Traffic engineering works on the network a city already has: its junctions, streets, centre and the movement of goods. Rahyaft designs and improves the geometry of junctions and interchanges, reorganises urban traffic and freight movement, prepares traffic management plans for city centres, and carries out traffic impact studies for large developments that attract and generate trips. It also assesses intelligent transport systems (ITS), and all of it rests on data and simulation.
Part of the work is annual area studies for municipalities; part is commissioned by developers of large projects. Examples include the traffic studies of Tehran Municipality Region No. 17 for the Tehran Transportation and Traffic Organization, the ITS development studies for Qom Municipality, and the traffic impact study of the National Iranian Gas Company's central offices.