The present study is undertaken to fulfill the following objectives: (i) To collect data for calculating the time progress of different vehicles on six-lane urban roads under mixed traffic conditions. (ii) I use real field data collected from traffic monitoring sites on six-lane urban roads to determine free-flow speed (FFS). (iii) Establish a relationship between headway and free-flow speed for six-lane urban roads under mixed traffic conditions. Traffic conditions on Indian roads are heterogeneous in nature. It consists of fast vehicles such as cars, other motor vehicles and slow vehicles such as bicycles. These vehicles differ widely in physical structure, size, driving force, control and guidance system, as well as performance capabilities. The difference in static and dynamic characteristics of different values ​​affects the traffic flow. The characteristics of Indian traffic are fundamentally different from those of developed countries, due to the mixed traffic flow. This complex traffic scenario, especially prevalent on urban roads in developing countries, represents a serious challenge for traffic planners and engineers who are looking for suitable solutions. Solutions to the traffic problem can be found through the systematic study of all relevant characteristics of mixed traffic, using appropriate models that will replicate the traffic flow in the field. The main hypothesis behind the project is to evaluate the relationship between headway and free-flow speed based on actual data under mixed traffic flow conditions. On most urban roads in India, traffic consists of an unsegregated flow of different types of vehicles. Traffic in most developing countries like India is heterogeneous and includes vehicles located in central city areas. Arterial roads essentially serve more time during travel; it also provides access to adjacent commercial and residential land uses. Collector roads provide both access to the territory and the circulation of traffic within commercial, residential and industrial areas. Urban roads are classified between local roads and multi-lane suburban and rural highways in road transport structures. Downtown streets are signposted structures that often function as thoroughfares during peak traffic hours. The difference is fundamentally determined by road function, control conditions, character and intensity of road development. Multi-lane suburban and rural highways differ from urban streets in the following ways: road development is not as intense, the density of traffic access points is not as high, and signalized intersections are more than 3.0 km apart per day. from each other.