Two years after commercial vehicles driving north over the Deh Cho bridge started paying tolls, the N.W.T. government says it has no way of measuring how or if the bridge is affecting the cost of living in communities like Yellowknife.

"We asked our consultants if there was a way we could measure the impact of the toll or the impact of the bridge and they basically said the cost impact of the toll is just so small that we could not track it in any meaningful way,” says Russell Neudorf, deputy minister of the Department of Transportation.

For years, politicians promised the bridge would make it cheaper to live in North Slave communities.

According to the consumer price index, the price of food has risen in Yellowknife over the past two years.

The N.W.T. Bureau of Statistics says there's no way of determining whether that’s related to the bridge.

The cost-benefit of the bridge has long been disputed. A 2002 report said the bridge would bring benefits if it cost $55 million and was completed by 2005. An updated 2007 analysis found the benefits were marginal if it cost $155 million.

In the end, what was once a public-private partnership became a government-owned bridge, opening in November 2012 with a final price tag of $202 million. No reports have calculated the benefits of a bridge at that price.

Year-round road access means companies don't have to charter helicopters to sling supplies over the Mackenzie River during freeze up and break up. Trucks are no longer delayed when water levels falls too low for a ferry to cross.

“Over time, we expect that extra service will allow businesses to operate much more efficiently," Neudorf says.

Toll revenue $400K less than expected

The tolls are expensive: ranging from about $76 to $296 based on the number of axles. The territory is also debating creating a fourth class, whose vehicles would pay even more.

The government projected that tolls would bring in about $4 million each year. Instead, toll revenues are about $400,000 short of that.

Neudorf says the government doesn't consider that a shortfall. Now that the bridge debt is wrapped into the government's overall debt, the toll money is not expected to pay for the bridge specifically. Instead, it goes into general revenues.

"As the economy increases those revenues are going to go up, but there's no link between the bridge and that revenue right now," Neudorf says.

In 2013, 16,500 northbound trucks crossed the bridge and paid tolls.

The department expects an extra 2,000 vehicles to cross the bridge this winter on their way to the diamond mines.