The flooded section, over 50 meters long with a deepest point of half a meter, is in the HC1-02 underpass. It affects traffic in both directions between Mai Chi Tho Boulevard and the Ho Chi Minh City - Long Thanh - Dau Giay Expressway. This marks the second time this underpass has flooded since its opening in February.

Following heavy rain on the evening of 10/9, several cars stalled while traversing the flooded area, prompting authorities to close the underpass. By the morning of 11/9, water had not fully receded, and units continued to deploy pumping equipment.

Cars stalled in the An Phu interchange underpass, the night of 10/9. *Photo: Giang Anh*

The underpass closure diverted vehicles to the routes above, causing widespread congestion at the An Phu interchange. This is the largest hub at the city's eastern gateway, connecting Mai Chi Tho Boulevard, the Ho Chi Minh City - Long Thanh - Dau Giay Expressway, and Luong Dinh Cua, Dong Van Cong, and Nguyen Thi Dinh roads.

A representative from the Ho Chi Minh City Management Board of Investment and Construction of Traffic Projects, the investor, stated that heavy rain lasting from the afternoon to the evening of 10/9 prevented surface water at the interchange area from draining in time, causing it to overflow into the underpass.

The project features two pumps, designed to handle water generated within the underpass. However, the excessive volume of water flowing in from outside overwhelmed the system, causing localized flooding in the middle section.

"Since last night, units have mobilized additional pumps to drain water. This morning, more equipment is being deployed to quickly restore the underpass to operation," the investor's representative said.

Congestion at the An Phu interchange due to the temporary underpass closure, morning of 11/9. *Photo: Dinh Van*

The Management Board is coordinating with the Department of Construction, Urban Drainage Company, and Fire Prevention and Fighting Police to pump water. They expect to reopen the underpass to traffic by early afternoon on 11/9.

The HC1-02 underpass is one of the main components of the An Phu interchange project. The structure is 480 meters long, directly connecting the Ho Chi Minh City - Long Thanh - Dau Giay Expressway with Mai Chi Tho Boulevard towards the Saigon River tunnel.

The underpass has four car lanes, two lanes in each direction, with a design speed of 50 km/h. It is equipped with lighting, fire prevention and fighting systems, and a pumping station. The construction package for this component is valued at approximately 342 billion dong.

After opening in early February, HC1-02 connects with the HC1-01 underpass, which will be operational from June 2025 at the Mai Chi Tho - Dong Van Cong intersection. The two underpasses facilitate continuous traffic flow between Mai Chi Tho Boulevard and the expressway, reducing conflicts at the An Phu interchange.

Design of the An Phu interchange project upon completion. *Photo: Traffic Management Board*

The An Phu interchange project commenced in late 2022, with a total investment exceeding 3,400 billion dong. The structure features three levels, including an underpass, overpasses, and a central roundabout.

The project was initially slated for completion by late 2025 but has faced delays. The Ho Chi Minh City People's Committee has approved extending the completion deadline to QIII/2027.

Giang Anh