Distance estimation is at the heart of automotive driver assistance systems (ADAS) and automated driving (AD). Simply stated, safe operation of vehicles requires robust distance estimation. Many different types of sensors (camera, radar, LiDAR, sonar) can be used for distance estimation, and different distance estimation techniques can be used with each type of sensor. Each type of sensor and technique has unique strengths and weaknesses. We’ll examine these techniques and their strengths and weaknesses, and show how multiple techniques using different sensor types can be fused to enable robust distance estimation for a specific automated driving application.