Thank you, Mr. Speaker. This is a reply to a question asked by Mr. McLeod on February 28, 2000, relating to the Mackenzie River crossing in Fort Providence.

The Department of Transportation uses the Gold formula to calculate the thickness of ice necessary to support the weight of a truck on its winter roads and ice bridges. Dr. Lorne Gold developed the formula from his studies of winter logging roads in northern Quebec in the 1950s. Dr. Gold is Canada's foremost authority on the use of ice as an engineering material for transportation and has been the standard for design for many years.

The bearing strength of ice is not related to traffic volume. If the ice is strong enough to support the passing of one truck, it is strong enough to support any number of passes. Increased truck traffic does, however, damage the surface of the ice road by causing ruts. Many other factors, of course, also play a role and these are described in the Department of Transportation's manual, A Field Guide to Ice Construction Safety. Higher truck volumes increase the department's maintenance efforts in blading, flooding and smoothing of the travelling surface. If the wear and tear at a crossing becomes excessive, the department would open a second parallel crossing while it repaired the first.

So, in answer to the Member's question, heavier truck traffic does not effect the initial construction of an ice crossing, but it does impose greater maintenance costs on the Department of Transportation through the operating season.