Tens of thousands of runners will take to the streets of Ottawa (and Gatineau) this weekend in six races as part of the Tamarack Ottawa Race Weekend.

Each race on Saturday and Sunday begins at the corner of Elgin Street and Laurier Avenue, outside Ottawa City Hall, and ends at the Cartier Drill Hall along the Queen Elizabeth Driveway.

Complete Ottawa Race Weekend information

Race weekend also means road closures — lots of them — and presents challenges to commuters and people attending other events.

Some roads closed all weekend

Queen Elizabeth Driveway between Laurier Avenue and Somerset will be closed from 8:00 a.m. Friday to 6:00 p.m. Sunday.

This includes the Laurier Avenue East off\-ramp and the controlled exit and access to National Arts Centre.

Specific exit and entrance requirements to and from Lawrence Freiman Drive post-performance and delivery via the Laurier Avenue off-ramp have been negotiated between ORW and the National Arts Centre.

The NAC says its underground parking garage is open both days, but public garage and parking spaces are filled on a first-come, first-served basis.

What about bus routes?

OC Transpo has a complete list of all bus stops that won't be in service during the weekend. Check their website for more details.

​What's happening on Saturday?

There are three shorter races running Saturday afternoon. A 2K race beginning at 3 p.m., a 5K race at 4 p.m. and a 10K race starting at 6:30 p.m.

The race weekend is not the only major event happening.

Earlier in the day traffic could also be a problem downtown and in the Glebe because of the Great Glebe Garage Sale, which runs from 8 a.m. to 3 p.m.

Regular parking rules will be enforced in the Glebe and to ensure emergency routes stay clear, the following streets will be marked as tow-away zones/parking prohibited even for permit holders: Fifth Avenue (from Bank to O'Connor), Bronson, O'Connor, Strathcona and Metcalfe.

What roads are closed on Saturday?

A look at the road closures on Saturday at their height at 4:15 p.m. (Tamarack Ottawa Race Weekend)

Here's a full list of Saturday's road closures. The road closures reach their height at about 4 p.m.

Laurier Avenue between Metcalfe and Nicholas: 1:00–9:00 p.m.

Elgin Street between Cooper and Wellington: 1:00–7:30 p.m.

Elgin Street between Cooper and Frank: 2:30-3:30 p.m.

Elgin Street between Catherine and QED: 3:30-8:45 p.m.

Lisgar Street between Cartier and Elgin: 3:30-4:30 p.m.

Elgin Street between Lisgar and Catherine: 6:15-7:00 p.m.

Frank Street between Elgin and QED: 2:45-3:45 p.m.

Queen Street between Elgin and O'Connor: 3:30-4:30 p.m.

O'Connor between Wellington & Albert: 3:30–4:35 p.m.

Wellington between Bank and Colonel By Drive eastbound: 3:30-5:00 p.m.

Lakeside: 6:00-8:00 p.m.

Bronson southbound between Lakeside and Colonel By: 6:00-8:00 p.m. (lane reductions)

Colonel By Drive between Rideau & Main: 3:00-6:15 p.m.

Colonel By Drive between Main and Hawthorne: 3:00-8:30 p.m.

Colonel By Drive between Hawthorne and Bronson: 3:00-8:30 p.m.

Pretoria Bridge: 3:30–8:45 p.m.

Argyle between and Elgin and Queen Elizabeth Drive: 6:30-8:45 p.m.

Queen Elizabeth Drive between Somerset & Elgin: 2:00–9:00 p.m.

Queen Elizabeth Drive between Elgin and Preston: 3:00-8:30 p.m.

The Ottawa Race Weekend site also has a map with an hour-by-hour breakdown of road closures.

What's happening Sunday?

Sunday is the day of the big races, beginning in the early morning at 7 a.m. with the Scotiabank Ottawa Marathon. That's followed an hour later by the Kids Marathon for CHEO. The half-marathon begins at 9 a.m.

Most of the road closures related to the runs are expected to be over by 2:15 p.m.

What roads are closed Sunday?

A look at Sunday morning road closures for the Ottawa Race Weekend at 9 a.m. (Tamarack Ottawa Race Weekend) Here's a full list of Sunday's road closures. The road closures extend far out along the marathon route from about 6 a.m. until 2:15 p.m.

Laurier Avenue between Elgin and Metcalfe: 5:00–10 a.m.

Laurier Avenue between Nicholas and Elgin: 5:00 a.m.–3:00 p.m.

Queen Elizabeth Drive between Preston & Elgin: 6:00-10:45 am.

Queen Elizabeth Drive between Lawrence Frieman & Laurier: 5:00 am-6:00 p.m.

Queen Elizabeth Drive between Elgin and Somerset W.: 6:00 a.m.-2:30 p.m.

