Unless you're going to the Keg or A & W, don't expect to drive down Third Avenue on the north side of Lansdowne for the next two weeks.

Traffic promises to be blocked and snarled around Lorne Street between Second Avenue and the Red Bridge from Monday, July 16, to Friday, July 27.

Kristen Meersman, City capital projects manager, said Friday the road closures are to allow for the construction of a traffic roundabout at Third and Lorne as well as other road and landscaping improvements.

The City had hoped to keep Lorne open between Third Avenue and the Red Bridge, but there has been a problem with vehicles stopping on the CP railway tracks.

"We had a near miss this morning," Meersman said.

Drivers can still access Riverside Park via First Avenue to get to the east or Heritage House parking lots.

But Second Avenue is closed off, so drivers have to enter and exit the area via First.

Anyone trying to get to the Red Bridge can approach it from the east via Tenth Avenue to Lorne.

Access on Third Avenue north of Lansdowne is restricted to drivers trying to get to the A and W or Interior Savings Centre building before the train tracks, or to the Keg or another Lorne Street business.

"We're trying to prevent through traffic," she said.

There will be traffic control measures in place.

This is expected to be the biggest closure of the Lorne Street construction project. Meersman said there could be some smaller closures in August and September.

Adding to the congestion are the Watchtower conventions being held this weekend and next at the Interior Savings Centre. The gatherings are expected to draw 4,000 people each weekend.