Beginning in December, Metro trains in the Washington metropolitan area will return to self-driving after a 15-year hiatus due to a deadly collision on the Red Line that killed nine people. 

Automatic train operation is actually found to be safer and more efficient than manually operated trains as it isn’t prone to human errors of missing platforms and sudden jolts of accelerations or slowdowns. Trains will also face fewer delays as they will be able to run at their maximum allowed speed. The agency says once fully automated, trains will be running faster at an average of 4 mph.