The Bellingham Herald reports that border policy researchers at Western Washington University have been observing the number of Canadian and U.S. vehicle license plates at various points along the I-5 corridor.
The research began before the Skagit bridge collapse to get a better understanding of Canadian shopping activity in the region.
A license plate survey done in June after the bridge collapse found that the proportion of Canadian plates at a Costco in Marysville dropped by 80 percent compared to March.
Five of the six retail areas that were surveyed south of the Skagit bridge saw a decrease of more than 40 percent.
David Davidson at the university's Border Policy Research Institute says the survey provides a snapshot on what happens when a key piece of transportation infrastructure is disrupted.
The Small Business Administration announced in June it was making low-interest disaster loans available to small businesses hit in the pocketbook by the collapse.
The declaration covered Skagit County and the adjoining counties of Chelan, Island, Okanogan, Snohomish and Whatcom.
Karen Mills, administrator of the U. S. Small Business Administration, said the agency acted under its own authority to declare a disaster in response to a request it received from Gov. Jay Inslee.