Washington State Ferries is advising travelers to expect long ferry lines and heavy traffic throughout the holiday weekend.

Tuesday’s foggy weather prompted multiple late sailings on the Bainbridge Island-Seattle route. According to WSF, however, the worst is yet to come. Nearly 350,000 people are expected to ride a ferry from Wednesday, Nov. 21, to Sunday, Nov. 25.

Ferry officials are warning travelers to leave early and use technology to help with trip planning.

The ferry system expects the longest lines westbound Wednesday, Nov. 21, in the afternoon and evening and Thursday, Nov. 22, in the morning.

Eastbound traffic is expected to pick up Thursday afternoon and Friday, Nov. 23.

WSF suggests that people driving onto ferries arrive early, or to travel during off-peak times. Vehicle reservations for the Anacortes-San Juan Islands/Sidney, British Columbia and Port Townsend-Keystone routes also are recommended.

“Our WSF family’s goal is to get everyone to their destination safely,” said WSF head Amy Scarton. “While the lines are longer during holidays, once aboard, ferry travelers can enjoy one of the most scenic ways to get to their Thanksgiving dinner.”

Travelers can check the fall sailing schedule or call 888-808-7977 for best times to travel, as well as which routes run on modified schedules on the holiday. (Additional holiday sailings also are marked on schedule lists).

People can also follow the WSF Twitter account for automatic updates on travel conditions.

Ferry officials also note that changes at Colman Dock start after Thanksgiving weekend.

Starting Monday, Nov. 26, the entire north half of the Seattle ferry terminal will be under construction and closed to vehicles waiting for the ferry.

The toll plaza and the southern vehicle waiting lanes will remain open, but when the lanes are full, drivers will be directed to wait at the off-site overflow vehicle waiting area on Pier 48.

Motorists should plan to arrive at least 30 minutes before the scheduled sailing to accommodate the smaller dock.