ST. PAUL (AP) -- The Twin Cities' Metro Transit is advancing efforts to one day have all of its buses powered by electricity.

Labor unions, environmental and transit advocacy groups are supporting the plan to buy more electric buses in the next few years. The goal is phasing out diesel buses entirely.

The public transportation service wants to install shields on 150 buses to combat recent assaults on its drivers.

Metro Transit Deputy Chief Brian Funk says the clear acrylic armor that can be opened or closed at the driver's discretion. That option helps drivers protect themselves without compromising their customer service.

Metro Transit struck a $12.5 million deal in July with a transit bus manufacturer to build battery-powered buses and related charging equipment for the C Line.