The paper presents the architecture of an unmanned vehicle called `Intelligent Pioneer' developed by the authors. The unmanned vehicle has the ability of navigating in urban environments autonomously without GPS or any other satellite navigation system. The vehicle is able to select its own routes by perceive the traffic signs and interact with other vehicles or pedestrians under the traffic rules. Various urban driving skills including lane keeping, U-turns, parking, obstacle avoidance, and merging into moving traffic have been developed for the vehicle. The vehicle attended the Future Challenge of Intelligent Vehicles in China organized by National Nature Science Foundation of China in 2010 and 2011. `Intelligent Pioneer' finished all of the competition programs and won the first position in 2010 and the third position in 2011.