CERI > Cold Region Road Engineering Research Group ( Traffic Engineering Research Team ) Japanese

Snow and Ice Research Team
Road Maintenance Research Team
Scenic Landscape Research Unit



o secure the safety and mobility of traffic in cold, snowy regions, the Team studies methods for effcient and effective winter road management, analyzes the causes of traffic accidents speciffic to cold regions toward developing countermeasures, and researches road structural design and traffic management tailored to regional and traffic characteristics.


Major research topics

Research on winter road management, including the following:

  • Development of a road-icing forecast system
  • Joint development of new anti-freezing agents; evaluation of their effectiveness
  • Development of a road management method based on the quantitative evaluation of winter road surface conditions
  • Study of winter road traffic characteristics, using probe vehicles


Research on cold-region traffic accident countermeasures, including the following:

  • A system for road accident countermeasures
  • Road safety technologies, such as rumble strips


Research on structural design and traffic management of roads in Hokkaido, in-cluding the following:

  • Road structural design suited to the region and its traffic conditions.
  • Flexible road traffic management in response to weather conditions.



Research on winter road management


In cold and snowy regions such as Hokkaido, snow-covered winter greatly affects the efficiency of road traffic systems. Especially, if the roadway is icy and narrow, driving becomes difficult and unsafe. After studded tires were restricted by law (1992), extremely slippery road surface began to occur more frequently. Consequently, anti-icing agents' uses were increasing, which has raised concerns over rising maintenance costs and environmental impacts. In this research, the Team is developing an effiective and efficient winter road management system in the light of performance measurement and the management cycle in order to improve the snow and ice control activities.

Winter Road Management: Its cycle and the technologies used in that cycle



Research on cold-region traffic accident countermeasures


Hokkaido prefecture no longer ranks as the worst one prefecture in Japan for annual traffic fatalities, but the number of accidents in this prefecture has not declined. There are still many casualties. Road management requires traffic accident countermeasures that are based on scientiffic analyses, such as those involving priority indication.
Detailed analyses of accidents in Hok-kaido are performed in order to determine the causes of traffic accidents and to identify accident black spots. We conduct safety audits on such black spots. Based on these analyses, the implementation of traffic safety measures is studied.




Rumble strips installed to prevent head-on collisions on Nat’l Highway 5 in Yakumo Town (above) and Nat’l Highway 40 in Wassamu Town (below)



Research on structural design and traffic management of roads in Hokkaido


Hokkaido is typified by an extremely cold, snowy climate, and its widely dispersed population makes residents heavily dependent on road traffic to move within and between municipalities. There is the need to study structural design of roads and to constract and operate roads in consideration with the regional characteristics and traffic conditions of Hokkaido. The Team researches policies for road structure design and traffic control, in Hokkaido as follows:


  • Geometric structural design of 2+1-lane road
  • Traffic micro-simulation of 2+1-lane road
  • Performance evaluation of rural road.
  • Traffic operation by weather conditions.

2+1-lane road at National Highway 38 in Shiranuka Town


Traffic Micro Simulation of 2+1-lane road by SIM-R



Facilities and equipment


Tests are performed and data are collected using CERI equipment and facilities.

Tomakomai Winter Test Track


Skid Resistance Test Vehicle



Equipment for Continuous Skid-resistance Measurement