The research deals with urban traffic feedback control systems. The general objective of the project is the enrichment of the complete design line of LQG controllers so that it will cover steps related to state estimation, ideally with mixed-type (continuos and discrete) states. The most important problems expected to be solved during the project are (i) general solution of state estimation in factorized form and its specialization to linear Gaussian state-space models (ii) translation of the users knowledge into optional parameters of the resulting factorized filter (iii) design of filters estimating mixed-type states and (iv) implementation and testing of controllers with state estimation on realistic simulation of traffic control problem.