After the Opening of the North Horizontal Tunnel, Has Congestion on the Yan’an Viaduct, Also a Major East-West Transportation Route in Shanghai, Been Alleviated?

On August 2nd this year, the eastern section of the main line of Shanghai’s Beiheng Tunnel was opened to traffic. This marks the full opening of the 19.1-kilometer-long Beiheng Tunnel after a decade of construction.

On November 29th, reporters from The Paper learned from the Shanghai Transportation Commission that in the three months since its full opening, the traffic pressure on Yan’an Viaduct and the northern section of the Inner Ring Road during weekdays has been alleviated to some extent, and the traffic flow of the road network has become more balanced. Meanwhile, in the early stages of the opening of the eastern section, there was some congestion at nodes such as Xinjian Road, Huangxing Road, and the east entrance of Tianmu Roundabout, as well as at ground intersections connected to the ramps. Through measures such as adjusting traffic organization and optimizing signage, the situation at some of these congested points has improved.

The photo shows the Beiheng Tunnel. (Provided by the Shanghai Transportation Commission)

Traffic Conditions Improve, Diverting Traffic from Yan’an Viaduct

The Beiheng Tunnel connects six administrative districts: Changning, Putuo, Jing’an, Huangpu, Hongkou, and Yangpu, spanning 20 streets and 64 roads. It is the second east-west transportation “artery” in Shanghai since the completion of the Yan’an Viaduct in 1999. The Beiheng Tunnel is equipped with 8 pairs of entrance and exit ramps, and nearly 80% of the tunnel is underground, making it the longest underground road in a city’s core area in the world.

According to the latest data analysis from the Traffic Command Center of the Shanghai Transportation Commission, after the full opening of the Beiheng Tunnel, its functions have been further utilized, basically achieving the planned construction goals. The current traffic situation has improved significantly and is gradually stabilizing.

Firstly, it balances regional traffic flow and enhances the resilience of the backbone road network. Three months after the opening of the eastern section, the road network capacity in the northern part of the central area has increased. The daily average traffic flow on Yan’an Viaduct and the northern section of the Inner Ring Road during weekdays has decreased by 6.9% and 5.1% respectively compared to before the opening, alleviating traffic pressure to some extent. The traffic flow of the road network is more balanced, and the resilience of the city’s backbone road network is further enhanced.

Secondly, it connects six administrative regions, meeting the development needs of the city’s east-west axis. The Beiheng Tunnel diverts traffic from Yan’an Viaduct, improving the reliability of east-west transportation in the central city and further meeting the development needs of the city’s east-west axis. Currently, the eastern section serves about 80,000 to 90,000 vehicles per day, with a gradual growth trend since its opening. The western section serves about 150,000 vehicles per day, an increase of 17% compared to before the opening of the eastern section.

Thirdly, the function of Hongqiao Hub is further enhanced. The areas along the route are more closely connected to Hongqiao Hub, and the travel time from Yangpu Binjiang and Hongkou North Bund to Hongqiao Hub is shortened by 15 minutes, improving the accessibility of the transportation network.

Fourthly, it connects multiple river-crossing tunnels, enhancing communication between the two sides of the Pujiang River. The traffic flow of the river-crossing tunnels closely related to the Beiheng Tunnel has increased compared to before its opening. The daily average traffic flow on Zhoujiazui Road Tunnel and Xinjian Road Tunnel during weekdays has increased by 20.1% and 4.1% respectively compared to before the opening, enhancing communication between the two sides of the Pujiang River.

The Traffic Volume on the Eastern Section’s Main Line Increases, but the Growth Rate Gradually Slows Down

According to the latest data analysis, the eastern section of the Beiheng Tunnel has shown some characteristics in traffic operation over the past three months.

The traffic volume on the eastern section’s main line has increased, but the growth rate has gradually slowed down. The daily average traffic volume on the eastern section’s main line from August to October was 76,700, 82,500, and 86,500 vehicles respectively, with month-on-month growth rates of 7.6% and 4.8% respectively. The growth trend is gradually slowing down.

The eastern section of the Beiheng Tunnel experiences “double peaks” during weekdays and a “single peak” on afternoons of weekends. The traffic flow during weekday morning peak hours is higher than that during evening peak hours.

The weekly peak traffic volume at the ramps mostly occurs on Fridays. Among all the ramps in the eastern section of the Beiheng Tunnel, the ramp at Zhejiang Beilu has the highest traffic volume, with a daily traffic flow of 35,200 vehicles. This is followed by the ramps at the west side of Xinjian Road and Huangxing Road, with daily traffic flows of 28,300 and 26,700 vehicles respectively. The ramp at the east side of Xinjian Road has the lowest traffic flow, with a daily traffic flow of 20,300 vehicles. The weekly peak traffic volume at each ramp mostly occurs on Fridays, which is basically consistent with the peak traffic volume on the main line. The daily traffic flow on weekends is slightly lower than that on weekdays.

Congestion at Key Nodes Improves

In the early stages of the opening of the eastern section, there was some congestion at nodes such as Xinjian Road, Huangxing Road, and the east entrance of Tianmu Roundabout, as well as at ground intersections connected to the ramps. To address this, the Shanghai Transportation Management Department took a series of measures such as adjusting traffic organization and optimizing signage, resulting in improvements in congestion at key nodes.

The congestion at the Xinjian Road node has been significantly alleviated. By adding a straight lane at the east and west exit ramps and improving traffic organization and guidance, the congestion at this node has been effectively alleviated.

The queuing at the east entrance of Tianmu Roundabout has been slightly alleviated. In the early stages of the opening of the eastern section, due to the increase in traffic flow at the east entrance of the interchange and the saturated operation of the north-south viaduct’s main line, there was queuing and slow moving traffic at the east entrance of Tianmu Interchange, mainly during evening peak hours. In the third month after the opening, as citizens gradually adapted, the traffic flow during evening peak hours stabilized.

The exit ramp at Huangxing Road experiences constant slow moving traffic during peak hours. In the early stages of the opening of the eastern section, due to the overflow of queuing vehicles from the on-ramp at Yangpu Bridge, there was queuing and slow moving traffic at the exit ramp at Huangxing Road. After the school semester began, with the combination of commuting and school travel, the queuing vehicles at the exit ramp at Huangxing Road during peak hours partially extended to the main line of the Beiheng Tunnel, resulting in longer queuing durations.