[This post has been updated]

Amtrak has added extra trains to its routes to help accommodate the hundreds of thousands of passengers expected this week.

Most of the additional cars will run on the two busiest travel days: the Wednesday before Thanksgiving and the Sunday after.

The Wednesday before Thanksgiving is the heaviest travel day on Amtrak’s calendar. Last year, a record 134,230 passengers rode Amtrak on that day, and over the entire holiday week the service logged a record 704,446 riders. Similar numbers are expected this Thanksgiving, railroad officials said.

Extra trains and cars with added capacity will be added to the Northeast Corridor as well as around Chicago, the Pacific Northwest and in California.

If you’re traveling from Washington to anywhere in the Northeast, make sure you have a reservation. All Amtrak trains in the Northeast will require reservations. A Thanksgiving holiday timetable is available online and in stations.

Amtrak offers a few tips for passengers looking to have an easier trip: Book tickets early (rather than showing up on the Wednesday before or the Sunday after the holiday), get to the station early, don’t bring more than two carry-on bags per person (which doesn’t include laptop bags, purses and briefcases) and have photo identification.

There could also be a heightened police presence at stations and on trains due to planned increases in security efforts. This would also include random baggage checks at some stations, so be prepared for that possibility.