Ground will be broken Saturday on a project to extend metro Phoenix’s light rail system by three miles.

The new section of line will be built on 19th Avenue in Phoenix from Montebello Avenue northward to Dunlap Avenue.

Construction will begin Monday.

The $300 million project is slated to be completed in late 2015 or early 2016.

The first 20-miles of light rail opened in December 2008.

Six light rail extensions are under way that will create a 57-mile system by 2032.