Spate of Incidents Involving Fallen Trees: Strengthening Inspections Is Crucial to Prevent Recurrences

Editorial

17:08 JST, March 22, 2026

There has been a spate of accidents in which trees planted in parks or along streets suddenly fell and trapped pedestrians. The central and local governments should strengthen inspections and accelerate efforts to take measures such as felling dangerous trees.

A cherry tree that was more than 10 meters tall collapsed in Kinuta Park in Setagaya Ward, Tokyo, earlier this month, trapping a woman in her 70s who was walking nearby.

In 2024, a man in his 30s who was on a pedestrian path died after being struck by ginkgo branches that snapped off at a height of about 10 meters in Hino, Tokyo.

According to the Land, Infrastructure, Transport and Tourism Ministry, an average of 5,200 roadside trees have fallen annually. The collapses were caused by typhoons, strong winds, decay and disease, among other factors. Aside from trees along streets, incidents have also occurred in parks and shrines.

It is not rare for a tree to fall onto a moving vehicle or for a fallen tree to touch a power line and cause a blackout.

Gales tend to occur in spring, in particular, as low-pressure systems develop rapidly. It is difficult for pedestrians and vehicles to avoid trees that suddenly fall. As such a situation is extremely dangerous, measures must be implemented urgently.

As automobile traffic surged during the postwar period of rapid economic growth, trees such as ginkgoes and zelkovas were planted along streets nationwide as a measure against noise and exhaust fumes. These trees preserve the townscape and block strong sunlight, while their roots are effective in strengthening the foundation of the ground.

However, many of these trees are aging after about half a century since they were planted. Many trees have become weaker after their branches and roots were damaged due to factors such as land readjustment and road-widening projects.

Checking a tree’s condition requires specialized knowledge to identify diseases and other issues by observing the structure of its bark and branches. It is important for arborists and others to regularly inspect the condition of trees and, if they determine that there is a high risk of the tree falling, to proceed with felling or replanting.

Recently, some companies have developed systems that analyze images of trees using artificial intelligence technology to confirm their condition. Local governments and such companies should deepen cooperation to diagnose trees effectively.

However, many local governments are struggling to tackle this issue due to limited manpower and budgets. In a national survey, only 40% of local governments said they regularly inspect trees along streets and in parks.

Failing to inspect roadside trees not only poses a risk of them falling but could also lead to problems such as overgrown branches obscuring traffic lights and road signs.

Roadside trees, which add color to towns, enrich people’s lives. It is not the end once trees are planted. Ways to coexist with these trees for a long period of time should be considered. It is also essential to improve support measures, such as the central government providing management guidelines to local governments.

(From The Yomiuri Shimbun, March 22, 2026)