Crews are at work 24 hours a day to finish installing 2,807 lights on the Jacques-Cartier Bridge.

The $40-million project is part of Montreal's 375th and Canada's 150th celebrations this year.

Technicians were putting the system through its paces Tuesday night, changing the hue of the bridge from ice blue to summer yellow in one second.

The pulsating LED lights will reflect the seasons, but will also interpret live data such as mentions on social media, the daily weather and traffic.

At this point, 70 per cent of the span is lit -- all that's left are the extremities and the pillars.

The installation opens May 17 and is planned to run for 10 years.

“If it's rainy outside or it's a big storm it would be great to see a storm on the bridge,” said Gabriel Pontbriand, creative director of Moment Factory. “We tell a story with light, and to tell a story with light, it's quite abstract but now we can see and for a creative team, it's a great moment. We are very excited about it to see some first result after three years of work.”

Wiring the bridge requires more than 10 kilometres of cables and 10,000 separate mounting systems.