A proposal to reserve the left lane for overtaking on expressways has gained attention in Vietnam, with supporters arguing it would improve lane discipline and traffic efficiency.

The idea is worth considering, but introducing it now might be premature due to differences in transportation systems.

I had two very different experiences on the same road.

I drove on the Lang–Hoa Lac Expressway where the speed limit was 60 km/h, but I was overtaken by a vehicle that entered the emergency lane and cut in front of me.

I had to slam on the brakes to avoid a collision.

When I pulled alongside the other driver, he shouted at me for driving too slowly.

I chose not to argue and continued my journey.

On another occasion, I had the opposite problem.

I needed to overtake a slower vehicle, but all lanes were filled with traffic.

A dump truck and a container truck were traveling side by side in the left and middle lanes, blocking all traffic behind them.

These experiences show that the debate over overtaking lanes involves more than just lane discipline.

Infrastructure in Vietnam is uneven.

Vietnam's expressway network varies in design and operating conditions.

Some expressways have two lanes in each direction, while others have three, and traffic volumes differ greatly.

Vietnam is also experiencing rapid motorization.

Hanoi has over 1.2 million cars, and vehicle ownership is rising sharply in other cities.

Major expressways often experience heavy congestion during peak periods.

The principle of keeping right except to overtake works best when there is enough space to overtake.

When all lanes are saturated with traffic, the left lane becomes another travel lane rather than an overtaking lane.

Any overtaking-only requirement should be considered on a road-by-road basis.

Rules alone are not enough to improve traffic.

Vietnam is still developing its expressway driving culture.

Many motorists are still getting used to expressway driving and often make mistakes like staying in the left lane unnecessarily.

Introducing a keep right except to overtake rule would require more than just changing traffic regulations.

Road signs, driver education, and enforcement procedures would need to be updated.

Effective enforcement would require distinguishing between legitimate overtaking and unnecessary left-lane occupation.

Achieving this would depend on robust camera systems and strong enforcement capacity.

Existing traffic violations like unsafe lane changes are already prohibited but not consistently enforced.

The immediate challenge is to enforce existing rules rather than introducing new ones.

Strengthening monitoring systems and improving compliance may yield greater benefits.

Learning the system is more important than just one rule.

The keep right except to overtake principle is part of a broader transportation system.

In countries where the rule works, it is supported by standardized road design and intelligent transportation systems.

Removing one rule from the system does not guarantee the same outcomes elsewhere.

Vietnam could start by expanding pilot programs on expressways with suitable infrastructure.

Authorities could establish clearer speed ranges for each lane and strengthen enforcement against unnecessary left-lane occupation.

The goal should be to build a flexible traffic management system.

When traffic volumes are low, the left lane can primarily serve overtaking traffic.

When demand approaches road capacity, intelligent systems could adjust speed limits and allocate traffic across lanes.

This would require investment in smart transport infrastructure like cameras and traffic sensors.

The debate over left-lane rules extends beyond traffic management to policymaking.

International experience offers valuable lessons, but its value lies in understanding the conditions that made those rules successful and adapting them to Vietnam's context.

Tu Giang