The quality of progression of a road traffic stream is one of the critical characteristics that must be quantified for operational analysis of traffic signals, particularly on urban roads. The parameter that has been found to best describe this characteristic of traffic streams is the arrival type. Though precise quantification of arrival type has been found to be difficult, the platoon ratio is a useful measure for this purpose. Thus, the quality of arrival of a traffic stream can be assessed by knowing the corresponding value of the platoon ratio. Study of arrival type over a wide range of traffic characteristics warrants theoretical modeling of traffic flow. In the study reported, an attempt was made to model heterogeneous traffic flow using an innovative technique. The developed model was used to study the arrival type of traffic streams, queue accumulation, and queue dissipation on approaches to traffic signals. The dispersal pattern of traffic platoons after vehicles pass a traffic signal was studied in detail. The effect of variation in traffic composition on traffic platoons was also analyzed.