Studying the motion of proteins by single-particle tracking (SPT) allows to characterize how proteins dynamically interact with their environment. However, the complex cases of particles which can transition quickly between an immobile state and a slow diffusive state remained impossible to characterize accurately. In order to alleviate this issue, I have developed a method called ExTrack. After demonstrating that the method is accurate and robust, we applied it to tracks of some of our proteins of interest. The cell-wall-synthesis machinery called the 'Rod complex' is responsible for rod shape in rod shape bacteria. We found that PBP2, a core component of the Rod complex has a complex behavior which could not be distinguished with previous methods. Interestingly PBP2 needs to be in a slow diffusive state to bind. Moreover, two bound states of very different lifetimes could be distinguished. A short-lived bound state corresponds to interactions independent of the Rod complex while a long-lived bound state corresponds to active PBP2 within the Rod complex. We found that the inhibition of the Rod complex to have a strong negative effect on the stability of this long-lived state.