MINNEAPOLIS (WCCO) — Thousands of runners laced up their shoes Sunday morning for the 31st Medtronic Twin Cities Marathon.

The 26.2-mile race started at 8 a.m. It took runners from the Metrodome in downtown Minneapolis, around the Chain of Lakes, and ended at the capitol in St. Paul.

In addition to the 12,000 participants, organizers expected some 300,000 spectators.

That means drivers will have a tough time navigating traffic near the course.

Barricades are up in Minneapolis near the lakes, Minnehaha Parkway and West River Road.

And, in St. Paul, East River Road, Summit Avenue and John Ireland Boulevard are closed to drivers until 2 p.m.