Taxpayers fund local infrastructure if the reason for doing so is clear and compelling. That’s why I’m eagerly waiting to see which way voters go on a proposed amendment to Michigan’s constitution that's as close and as hotly contested as the U.S. presidential election. If passed, the measure would require residents to approve the financing and building of any new bridge or tunnel linking their state to Canada. It’s the latest — though possibly not the last — development in a seven-year, mediagenic journey involving arrests, jail time, lawsuits, millions of dollars in advertising and campaign contributions, and studies.

All over who’s going to build and control one bridge.

The problem isn’t relations between the United States and its largest trade partner but, like most disputes, money. Our busiest commercial border crossing with Canada is privately owned and operated and always has been. Except for a Minnesota bridge built by a logging company, it’s also the only private bridge. Public bridges aren’t as convenient for the 10,000 trucks that haul goods back and forth every day.

With an average per-truck toll of $15, that’s $7.8 million annually. Naturally, the bridge owner doesn’t want anything to threaten this revenue stream. But the structure's 83 years old, has only four lanes, and dumps all that heavy commercial traffic into downtown Windsor, Ontario, and a residential neighborhood in Detroit. With traffic expected to increase 43% by 2016, transportation agencies on both sides of the Detroit River want to kill two birds with one stone by building a larger bridge that connects to highways outside the cities.

The existing bridge wouldn’t be torn down, but could lose half its truck traffic. The owner claims the Michigan DOT reneged on an agreement to help build a second bridge. The DOT says the owner didn’t follow the agreed-upon design for related ramps and roads, so the agency’s justified in partnering with Canada. The courts agreed and ordered the owner to contribute $16 million to the effort. The owner appealed and lost.

Canada has twice offered to pay Michigan’s $550 million portion of the $3.8 billion design-build, public-private partnership project. But it's not quite clear what that means. Would Canada loan the money? If so, how’s this economically challenged state going to pay back its debt?

That’s when the bridge's owner turned to the legislative process, gathering enough votes for Proposal 6 to be included in the Nov. 6 ballot. Regardless what the people decide, Michigan’s governor could override them and move forward anyway. Which would probably bring everyone back into court.

Anyone who thinks infrastructure isn’t exciting isn't paying attention.