The Thang Long Project Management Board said it had reported the theft to relevant authorities and begun restoring the lighting infrastructure at the National Highway 1 interchange in Dong Nai City.
The agency plans to mobilise workers, machinery and materials to replace the stolen equipment and reinstall the entire system.
Reconstruction work, including cable installation, system completion and testing, is expected to take place throughout June before the infrastructure is put back into operation.
According to the project board, more than 13 kilometres of electrical cable was stolen. Cable conduits were also dug up and damaged, leaving the lighting system unable to function.
The board has asked local authorities and relevant agencies to strengthen security measures to prevent further theft.
Similar incidents have been reported on several expressways, including the Bien Hoa-Vung Tau, Ben Luc-Long Thanh, Vinh Hao-Phan Thiet and Phan Thiet-Dau Giay routes.
Authorities warned that such thefts not only cause significant financial losses but also pose risks to road safety, particularly at busy interchanges.
The Phan Thiet-Dau Giay Expressway opened to traffic in April 2023 as part of Vietnam's North-South Expressway network.
