It's been two decades since the Island Explorer bus picked up its first passenger on Mount Desert Island.
"We thought we'd be doing pretty well if we carried a thousand passengers a day, now there's never a day when we carried only a thousand passengers. Last year we carried 624,000 passengers," Downeast Transportation Executive Director Paul Murphy said.
Since it's inception, the Island Explorer has carried almost eight million passengers, reducing regular car traffic by almost three million cars.
And according to the park officials, that translates to a prevention of an estimated 41 tons of smog pollutants and 27,000 tons of greenhouse gases.
Now with the season of heavy traffic upon us, Murphy said the congestion could have been worse.
"Each bus carries 45 passengers or 43 passengers seating or standing. If you figure two point five passengers per car, it gives you an idea of how much worse the congestion would be in peak time is island explorer were not on the road," Murphy said.
On June 23rd the bus system will be getting 21 new propane buses to replace some of their older ones.
"They've been using propane fuel buses for almost twenty years, these buses are brand new, the technology is brand new, the style of the bus is brand new, created expressly for Acadia National Park," Propane Education and Research Council CEO Tucker Perkins said.
And after twenty years of providing park visitors for transportation throughout the island, park officials hope the Island Explorer will be here for another twenty years.