The objective of the IST 5th Framework EC project CarTALK2000 is to design, test and evaluate co-operative driver assistance systems to improve the overall traffic safety and to increase driving comfort and transport efficiency. Inter-vehicle communication is a key technology in the development of these systems. An example of safe and comfortable driving, as one of the goals of the project, is presented in this paper. It is meant to be a preliminary application feasibility assessment to explore inter-vehicle communication functionality in order to support further CarTALK work. At TNO a co-operative collision warning and avoidance system is developed to support the driver in longitudinal control of the vehicle. Warnings based on acceleration, velocity and inter-vehicle headway data are generated to trigger both driver and automatic vehicle actions. Inter-vehicle control algorithms are designed and evaluated in a conditioned experimental set-up with test vehicles using line-of-sight infrared communication. Preliminary results indicate a gain in response time and anticipative vehicle control capabilities. In the ongoing project the partners will further develop applications, radio communication technology and in-vehicle architecture. Standardization and socio-economic technology assessment are issues of concern to support market introduction. For the covering abstract see ITRD E122427.