Lightweight overpasses unlock HCMC gridlocks

It was in 2012 that lightweight overpasses were put on the table for discussion as traffic congestion became a gravely serious problem at the Thu Duc Intersection in the then Thu Duc District (now part of Thu Duc City) and the Hang Xanh Intersection in Binh Thanh District.

Built with steel girders, lightweight overpasses have a shorter lifespan yet cost less and take less time to build compared to those with concrete girders. When needed, the overpass can be disassembled and moved to other places.

Though many experts were against the idea of building such overpasses, the city decided to go for it given the urgency of solving congestion at the two intersections.

Costing VND277 billion ($11.83 million) and VND188 billion, respectively, the two overpasses in Thu Duc and Binh Thanh were put into use in January 2013 after just six months of construction.

The overpass (L) at Thu Duc Intersection in Thu Duc City runs next to the metro line, 2022. Photo by VnExpress/Quynh Tran

The overpasses were originally built for both motorbikes and autos but later on, due to the high volume of autos using the one in Thu Duc, authorities banned motorbikes in the interests of traffic safety.

With the two projects proving their efficiency, city authorities moved on to spend VND122 billion the very next month on building the third overpass with a steel girder at Lang Cha Ca Roundabout near the Tan Son Nhat airport in Tan Binh District.

Completed after 80 days, the bridge allows vehicles to travel from Cong Hoa to Hoang Van Thu without having to share the space beneath with those moving in the opposite direction.

Within April 2013, the city started work on three other lightweight overpasses at a total cost of more than VND1 trillion at: the meeting point of Nguyen Tri Phuong, Ba Thang Hai and Ly Thai To in District 10; the intersection of Cong Hoa and Hoang Hoa Tham streets, which is less than 3 km from Tan Son Nhat airport; and the bridge at Cay Go Roundabout in District 6, which has two branches and took longer to build (until October 2013).

The overpass at Lang Cha Ca Roundabout near Tan Son Nhat airport in Tan Binh District, June 2022. Photo by VnExpress/Gia Minh

Four years later, HCMC expended more than VND1.1 trillion to construct two more overpasses with steel girders at major intersections around the Tan Son Nhat Airport: Go Vap Roundabout and Nguyen Thai Son – Nguyen Kiem – Hoang Minh Giam intersection; as well as on Truong Son Street in front of the airport.

Phan Cong Bang, deputy director of the municipal Department of Transport, said lightweight overpasses have played a significant role in easing congestion at major intersections across the city.

At some intersections like the Go Vap and Cay Go roundabouts, traffic jams have been reduced by 70-80 percent, he said.

"In the past 10 years, the number of congested points around the city has been reduced to 18 from almost 40, with some of the points removed from the (congestion prone) maps thanks to the overpasses," he said.

Currently, the Thu Duc Intersection has 50,000 autos passing by every 24 hours and the figure for Lang Cha Ca Roundabout is more than 40,000 autos, according to the department.

The city plans to continue using the nine overpasses until 2030.

Vehicles move past the Nguyen Thai Son – Nguyen Kiem – Hoang Minh Giam intersection near Tan Son Nhat airport in Tan Binh District, May 2022. Photo by VnExpress/Gia Minh

Chu Cong Minh, a traffic infrastructure expert at the HCMC University of Technology, said an overpass with a steel girder is a temporary solution to cope with the severe traffic jam situation in the city.

These bridges cost lower and do not take long to build because they are not permanent bridges.

"They are lightweight overpasses, but still basically meet the demand of large trucks, such as those that usually travel through the Thu Duc Intersection," he said, referring to the border area between HCMC and industrial neighbors Binh Duong and Dong Nai Provinces.

However, he said the number of vehicles using those overpasses is constantly increasing and many of them are getting overloaded; so the city needs to invest in completing traffic intersections or combine steel overpasses with underground tunnels, he said.

Ho Chi Minh City plans to build 102 main traffic intersections – 68 on ring roads, highways and national highways and 34 in the inner-city area. However, only 29 have been completed to date.

Recently, the municipal transport department proposed that fund be allocated soon for 16 major traffic intersections in the next three years.