The effect of motorcycle proportion on traffic flow parameters at multi-lane urban road

The phenomenon of traffic flows in almost all major cities of Indonesia is large dominance in the use of motorcycles. The change in the proportion of motorcycle users on the streets reaches more than 50%. The author will discuss the effect of motorcycle volume proportion on traffic flow parameters such as speed and density. This research has been conducted at Ampang street with 4 lanes 2-way undivided type and Adinegoro street with 4 lanes 2-way divided type in Padang. By using Video Image Processor survey method, the data of traffic volume, and time travel of the vehicle for 12 hours were obtained. Further data is processed and the results are plotted into the graph by linear regression method. The results showed that the highest proportion of motorcycle volume of 75.9% occurred on Raya Ampang street and the lowest by 53.2% occurred on Adinegoro street (to the North). The result of linear regression analysis where proportion of motorcycle volume (p) as variable x and space-mean-speed (S) as variable y is S = -0.687(p) + 93.467, R2 = 0.8582 at Ampang street, S = -1.3273(p) + 143.75, R2 = 0.8153 at Adinegoro street (to the south), and y = -1.3861(p) + 131.94, R2 = 0.7882 at Adinegoro street (to the north). Then the relationship between space-mean-speed, density, and traffic volume analyzed