During the last decade, the concept of smart cities is gaining popularity, and many cities all around the globe are adopting it. Lately, the Smart Pedestrian Crossing (SPC) idea has become an important part of the smart city concept. The main objective of the SPC is to achieve a safe and smooth traffic flow of pedestrians and vehicles in the smart city. In this paper, we present a simple yet efficient localization system which is suitable for locating people over a pedestrian crossing. By adopting the proposed localization system, the people flow over the pedestrian crossing can be observed. Consequently, a safe and efficient traffic flow in the smart city can be achieved. The proposed system utilizes Internet of Things (IoT) transceivers that are carried by the pedestrians or embedded in the pedestrians' smart devices. These transceivers can be activated to transmit a signal every few seconds when the pedestrian passes over a pedestrian crossing. These periodic signals will be received by a single Angle of Arrival (AoA) estimation system to estimate the direction of the pedestrian. Furthermore, the pedestrian direction and the environmental features of the pedestrian crossings are utilized in a 1D particle filter to estimate accurately the pedestrian's location. The proposed system has been validated experimentally in the smart zone of Antwerp city. The experimental results reveal that the proposed localization system can provide an accurate, cost effective and reliable localization solution to this specific problem without violating the pedestrian privacy. INDEX TERMS AoA, angle of arrival, DoA, direction of arrival, Internet of Things, IoT, environmental features localization, smart pedestrian crossing, smart cities, particle filter, SAGE algorithm.