The train route between New York City and Chicago was once the apex of luxury travel: Passengers boarded after walking on a red carpet laid out on the platform and nibbled lobster Newburg on fine china in the dining car.

The nearly 1,000-mile route has been far less sumptuous in recent years. And as of last week, for the first time since the late 1800s, what was once considered the ultimate modern journey — a straight-shot between two great global cities — is no more.

The temporary suspension of the storied route is the result of repair work by Amtrak to a bridge and a tunnel that are part of the rail connection between Pennsylvania Station and upstate New York. From the end of May until Sept. 3, the Lake Shore Limited, the most famous of the New York-to-Chicago trains, will run only between Boston and Chicago. A second link, the Cardinal, which travels between New York and Chicago along a southern route, is also temporarily suspended because of the same repairs. It will only run from Washington to Chicago.

“We’d like to restore direct service as soon as possible,” Marc Magliari, a Chicago-based spokesman for Amtrak, said, “so New Yorkers can more easily enjoy better pizza.”