SAN FRANCISCO (KRON) — Drivers leaving the city will see an extra lane on the Golden Gate Bridge during their evening commutes starting Tuesday.

The Golden Gate Bridge, Highway & Transportation District is making a change to the regular evening commute lane configuration to help better balance traffic congestion across the bridge during those busy hours.

Commuters can now expect four northbound lanes and two southbound lanes from 4:00 p.m. to 6:00 p.m.

The current norm is three northbound lanes and three southbound lanes.

While four north/two south will be the new regular configuration, drivers should know there may be occasional unexpected changes to the configuration based on emergencies, accidents, or unusual traffic conditions. Those deviations from the regular pattern will be sent via Twitter notifications from @GGBridgeAlerts.

The bridge lanes will be configured in this way based on recent experience with growing Bay Area traffic, seasonal traffic patterns, and the completion of major roadwork involved with the Presidio Parkway project.

Bridge officials will monitor the bridge traffic and evaluate the effectiveness of these measures regularly.