The Green Line of the Lisbon Metro experienced a disruption on Tuesday morning due to a signaling failure. Service between Telheiras and Campo Grande stations was suspended at 7:37 AM, with no estimated time for the resumption of service. The Lisbon Metro operates four lines daily: Yellow (Rato-Odivelas), Green (Telheiras-Cais do Sodre), Blue (Reboleira-Santa Apolónia), and Red (Airport-São Sebastião). The metro typically operates from 6:30 AM to 1:00 AM.