I. Introduction
This paper is an overview of the state of the art of traffic control and estimation both for classical techniques and for newer methods. The overviews start with a brief description of the most common models used for traffic control and estimation, looking towards models that include human and automated traffic. We will focus on the challenges that each model presents when dealing with traffic flow control and estimation problems. We then analyze how traffic flow is reconstructed using the most novel techniques as physics informed machine learning. The second part of the paper is focused on control techniques for freeway traffic flow, starting from the most classical ones, to end with the newest techniques that make use of connected and automated vehicles.