Commuters ride a LRT-1 train. Construction on the extension of Metro Manila's oldest elevated railway started on May 7, 2019. George Calvelo, ABS CBN News

MANILA -- Construction on the LRT-1 extension from Pasay City to Cavite province began on Tuesday, 5 years after it was awarded to Light Rail Manila Corp, the Department of Transportation said.

The extension, spanning nearly 21 kilometers, will add 8 stations from Baclaran: Redemptorist, MIA, Asia World, Ninoy Aquino, Dr. Santos, Las Piñas, Zapote and Niog, the agency said.

Five stations from Baclaran will be operational by the end of 2021, the DOTr said.

Once completed, the extension will nearly double the LRT's daily ridership to 800,000 from 458,000. It will also reduce travel time from Cavite to Baclaran to 25 minutes from 1 hour and 10 minutes.

Light Rail Manila, a joint venture composed of Ayala Corp, Metro Pacific Light Rail Corp and Macquarie Infrastructure Holdings, will manage the LRT 1 for 32 years.