01/24/2012 01:46 pm ET Updated Jan 24, 2012

10-Car Red Line Train Makes Full Shady Grove-Glenmont Run

WASHINGTON -- Three Metro personnel have been disciplined after a Dec. 2 incident where a Red Line train left the Shady Grove terminal with 10 rail cars -- two cars too many to fit on station platforms.

As the Examiner reports, while such incidents are usually noticed a few stations into a train's service run, the extra-long train went all the way to Glenmont.

There were no passengers in the extra rail cars.

This is not the first time Metro has mistakenly run extra-long trains. In one incident on the Green Line, a Metro employee involved in a 10-car train incident tested positive for drugs and was sent to rehabilitation.

As a safety measure in 2009, Metro mandated that all its train cars -- regardless of length -- pull to the front end of station platforms, eliminating the risk of eight-car trains from stopping short on platforms, which forces rear rail cars to remain in the tunnel while the rest open to the platform.

Metro typically runs six- and eight-car trains for rail service.