It's become a common annoyance at the newest light rail stations in Seattle -- a sign telling commuters an escalator is out-of-service.

An “up” escalator at the Capitol Hill stop was closed during the evening rush Monday. Commuters trying to use an escalator at the University of Washington station found a similar scene Tuesday. A nearby elevator was also out of service.

The Capitol Hill and UW stops opened last year, so why are they having these ongoing problems?

Kimberly Reason, a Sound Transit spokesperson, said escalators break down for a variety of reasons: It could be caused by weather, someone tampering with the machinery, or debris jammed in the moving parts.

A fix can take a full day or more depending on the job. Sound Transit says some repairs require an extra inspection by the Washington Department of Labor and Industries. That's something that has to be scheduled and can cause additional delays.

"Sound Transit is working with King County Metro and KONE (an elevator maintenance company) to examine what we can do to facilitate faster repairs,” Reason said Tuesday.

Some commuters wonder why an out-of-service escalator is blocked and cannot be used as a stairway. Sound Transit says it does this for safety reasons. Escalator steps, which are taller than normal stair steps, don’t match international building codes for stairways.