(25) Traffic calming in Tokyo 交通静穏化

The term “traffic calming” refers to measures to slow or otherwise influence the behavior of drivers in order to make roads safer for other drivers, pedestrians, and cyclists. This is achieved through a variety of methods such as speed bumps (aka “sleeping policeman”) or curb extensions. In Japanese, traffic calming is translated as 交通静穏化 or phonetically from the English as トラフィック・カーミング. In Tokyo, many side streets don’t require additional traffic calming features, as the narrowness of such roads seems to be enough to keep speeds down; the perceived safety of Tokyo’s side streets is evidenced by the many people who walk near the middle of the road, moving to the side as cars approach (see previous post: Narrow streets with people walking in the road).

A child rides a miniature car on a narrow Tokyo street, next to a family of four.

In some cases, more explicit measures are taken to slow the flow of traffic. Here are three notable traffic calming techniques in the Tokyo area:

(1) Fake barriers

An interesting traffic calming measure is known as an “image hump” イメージハンプ or “image bump” イメージバンプ; these are painted images on a street’s surface that resemble 3-D objects such as curbs, barriers, etc. See the following example from Yanaka, Tokyo, (map):

This traffic calming technique is also called 「立体路面標示」 “3D pavement marking” or 「立体減速標示」 “Dimensional deceleration sign”. One company, Sekisui Jushi Corporation (SJC) 積水樹脂株式会社, sells this product with the trade name “Solid Sheet” 「ソリッドシート」. SJC’s 2012 Annual Report describes their product as “Sheeted thermoplastic road markings.”

See the following image hump examples from Shiba 2-chome, Minato-ku, Tokyo (map). From certain distances the image humps resemble actual physical curbs; this illusion dissolves when viewed from the side.

More views from the same neighborhood:

**(2) Meandering 蛇行 (dakō) road design**

Another street calming technique is to modify an otherwise straight road and create an intentionally meandering 蛇行 path; an example from central Yokohama (map):

(3) “Visual sidewalks”

I refer to the last example as “visual sidewalks”. These are designated walking paths that are at the same elevation as the road surface and are not separated by any curbs or barriers. These paths can be painted (often green) or can be paved with bricks or a different material from the main road material. Here is an example from Toshima-ku (map):