Resumen
Acceleration/deceleration (A/D) behaviour of vehicles is important for various applications like length of yellow light at inter- section, determination of sight distances at intersection, determination of length of A/D lanes, ramp design, traffic simulation modelling, vehicular emission modelling, instantaneous fuel consumption rate modelling, etc. Literature reports A/D studies for cars in lane disciplined homogeneous traffic. However, Indian traffic stream is weak lane disciplined and heterogenous, containing various vehicle types like truck, motorized three and two wheeler and diesel and petrol driven cars. Also, the reported studies are based on out of date data, collected using traditional and less accurate methods. Hence, this work aims to study the A/D behaviour of various vehicle types using modern instruments like Global Positioning System (GPS) in controlled manner including maximum A/D envelop. It is observed that acceleration rates of vehicles observed in this study, differed from acceleration rates reported in literature. On finding existing acceleration models insufficient to explain the acceleration behaviour of vehicles observed in this study, new models have been proposed and validated using statistical tools. Acceleration behaviour of cars varied with the change in gears, though the pattern remained similar in all gears.