Work began Friday on the conversion of Jarvis Street's five lanes to four traffic lanes and two bicycle lanes between Charles Street and Queen Street East.

The project is slated to take three weeks and cost about $65,000.

"In order to undertake this work safely, a series of partial road closures and lane reductions will be required," the city of Toronto said in a news release.

The city was to spend Friday and Saturday removing pay-and-display parking machines and taking the centre reversible lane out of commission.

During the week of July 19, the city will begin pre-marking bicycle lanes and removing reversible lane hardware and signage.

On the weekend of July 24 and 25, the painting of lanes will result in rolling closures, the city warned. Those will be in effect from Bloor Street East south to Queen Street East.

Bicycle and diamond symbols will be installed in the bicycle lanes during the week of July 26 -- a move that will result in some localized curb closures.

The expansion of bicycle lanes has been politically controversial.

Mayoral candidate Rocco Rossi has stated his opposition to putting bicycle lanes on major arterial roads. He promised on Thursday to remove the Jarvis bicycle lanes if he is elected mayor and move them to Sherbourne Street.

Daniel Egan, Toronto's manager of pedestrian and cycling infrastructure, said the changes will leave Jarvis as a four-lane road "like every other street downtown."

Some current members of city council did oppose the project, which they consider a waste of money.

"Look at cities like Chicago, San Francisco and Montreal that have a similar climate," said Coun. Adrian Heaps. "Toronto is way behind in terms of commitment to installing bicycle lanes."

The city has added about 300 kilometres of bicycle lanes since 2001. The next street slated for bicycling lanes is Bay Street.

One cyclist told CTV Toronto to that in many European countries, bicycles come first.

Some drivers say there's too much traffic to reduce the number of lanes, although the project's advocates say making it easier to cycle will reduce the number of cars on the road.

With a report from CTV Toronto's Naomi Parness