Heavy traffic congestion is expected in downtown Seoul this weekend, where police are bracing for a large-scale labor rally.

According to the Seoul Metropolitan Police Agency, some roads will be closed off to vehicles due to a so-called national workers’ convention, which will include outdoor rallies along Eulji-ro in Jongno District led by the Korean Confederation of Trade Unions.

The Federation of Korean Trade Unions will hold separate rallies along Jangchungdan-ro in Yeouido, Seoul. Other affiliated unions will hold gatherings in various parts of the city.

The police agency said drivers should expect lane closures on Sejong-daero, Jangchungdan-ro and Yeouido-daero, and that passenger vehicles will be allowed to use the central bus-only lanes from the Jongno 2-ga Intersection to Heunginjimun Intersection.

A total of 330 traffic officers will be dispatched around the National Assembly building and other march areas.

Authorities are urging people to use the subway to avoid delays.