The Rock ‘n’ Roll San Diego Marathon is happening on the last weekend of May in Balboa Park and more than 30,000 runners are expected.

There are three races scheduled for this weekend that will impact roads across the city. See below for more details:

5K:

The first, a 5K, will be held at Balboa Park at 7 a.m. Saturday.

The start line is on Presidents Way and Park Boulevard, with the finish line at Balboa Drive. Road closures will be along Sixth Avenue between Kalmia Street and University Avenue.

Marathon & half marathon:

The half-marathon and marathon are being held simultaneously on Sunday at 6:15 a.m.

The start line is on Sixth Avenue and Quince Street at Balboa Park, with the finish line at Ash Street and Union Street. Traffic from Mission Bay Park to Fashion Valley and Friars Road to Golden Hill will be impacted.

Here is a list of some roads that will be closed on Sunday, May 31:

Most road closures will be happening from 5 a.m. until 3:30 p.m., but race organizers said roads will reopen once the last participant passes and course materials are removed.

San Diegans can expect delays and heavy traffic in the Mission Valley, downtown San Diego, Balboa Park and surrounding neighborhoods. Caltrans said the following freeways would be affected:

Freeways:

Northbound State Route 163 (SR-163) from A Street to Friars Road.

Southbound SR-163 from Interstate 5/Park Boulevard at A Street.

Connectors:

Northbound SR-163 to eastbound/westbound Interstate 8 (I-8).

Eastbound I-8 off ramp to northbound SR-163.

Westbound I-8 to northbound SR-163.

Northbound Interstate 5 (I-5) to northbound SR-163

Southbound I-5 to northbound SR-163.

Street closures:

Balboa Drive from Upas Street to Marston Point

Sixth Avenue from Kalmia Street to Redwood Street

Adams Avenue from E Mountain View Drive to 33rd Street

Friars Road from Napa Street to Colusa Street (westbound lanes)

B Street from 11th Street to Fifth Avenue

Sea World Drive from Friars Road to the I-5 southbound on ramp. (eastbound lanes)

Click here to see a full list of street closures.

Organizers have provided alternate routes based on your neighborhood. Find community information here.