Accessible pedestrian signals with piezoelectric sensors at signalized intersections

At signalized intersections where traffic is heavy, lighted pedestrian crossings are implemented to allow pedestrians to cross safely. At this stage, green lights are activated according to predefined times or signals from accessible pedestrian buttons. Through pedestrian buttons, the system activates only when there are pedestrians, thus speeding up traffic flow as vehicles do not have to stop when there are no pedestrians. Accessible Pedestrian Signals (APS) are devices that provide audible, vibrating, and visual warnings for all pedestrians to safely cross. The purpose of signal pedestrian buttons is to detect pedestrians in road sections where drivers are traveling at high speeds, there are heavy vehicle crossings, and there are no overpasses or underpasses, informing the intersection control device to facilitate pedestrian crossing. The "Ground Pedestrian" application used in various parts of the city by the Bursa Metropolitan Municipality stands out as the first work in Türkiye in the frame of ground-related APS. This product is an application that replaces pedestrian buttons used for pedestrians to cross at signalized intersections. The platform mounted on the ground is activated when stepped on by a pedestrian. In the scope of this thesis, a case study of the "Ground Pedestrian" was initially conducted in Bursa province. In the second stage, as an alternative to the existing APS, a new system design proposal was made. For this purpose, a new design using piezoelectric materials was developed as an alternative version of the "Ground Pedestrian", which has many advantages compared to alternatives. Piezoelectric materials, abundant in nature, generate an electric field in the direction of applied mechanical pressure. Taking advantage of this property of piezoelectric materials, a system that meets its own energy needs without requiring an external power source was planned. As a result of the experimental works, it was observed that the system created using piezoelectric material could be successfully implemented as an alternative to the existing APS at signalized intersections without the need for any electrical energy. Based on this, it is concluded that if such a design is planned at signalized intersections and a circuit that can operate with low electrical energy is designed, piezoelectric versions of future "Ground Pedestrian" platforms can replace existing ones.