Detroit's expressways are known for traffic jams.

But I'm reasonably sure this is the first time we have had one on the Detroit River: 

One freighter is aground near Grosse Ile and another scraped bottom trying to pass her and is being examined for structural damage. 

The Lake Carriers' Association is warning about the effects of halted traffic, as many ships are too large to use the alternate channel:

 For larger ships packed with cargo, the Amherstburg Channel isn't an option, said Eric Peace, director of operations and communications for the Ohio-based Lake Carriers Association. 

"There is no other route," Peace said. "The Livingston Channel is for (loaded) downbound vessels."

The hold-up, Peace said, threatens efforts to transport goods, such as iron ore used by the auto industry, ahead of the January closure of the Soo Locks.

"We're toward the end of our season and trying to get as much as we can shipped," he said. "We're trying to stockpile and get as much as we can to them before the locks close."

Peace said several 1,000-foot vessels carrying 70,000 tons of iron ore that the association represents were waiting to get through to transport the material to southern blast furnaces that turn it into steel for the auto industry. Other Canadian ships carrying grain and wheat were also held up.

Peace noted it's critical to the national economy that the Great Lakes are able to move bulk cargo during the nine-month season.

The association, based on an analysis of slowdowns from inadequate ice breaking on the lakes between 2013 and 2014, in 2015 and 2018, resulted in an estimated loss of about $2 billion and 10,000 jobs, he said.

Chalk another one up for 2020.