WASHINGTON (AP) — Metro plans to have extra personnel available for the morning commute after a software program for tracking trains crashed twice over the weekend.

The supervisory staff will be available to deal with any problems Monday.

Hundreds of passengers were stranded and dozens of trains were forced to idle for about a half hour due to glitches early Sunday and Saturday afternoon.

Metro spokesman Dan Stessel says the computer issue affected Metro’s ability to see where trains were on the lines. He says trains in motion continued to their next stations, then sat with the doors open until the problem was resolved.

Stessel says the shutdowns were ordered out of “an abundance of caution.” He added that the signal system, which ensures that trains maintain enough space between them, remained operational.

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