The Metropolitan Transport Corporation (MTC), Chennai, on Saturday launched a GPS-based bus stop announcement system to guide passengers in alighting at their respective destinations. The system was launched by Chepauk-Thiruvallikeni MLA Udhayanidhi Stalin, son of Chief Minister M K Stalin, here, in the presence of State Transport Minister S S Sivasankar and Hindu Religious and Charitable Endowments Minister P K Sekar Babu. Shortly after the launch, Udhayanidhi, accompanied by the ministers, travelled in a MTC bus.