Elgin Street between Cooper and Slater: 5:00–10:30 a.m.

Elgin Street between Cooper and Catherine: 8:45-9:45 a.m.

Lisgar Street between Cartier & Elgin: 6:00-8:30 a.m.

Cooper Street between Cartier and Somerset W: 7:45-8:30 a.m.

The Driveway between Cooper and Somerset W: 7:45-8:30 a.m.

Wellington Street eastbound between Elgin and Colonel By: 6:30 a.m.–2:00 p.m.

Rideau westbound between Sussex and Mackenzie: 7:30 a.m.-2:00 p.m.

Preston between Q.E. Driveway & Carling: 6:30-10:45 a.m. (northbound lanes)

Carling westbound between Preston & Sherwood: 6:45-11:00 a.m.

Carling eastbound at Preston: 6:45-11:00 a.m.

Sherwood Dr between Carling & Fairmont: 6:15–11:15 a.m.

Fairmont Avenue between Sherwood & Wellington: 6:15-11:30 a.m.

Wellington St. between Fairmont & Island Park Drive: 6:15-11:45 a.m.

Richmond Road between Island Park and Athlone: 6:15–9:30 a.m.

Athlone between Richmond and Scott: 6:15-9:30 a.m.

Sir Frederic Banting and Colombine: 6:30 a.m.–12:00 p.m.

Scott eastbound between Churchill & Island Park: 6:15–10:00 a.m.

Scott westbound between Island Park and Parkdale: 6:15 a.m.–12:00 p.m.

Island Park between Scott and Richmond: 8:15-11:45 a.m.

Sir John A Macdonald Parkway/Wellington between Booth and Island Park: 6:15 am– 12:15 p.m.

Booth Street between Wellington and Eddy Street: 6:45 am–12:45 p.m.

Eddy Street between Booth and Wright: 7:00–1:00 p.m.

Alexandre Tache between Eddy and Montcalm: 7:00–12:45 p.m.

Alexandre Tache between Montcalm and Scott: 7:00–10:45 a.m.

Scott between Alexandre Tache and Graham: 7:00–11:00 a.m.

Lac des Fees between Graham and St. Jean Bosco: 7:00–11:00 a.m.

Jean Bosco between Lac des Fees and Lois: 7:00-11:15 a.m.

Lois between St. Jean Bosco and Montcalm: 7:00-11:30 a.m.

Montcalm between St. Joseph and Papineau: 7:00-11:30 a.m. (southbound lanes only)

Montcalm between Papineau and Wellington: 7:00-11:30 a.m.

Montcalm between Wellington & Tache: 7:00 a.m.–12:45 p.m.

Wellington between Montcalm and Laval: 7:00 a.m.-12:45 p.m.

Laval between Promenade du Portage and Wellington: 7:00 a.m.-12:45 p.m.

Promenade du Portage between Laval and Hotel de Ville: 7:00 a.m.-12:45 p.m.

Hotel de Ville between Promenade du Portage and Laurier: 7:00 a.m.–12:45 p.m.

Laurier between Hotel de Ville and des Allumettieres: 7:00 a.m.–1:15 p.m.

Sussex Drive between York and Rockliffe Parkway: 6:00 a.m.–1:30 p.m.

Sussex Drive between York and Rideau: 7:00 a.m.-1:45 p.m.

MacKenzie Avenue between St. Patrick & Rideau: 7:00 a.m.-1:30 p.m.

George Etienne Cartier Parkway between Princess and Aviation Parkway: 6:45 a.m.–1:30 p.m.

Princess Street between Sussex & Lisgar Road: 6:45 a.m.–1:30 p.m.

Lisgar Road between Buena Vista and Rockliffe Parkway: 6:45 a.m.–12:15 p.m.

Birch between Sandridge and Hemlock: 6:45 a.m.-12:45 p.m.

Hemlock westbound between Birch and Beechwood: 6:45 a.m.–1:00 p.m.

Beechwood westbound between Lansdowne and Acacia: 6:45 a.m.-1:00 p.m.

Beechwood one lane westbound between Acacia and Crichton: 6:45 a.m.-1:15 p.m.

Crichton northbound between Beechwood and Dufferin: 6:45 a.m.–1:15 p.m.

Dufferin between Stanley and Crichton: 6:45 a.m.–1:15 p.m.

Stanley between Dufferin and Sussex: 6:45 a.m.–1:30 p.m.

Colonel By Drive – Rideau to Hawthorne Ave.: 6:00 a.m.-2:00 p.m.

Pretoria Bridge: 6:30 a.m.–2:00 p.m.

The Ottawa Race Weekend site also has a map with an hour-by-hour breakdown of road closures for Sunday.