High performance automotive radar systems are currently under development for various applications. Comfort systems like adaptive cruise control (ACC) are already available on the market as 77 GHz radars. Target range and velocity are measured simultaneously with high resolution and accuracy even in multi-target situations. Future developments will be more concentrated on safety applications like collision avoidance (CA) or autonomous driving (AD). In this case, the requirements for reliability (extreme low false alarm rate) and reaction time (extreme short delay) are much higher compared with ACC systems. To meet all these system requirements, specific waveform design techniques must be considered. For ACC systems, both radar types of classical pulse waveform with ultra short pulse length (10 ns) or alternatively continuous wave (CW) transmit signal with a bandwidth of 150 MHz are considered. The main advantage of CW systems in comparison with classical pulse waveforms is the low measurement time and low computation complexity even for a high range resolution system requirement. The paper describes two different radar systems, one in the 24 GHz domain designed as a radar network with distributed sensors and an ACC radar system in the 77 GHz domain.