WASHINGTON (AP) — A major service adjustment for Metrorail is about to take effect.

Metro’s “Rush Plus” service starts during the Monday morning rush hour and will affect about 110,000 riders on the green, yellow, blue and orange lines.

Metro officials tell WTOP-FM they expect some confusion on the first day, despite an “extensive campaign” to educate readers about the changes. Spokesman Dan Stessel says customers need to pay close attention to the destinations of the trains they’re boarding.

Among the changes: Some yellow line trains will now start at Franconia-Springfield and end at Greenbelt during rush hours. The idea is to provide quicker access to downtown Washington from northern Virginia.

Metro says 21 stations will see an increase in the number of trains during the morning and afternoon rush hours.

(Copyright 2012 by The Associated Press. All Rights Reserved.)