Drivers may need a little luck of the Irish to get around Montreal on this St. Patrick's Day weekend.

In addition to the now-standard weekend closures around the Turcot Interchange, significant amounts of construction are blocking the Nuns' Island side of the Champlain Bridge and Highway 15.

Benoit Chamontin of the Champlain Bridge consortium said officials knew that tens of thousands of people were expected to come downtown for the annual St. Patrick's Day parade on Sunday, but that this weekend's work was unavoidable.

"It can happen that sometimes we can avoid to work at the same time, and usually the co-ordinators try to avoid that. So most of the time people don't see that [major work is happening simultaneously]," said Chamontin.

Martin Girard of Transport Quebec said if work was skipped this weekend, work on the Turcot and the Champlain Bridge would face significant delays.

"The co-ordination as mentioned was done so the work has to be done this weekend to respect deadlines and after that other work needs to be done for both projects," Girard said.

Since the beginning of the month crews have been installing the steel beams that will support the road decks on Highway 15 south running through the Turcot Interchange.

Turcot Closure

As has become routine, the Ville-Marie Expressway (Route 136) will be closed in both directions from midnight Friday March 16 until 5 a.m. Monday March 19.

The ramp from the southbound Decarie Expressway (Highway 15) to downtown and to Highway 20 West will be closed at that time, as will the connection from Highway 20 East to downtown, and from downtown to Highway 20 West.

The access to Highway 20 West and downtown from Highway 15 North will be blocked at de la Verendrye St., although drivers heading north on Highway 15 will be able tot continue onto Decarie.

The Rose de Lima entrance ramp to Route 136 West will be closed earlier, at 10 p.m. Friday, and remain closed until Monday morning.

Angrignon sector

Highway 20 Westbound will be closed from the Turcot interchange until the entrance from Highway 138/Mercier Bridge from midnight Friday until 5 a.m. Monday.

The Pullman St. entrance to Highway 20 west will be closed at 10 p.m. Friday.

Drivers heading East will be forced off Highway 20 at Exit 62/1st Ave. as of midnight Friday March 16, and all eastbound lanes will be closed until the Angrignon Blvd. entrance.

The Mercier Bridge/Highway 138 connection to eastbound Highway 20 closes at 10 p.m. Friday and will remain closed until 5 a.m. Monday.

Nuns' Island

This weekend sees a new closure around Nuns' Island as crews block roads in order to demolish two structures that are no longer needed.

The No. 5 exit ramp that leads from Highway 10/Bonaventure Expressway to Nuns' Island and to the Champlain Bridge will close at 11 p.m. Friday March 16 and reopen at 5 a.m. Monday.

The 57N exit ramp from Highway 15 South to Nuns' Island will close at the same time.

Drivers heading to Nuns' Island from Montreal will only have one access point: Exit 57S from Highway 15 South.

Those coming from downtown will have to take exit 4 from the Bonaventure, take Highway 15 North until the Atwater Exit, then loop around and enter Highway 15 South.

In order to facilitate traffic Exit 61 on Highway 15 South will be closed from 10 p.m. Friday until 5 a.m. Monday.

Part of Nuns' Island Blvd. will also be closed this weekend.