As part of a massive upgrade, the CTA will purchase 425 new buses and modify 1,030 others, Mayor Rahm Emanuel and CTA President Forrest Claypool announced on Friday morning.

The overhaul is expected to cost $500 million, with $165 million going to a rebuild of 1,030 standard, 40-foot buses, and  $330 million going to the purchase of new ones.  The funds for the new purchases will come from CTA’s sales tax revenue, according to a statement.

“A world-class city needs world-class infrastructure, and this investment in our infrastructure will help millions of Chicagoans commute while creating hundreds of jobs throughout our city,” said Emanuel, who announced the purchase and overhaul work at the CTA Chicago Ave. Bus Garage.

The new plan calls for 325 new purchases of 40-foot buses and 100 articulated ones. The CTA had already planned to purchase 100 buses, bringing the total number of new buses to 525.