LOS ANGELES (AP) — A new underground train that will speed passengers through downtown Los Angeles took a symbolic step forward Tuesday with a groundbreaking ceremony attended by shovel-wielding politicians and transportation officials.

The “regional connector,” as officials with the Los Angeles County Metropolitan Transportation Authority call the new line, is a missing piece in a growing subway and light rail network. By tying together three existing light rail lines, it will eliminate the two transfers that riders traveling from one side of downtown to the other now endure.