A system and methods are disclosed for providing integrated software development environment for the design, verification and validation of advanced automotive safety systems. The system allows automotive software to be developed on a host computer using a collection of computer programs running simultaneously as processes and synchronized by a central process. The software disclosed uses separate synchronized processes, permitting signals from disparate sources to be generated by a simulation running on the host computer or from actual sensors and data bus signals coming from and going to actual vehicle hardware which is connected to their bus counterparts in the host computer on a real-time basis. The methods provide a data model that first extends the capabilities of the physical data model and then translates, gates, optimizes, fuses, filters and manages the physical representation of the logical model into a state estimation of the situation around the vehicle.