirpur Road were studied. The study'inctuded collection of field data on traffic volume, composition, and travel time. The KaziNazrul Islam Avenue was divided into six different study sections while the Mirpur Road was divided into eight different study sections. Traffic volumes on these roadways were found to be as high as 7500 vph to as low as just over 2500 vph. On the roadway sections of Kazi Nazrul Islam Avenue, the predominant type of vehicles was light vehicles and three wheelers while on Mirpur Road the non-motorized vehicle in the form of mainly rickshaws, and bicycles and pushcart to a lesser extent dominates. They consisted of around 50 to 60% of the total traffic volume. Among the motorized traffic on Mirpur Road, the predominant types are light vehicles and three wheelers. The average speeds of three predominant types of motorized vehicles bus, light vehicle, and threewheeler on Kazi Nazrul Islam Avenue were found to be lied between 20 - 33 kmph , 20- 35 kmph, and 19 to 30 kmph, respectively. On the other hand, speeds of motorized vehicles on Mirpur Road were found to be lied between 19 - 25 kmph, 20 - 31 kmph, and IS - 27 kmph for bus, light vehicle and three-wheeler, respectively. Traffic data collected at study sites also showed that the delays experienced by the motorized vehicles on Mirpur Road were much higher than on Kazi Nazrul Islam Avenue. Average delays caused to the motorized vehicles on Kazi Nazrul Islam Avenue were found to be less than 50 seconds per vehicle per kilometre of travel, while the average delays experienced by the motorized vehicles on Mirpur Road were found to be lied between approximately 65 to 90 seconds per vehicle per kilometre of travel. Besides other factors, this may be attributed to the presence of large number of slow moving nonmotorized vehicles on Mirpur Road. The results showed that most of the study sections of Kazi Nazrul Islam Avenue were operating at a level of service of C. Similarly, most of the sections of Mirpur Road were operating at a level of service of D_ The speed and delay models were also formulated using the data collected at study sites. The results of the analyses showed that the models were significant at 5% level of significance (i.e., 95% confidence level). Moreover, the relationships between the dependent and independent variables were found to be logical. It is to be noted here that the LOS estimated for different study sections of these two roadways indicates the operating conditions at the time of collection of traffic data. However, LOS for any other times, which very likely to have different amount traffic volume, can be estimated using the speed models developed in this study. The models developed in this study can also play roles in traffic management on these two primary roads of Metropolitan Dhaka. Because the models indicate that reduction of traffic volume as well as reduction of non-motorized vehicles can increase the speed of the motorized vehicles and consequently reduce the delays. It was recommended that high occupancy motorized vehicles like buses can be an effective alternative in this regard.