*This article is based on research information as of February 2026.

1. What is the Radburn Project? A response to the automobile society

A house with a car entrance and a garden entrance

The origins of the Radburn Project date back to 1928 in New Jersey, USA. Architects Clarence Stein and Henry Wright proposed a solution to the situation at the time when the Model T Ford was becoming popular and traffic accidents in residential areas were becoming a social problem.

The essence of the Radburn system they proposed was:"Comprehensive separation of pedestrians and vehicles to maintain livability"Specifically, it consists of the following four elements:

In other words, the Radburn Plan allows children to travel safely from home to school, parks, and swimming pools along greenways without ever crossing the road. This was not just a road design technique, but a highly socially reformist urban idea that prioritized "building community" and "child safety."

The differences between the Radburn system and conventional road configurations can be summarized as follows:

*The table can be scrolled horizontally.

2. Historical Changes: The Light and Shadow of the Ideal City

From an unfinished dream to Japan's new towns

Although the Radburn Project began with noble ideals, the road to realization was not always smooth. Due to the stock market crash of 1929 and the subsequent Great Depression, Radburn was unable to realize all of his original ideas, and only about a quarter of the entire design was completed.

The original plan was for the development to cover approximately 1,200 acres, but only about 149 acres were actually built. The housing supply included only 469 detached homes, 48 townhouses, 30 duplexes, and 93 apartment buildings (all figures based on data from the International Garden Cities Institute and other sources).

However, despite its commercial setbacks, its design philosophy was systematized by prominent urban theorists such as Lewis Mumford and spread overseas. The Radburn System was adopted as the "standard solution" for new town policies in Britain after World War II, and above all for large-scale housing developments in Japan during the period of rapid economic growth.

Representative examples are Senri New Town in Osaka Prefecture and Tama New Town in Tokyo, both of which opened in 1962. However, unlike Radburn's original plan (flat separation), Japan's examples have evolved into a unique "three-dimensional separation of pedestrians and vehicles" using pedestrian decks and bridges. This functioned as a vital breakwater to protect children's lives in Japan at the time, which was called the "traffic war."

Emerging issues and "New Urbanism"

On the other hand, since the 1980s, the Radburn method has also come under criticism, with the following two main points being raised:

3. Modern Update: Barcelona "Superblocks"

Radburn's ideas were criticized at the end of the 20th century, but in the 21st century they have made a dramatic comeback in the new context of climate change countermeasures."Superilles"It's a project.

While the former Radburn method was used to regenerate low-density suburban residential areas, modern superblocks are being applied as a method to revitalize high-density established urban areas.

The magic of "3x3" and the elimination of through traffic

Superblocks are a method of redefining nine (3x3) city blocks as a single unit and concentrating through traffic on the periphery. The important thing is that they do not "completely eliminate cars."

On internal roads, the speed limit will be kept to around 10km/h, giving priority to pedestrians and cyclists, while still allowing access for residents and those handling goods. The core of the operational design is to ensure access to the building, but not to allow people to pass through the blocks (entering and exiting via a loop).

As a result, intersections that were once covered with asphalt have been transformed into "public squares" with benches and playground equipment. This has reduced noise and air pollution, and alleviated the heat island effect. The "safety philosophy" of 100 years ago has now become "environmental and health philosophy," and is fundamentally rewriting the operating system of cities.

4. Data comparison and spatial analysis

Here, we will compare and analyze the original Radburn system, the general urban structure of Japan, and the latest Barcelona system from a quantitative perspective. The table below shows how each design philosophy affects urban functions.

*The table can be scrolled horizontally.

[Reference analysis] Image of road space redistribution

We visualized the paradigm shift in spatial usage in a typical city and a city that has introduced superblocks.

The graph can be scrolled horizontally.
*This diagram is a conceptual diagram. The Barcelona discussions have highlighted the problem that while car travel is only a part of the whole, it takes up a large amount of road space (for example, 20% of travel takes up 60% of space), and have suggested that the majority of the space occupied by through traffic should be reallocated to civic space.

5. Possible expansion in Toyako Town, Hokkaido

"Winter Radburn" wall in snowy, cold regions

So, what challenges would arise if this theory were to be applied to modern-day Japan, especially to a cold, snowy region like Toyako Town in Hokkaido? The biggest obstacle, needless to say, is snow.

The cul-de-sac, a defining feature of the Radburn system, is a structure that can become a bottleneck in snow removal operations. On a normal straight road, a snow plow can pass through by pushing the snow aside, but on a cul-de-sac, the snowplow must repeatedly reverse direction and maneuver around the dead end. Furthermore, a space (snow dump) must be secured at the back of the cul-de-sac to deposit the collected snow.

In fact, in residential areas of Hokkaido, dead-end roads are often cited as a problem due to increased snow removal costs and the risk of vehicles getting stuck during heavy snowfall. Therefore, the introduction of a pure Radburn system in residential areas should be discussed in conjunction with infrastructure investments such as road heating and underground snow melting tanks, as well as a thorough snow removal plan.

Tourist Superblocks: Redefining Hot Spring Towns

However, when we shift our perspective from a "settled residential area" to an "interactive tourist destination," Radburn and the idea of superblocks shed new light on Toyako Town.

Specifically, the plan is to introduce "tourist-oriented superblocks" in the central city area of Toyako Onsen. Currently, the lakeside promenade is beautifully maintained, but the main street on the mountain side of the hotel complex still prioritizes cars, including through traffic. In this area, approximately 3x3 city blocks will be treated as a single unit, and the interior will be converted into a zone for pedestrians and emergency vehicles only (10km/h or less).

This measure is expected to create the following virtuous cycle:

• Increased mobility and economic impact:
  By becoming a "walkable city," tourists will definitely leave their hotels more often and visit restaurants and souvenir shops around town.
• Rebranding the value of your stay:
  A tranquil space free from the noise and exhaust fumes of cars enhances the resort's status. In particular, during the snowy season, being able to stroll through the snowy scenery without worrying about cars is a highly valued experience for inbound tourists.

Furthermore, in the future, low-speed mobility vehicles (green slow mobility) utilizing autonomous driving technology will circulate within the block, connecting the "last mile" from the parking lot to the hotel and each store. This could be said to be the image of a modern version of Radburn, a "hybrid superblock" that combines technology.

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