Metro Transit is indefinitely suspending trips along dozens of bus routes beginning Tuesday, citing a growing shortage of bus drivers.

The state's largest bus operator announced the cancellations in a news release posted on its website Monday night. More than 65 trips spread between 40 bus routes across the metro area will be suspended.

Metro Transit is about 90 drivers short of its target workforce, "which has made it harder to cover all scheduled trips, despite tremendous daily efforts to do so," according to the release. The agency added that it is conducting an "aggressive campaign" to hire more drivers.

Despite the short notice, Metro Transit said it hoped the announcement would give riders enough time to make other travel arrangements.

Some routes will have multiple suspensions. Route 3, which runs between downtown Minneapolis and downtown St. Paul, will have six fewer trips. Route 270, an express bus from Minneapolis to Mahtomedi, will have four fewer trips. Route 18, which runs from downtown Minneapolis to Bloomington, will have three fewer morning trips.

Online schedules and Metro Transit's NexTrip service were already updated to reflect the changes. Unexpected cancellations will also be reported through e-mail and text notifications.

View the full list of trip cancellations at bit.ly/2vpI9bI.

The suspended trips make up about 1 percent of all scheduled weekday trips, according to the transit agency. Announcing the changes now, according to the news release, will help reduce the number of trips canceled at the last minute.

More changes are expected to take place on Aug. 18.

Metro Transit's employment woes were documented earlier this summer. The agency had about 1,500 bus drivers but was 57 short of its preferred number.

Suburban bus services, such as SouthWest Transit, were also having difficulty hiring enough drivers at that time.

Trips were also abruptly canceled through e-mail and phone alerts in late 2017, when Metro Transit said it needed 30 to 40 more drivers to complete its routes. At the time, the operator was recruiting for employees at public events and asking drivers to take on extra shifts.

Miguel Otárola • 612-673-4753