Simulating any nontrivial traffic situation requires describing not only acceleration and braking but also lane changes. When modeling traffic flow on entire road networks, additional discrete-choice situations arise such as deciding if it is safe to enter or cross a priority road, if cruising or stopping is the appropriate driver’s reaction when approaching a traffic light which is about to change to red, or when planning to overtake a slower vehicle on the lane for opposite traffic. This chapter presents a unified utility-based modeling framework for such decisions including tactical aspects such as trajectory planning and numerical implementation.