Research Idea Details

Research Idea Scope

Snow avalanches can have
catastrophic effects on highway travel by blocking roadways entirely as well as
the potential for both property damage and loss-of-life consequences.  There are also severe economic consequences
associated with this hazard.  It may take
hours to days to open roads which are blocked by avalanches, as opposed to
minutes to hours for clearing roads with typical snow and ice control
operations.  How future changes in
climate will affect the risk of avalanche ranges from an increased risk to a
decreased risk due to low snow pack. 

A variety of effective
roadside treatments and mitigation measures have been developed to prevent or
control avalanches.  Such measures
include snow bridges and snow sheds, active avalanche forecasting programs, and
mitigation using explosives for avalanche protection. Substantial research in
several countries has done in the engineering design of these treatments.  This has resulted in a variety of
publications, design guidelines, and many miles of roadway – worldwide – where
avalanche hazards are successfully managed.

While successful
treatments have been developed, empirical knowledge is often used to close
roads due to avalanche risk. Recent developments in numerical simulation,
real-time modelling, and digital mapping allow the possibility of pro-active
evaluation on a highway network basis to track and forecast avalanche risk
through a winter season.

Urgency and Payoff

The frequency of wet snow
avalanches may also increase due to an increase in average temperature and an
earlier onset of spring-like conditions. However, wet snow avalanches are
difficult to predict because the water movement in a snowpack is a complex
process. A simulation model has been developed to simulate the water movement
in a snowpack in Switzerland.

The Swiss Federal
Institute for Snow and Avalanche Research has developed blowing snow models
used for avalanche forecasting. This information is helpful for decision making
for both winter driving and winter road maintenance.

An avalanche forecast
system using the SNOWPACK model has been developed in Japan.  The SNOWPACK model was developed in
Switzerland and can estimate snowpack layering from weather data. SNOWPACK is
also used operationally in Switzerland and has been tested in the U.S. and
other countries as well. 

Another snow model,
CROCUS, was developed in France. The model is used for developing an avalanche
forecasting system in Norway.

Hence, highly reliable
forecast models of avalanches are essential to provide better winter road
services as the climate changes.  A
synthesis on snow pack simulation and forecasting models in snow science will
identify those that can be used to evaluate avalanche risk along roadways and
to help highway agencies reduce such risk to travelling safety and mobility.
This topic will review these models and consult the feasibility of using these
models for snow avalanche controls on highways.

This topic has been
modified from the submittal to the 2013 NCHRP Synthesis.  It is supported by TRB Winter Maintenance
Committee, AHD65.