This is what it's like to do construction work on the Ambassador Bridge

A group of about 30 people have spent the last three years reinforcing the 90-year-old Ambassador Bridge, as thousands of vehicles pass behind them and the daily life of those in Windsor, Ont. continues below.

"They're working under conditions that a lot of people would find frightening," said Mike Sorrel, a project manager with Windsor-based construction company Matassa Incorporated.

Sorrel, standing beside the ramp portion on theCanadian sideof the iconic Ambassador Bridge, said they love the job, butfor some of his team it took some convincing.

"Originally when we first got this project, they thought this was going to be a struggle:trucks going by them millimetres away from them but these guys love the work," said Sorrel.

Bridge could last another 75 years

Sorrel's team is working away from the water, replacing steel joists and pouring concrete into a curb while replacing both the railing and lighting along the bridge.

"Things that are going to make this bridge last another 75 years," said Sorrel, adding that the bridge is in "great shape" and essentially revamped from the water's edge to the Canadian entry point.

The entire project has been underway while traffic carries on behind them, up to8,000 transport trucks and 68,000 vehiclesmoving behind them daily, which can put a lot of pressure on the group.

The bridge is also shifting with the weight and wind while they're doing the work.

"When you are standing on it there's movement," said Sorrel, noting they'vehired people specifically for this project, one that he calls"high-risk" and unlike any other Matassa has taken on before.

"We've assembled a cast that we thought would work good on this and it has worked out really good."

'World of difference'

Sorrel believes the work on the Canadian side should be finished by the end of the year, which is when he hopes to start work on the American side of the bridge.

Even though there's still work to be done, Sorrel said drivers can already spot the improvements.

"It's a world of difference from what it was four years ago, it's a nice looking structure."

That's a long way from 2016 when Transport Canada issued an emergency directive to the owner of the bridgeafter finding safety deficiencies on the Canadian side of the Ambassador Bridge

StanKorosec,director of security and Canadian government relations for the Canadian Transit Company, said these improvements are about regular maintenance and will add decades to the lifespan of the 90-year-old bridge.

When he looks up at the bridge, he sees a feat of engineering and construction.

"It was quite an incredible feat," said Korosec, who grew up in Windsor and was once vice-president of operations at the Blue Water Bridge in Sarnia.

Korosec's mind goes to the safety measures that have changed since the construction of the bridge in 1929. Black and white photos of the original construction project show people seemingly dangling from the bridge without hardhats as they work at times 40 metres above the Detroit River.

That's about the height of a 12 story building.

Bridge stays open during the work

Korosec said the project costs "millions of dollars" and didn't give an exact figure. He said a key component of the project is doing the work in a way that doesn't force the bridge to shut down.

"We can't shut down the bridge. Too many people rely on it to go to work, to go to events, back and forth across the border and not to mention the economy, especially with the just-in-time delivery," said Korosec.

He said the Ambassador Bridge is something he took for granted growing up, but fully appreciates now that he's so close to the project.

"The bridge is really alive, it moves.It's supposed toand you really just feel the power of the structure."

Here's a look at the original construction of the Ambassador Bridge in the1920s: