Pink and Purple Line Express trains are being rerouted downtown due to track switching problems through Wednesday’s rush hour period.

Through 9 p.m., Pink and Purple Line trains will be rerouted via the Outer Loop — the Brown Line side — because of a track switching problem at Lake and Wells, according to a commuter alert from the transit agency.

Travelers should board all Pink and Purple Line trains on the Brown Line platform.

Brown, Green and Orange Line trains will all operate normally.