On February 12th (ie, December 25th of the lunar calendar), thousands of cars of people from southern provinces returning to their hometowns for Tet through National Highway 1 caused serious congestion in the South and North areas of Deo Ca tunnel.

The line of cars stretched for many kilometers, so many drivers had to turn off their engines and get out of the car to rest because they waited too long.
According to records, the road belonging to the Deo Ca tunnel project, the section from the Co Ma pass intersection to the Deo Ca tunnel entrance, passing through Dai Lanh commune, Khanh Hoa province, experienced prolonged traffic jams from early morning.

Thousands of cars lined up, moving little by little. As it got closer to noon, the traffic volume continued to increase, making the congestion situation increasingly serious.
Many drivers said that they have to stand still for dozens of minutes, even hours, and are forced to turn off the engine to save fuel.
In the Deo Ca tunnel toll station area, vehicles move very slowly, each car only moves meter by meter.

Mr. Tran Dinh Trung - a driver from Nha Trang - said: "From the southern gate to the Deo Ca tunnel toll station, it took me 3 hours. Now I see the station but I don't know when it will be my turn. Traffic jam right at the toll station for several hours without discharging the station is very tiring.
Due to prolonged traffic jams, many families, when reaching the section with the gas station, took the opportunity to stop to rest, eat and drink and wait for the traffic situation to stabilize before continuing their journey.
Representatives of Ninh Hoa Traffic Police Station (Traffic Police Department, Khanh Hoa Provincial Police) said that the cause of congestion is due to the large volume of vehicles pouring in at the same time, while vehicles concentrated through the toll station, causing increased traffic pressure.

To limit the risk of overload, especially at the end of the Van Phong - Nha Trang expressway, the traffic police force has prepared remote regulation plans.
When the density of vehicles increases, traffic police will proactively guide vehicles to leave the expressway to National Highway 1 at intersections with National Highway 26, National Highway 27C... to reduce pressure on the Deo Ca tunnel area.
According to functional forces, in the days leading up to Tet, the number of vehicles passing through Deo Ca tunnel has doubled compared to normal days, mainly in the South - North direction, when people from Ho Chi Minh City, Dong Nai and southern provinces return to their hometowns for Tet. In the opposite direction, traffic is basically smooth, without congestion.