Research results

"Color Point-Book for Hokkaido"
- A Guide to Color Consideration for Roadside Structures in Hokkaido and Cold-Snowy Regions -

  In Japan, "Guidelines for Landscape Management of Traffic Barriers and Fences" was formulated first in 2004 through Ministry of Land, Infrastructure and Tourism in Japan, and as an advanced one, "Guidelines for Landscape Management of Roadside Structures" came in 2017. They give basic considerations about issues from visual aspects and desirable colors of roadside structures, and show the several standard colors that are recommended for such structures (first three colors (dark-gray, dark-brown and gray-beige) in the guidelines of 2004, and added one color (off-gray) in the guidelines of 2017). But the road environments and landscape situations in Hokkaido differ significantly from those in the rest of Japan or in regions without snow and ice. So the colors that are suitable for roadside structures in Hokkaido should differ from those of the national standard such as noted above.

  *1 "Roadside structures" here refers to traffic barriers, fences, lampposts, signs, over-bridges and shelters on the roadside.

  Therefore, we researched on the colors suitable for roadside structures in Hokkaido. Through the research, we investigated colors used and exists in Hokkaido, and conducted color evaluation tests using small color samples and participants.

  In 2018, we published these results as the "Color Point-Book for Hokkaido".Through this point-book, we made an explanation on the characteristics of the roadside scenery in Hokkaido, and pointed out current issues and possible solutions that are related to colors of roadside structures from the aspect of visual amenity.The point-book also presents a tentative proposal on the colors that are desirable for roadside structures considering typical road environments and scenery in Hokkaido.


Major points of the proposal in the point-book

  1. The Dark-brown color does not always suit the road environments in Hokkaido.

  There stretch vast land and land-use around the roadside of Hokkaido. So the roadside structures are seen often against backgrounds of bright colors of the sky or landscapes much far away. There's also a snowy season in which all the sceneries are covered with bright snow (refer to the photo below). In light of the above, in Hokkaido, structures with dark colors, including dark-brown, stand out in the scenery. In a snow-covered achromatic landscape, even dark-brown color may look vivid.


▲ A dark brown marker post interferes with an open landscape. It attracts more attention than utility poles that are larger than marker posts.
▲ A dark brown marker post interferes with an open landscape. It attracts more attention than utility poles that are larger than marker posts.
▲ Color simulation: The dark brown lamppost and traffic fence on the right (photomontage) stand out in comparison to the galvanized-finish lamppost on the left.

▲ Dark gray 10YR3/0.5 applied to a lamppost on National Route 230 in Jozankei
▲ Dark gray 10YR3/0.5 applied to a lamppost
on National Route 230 in Jozankei


  2. Achromatic dark-gray color is the best option among the three standard colors recommended in the national guidelines. In some cases, galvanized-finish is another option.

  In the achromatic landscapes in the snow-covered season, achromatic colors blend well with the achromatic scenery of the season. Dark-gray is the only achromatic color among the three standard colors in the national guidelines. Achromatic colors also blend with scenery full of colors in summer. Besides, in winter in Hokkaido, the painted surfaces of roadside structures are sometimes damaged during snow removal operation, and wearing off of painting detracts from the scenery. This problem is mitigated when roadside structures are painted in achromatic colors because medium-bright achromatic colors of galvanized surfaces stand out less even in the worn off painting situation. Therefore, for the roadside structures in Hokkaido, the dark-gray color should be given priority over the dark-brown color. In some environments where light achromatic colors are desirable, galvanized-finish is also applicable.

  *2 Off-gray color, which was newly added in the national guidelines of 2017, is excluded here because this color has been applied to few roadside structures and thus has not been examined or evaluated enough.


  3. Greenish-gray color as an option.

  Many elements in the scenery of Hokkaido, such as sky, snow and distant mountains, are looked bluish or greenish. Thus, bluish or greenish colors are more suitable than reddish or brownish colors for roadside structures in Hokkaido. There exist several roadside structures in Hokkaido to which greenish-gray (Munsell color chroma = 1.0) has been successfully applied.

  On our research, we conducted color evaluation tests in 2016 and 2017. In these tests, the color samples as a mock-up of roadside structures were evaluated against multiple background situations. From the result, dark-gray color was the most favored color, followed by greenish-gray color (5GY3/1).


▲ Greenish-gray 5G4/0.8 <BR>Bridge railing on National Route 453 ▲ Blue-greenish gray 5BG5/1<BR>Lamppost on Crystal Bridge in Kitasaito, Asahikawa
▲ Greenish-gray 5G4/0.8
Bridge railing on National Route 453
▲ Blue-greenish gray 5BG5/1
Lamppost on Crystal Bridge in Kitasaito, Asahikawa

  The "Color Point-book for Hokkaido" can be downloaded from our website.Scenic Landscape Research Team in the Civil Engineering Research Institute for Cold Region.

  (http://scenic.ceri.go.jp/manual.htm)


(Contact:Scenic Landscape Research Team, CERI)