Environmental advocates in Pennsylvania want to see a faster switch to electric buses to help eliminate emissions that can worsen asthma and cause other health problems.
More than 23,000 diesel-powered transit and school buses exist throughout the state.
In the past, environmental groups have pushed to clean up diesel buses by taking steps like retrofitting the vehicles with filters to reduce pollution.
“At the time that solution made a lot of sense,” said Rachel Filippini, executive director of the Pittsburgh-based Group Against Smog and Pollution. “But now in 2018, we have a better solution that will reduce emissions even further, and that’s electric buses.