The unblocked reliability of urban road network directly impacts the effectiveness of city traffic management. First, a bi-level programming model based on the urban road network unblocked reliability concept is presented, and its upper-level model is to minimize the total investment and make the network to be system optimization at the same time, the lower-level model is a standard network equilibrium model satisfying WORDRAP's first equilibrium rule. Then, a GA is adopted to solve this problem. Finally, the network of JinFu intersection in ChengDu has been regarded as an example to verify the validity and feasibility of model and algorithm, explaining the research of unblocked reliability can provide technology and decision-making support for urban road network planning management.