Connected Cruise Control (CCC) is an in-car driver support systems that aims to improve throughput in dense motorway traffic by advising drivers how to drive. The system is currently under development within a HTAS project. It will integrate lane advice, headway advice and speed advice. CCC will not take over vehicle control. This makes its effectiveness dependent on the drivers ability and willingness to comply to the advice. In the present study we used a think-aloud protocol, during the first on-road field-test of the CCC system, to assess drivers' initial reactions to the advice. From the transcripts we extracted factors that can influence compliance to tactical driver advice. These factors can be used to formulate hypotheses about driver compliance to CCC. © 2013 IEEE.