Pittsburgh’s buses have already had a pretty exciting week. One was eaten by a giant sinkhole Downtown and inadvertently became a social media star.

Quite possibly the funniest tweet we saw yesterday about the sinkhole came from photographer Dave DiCello. Screenshot via Twitter.

Now, the current bus fleet is getting some company (and hopefully, staying above ground). The Port Authority of Allegheny County is putting the first of 59 new “clean diesel” buses on the road as part of a regular program to replace its aging fleet with more efficient models.

The 40-foot American-made Gillig buses are winding their way 2,600 miles to Pittsburgh from their origin at a factory near San Francisco. Before the end of the year, all should be in Pittsburgh, where they will undergo state inspection.

“It’s really important for us to use the buses that we have, and make sure that we use taxpayer money as efficiently as possible,” says Port Authority spokesman Adam Brandolph. “Our buses are driven about a half a million miles or 12 years. Usually, it’s 12 years.”

Here’s a bonus: Though the buses will look the same, riders on the new models can charge their phones or laptops as they ride. Each new bus will feature USB ports.

The “clean diesel” buses will also emit less pollution than current models.

“Essentially, these are diesel buses with diesel particle filters, which remove particulate matter from the exhaust,” explains Brandolph. “It’s a filter that goes before the exhaust. Those filters are later pulled from each bus, and are baked in a kiln and cleaned off, so the filter can go back in.”

As the technology becomes better every year, Brandolph tells us “the buses become cleaner every year. Just like last year, these are the cleanest buses that we’ve ever put on the road.”

Passengers can easily charge their phones at their seats on the new Port Authority diesel buses. Photo courtesy of Port Authority.

Each bus costs $473,000, paid for through $22 million federal, $5.5 million state and $180,000 county funding.

The city is also expecting delivery of two battery-powered electric buses later this year, which will be an even more environmentally-friendly mode of transportation.