Zachary Bergum oversees Hawaiʻi County’s network of public buses, most of which run on diesel. As he spoke with HPR over the phone, he pulled up a spreadsheet on fuel costs over the last twelve months.
In 2025, Hawaiʻi County paid about three dollars and change for a gallon of diesel. That cost held more or less steady through February 2026.
“But soon as the following month hit — in March — we did see a spike,” Bergum told HPR.
That month, Iran closed the Strait of Hormuz in response to military strikes by the U.S. and Israel. The strait is a critical passageway for oil exports from the Middle East — about 20% of the world’s oil supply flows through it.
When that supply was choked off, prices for oil products like gasoline and diesel shot up. By April, Hawaiʻi County was paying more than six dollars a gallon for diesel — double the cost compared to just two months earlier.
Under Bergum, Hawaiʻi County’s Mass Transit Agency has a healthy cushion in its fuel budget. But other transportation agencies across the state found themselves short on fuel funds.
Kauaʻi's Transportation Agency tapped into a pot of federal dollars to cover about $145,000 in unexpected fuel costs.
Honolulu’s Department of Transportation Services ended up over budget on diesel costs by about $2.4 million last fiscal year. DTS used city contingency funds and found savings elsewhere in its operations to fill that gap, but DTS director Roger Morton is bracing for an even bigger budget hole this year.
Fuel costs started to level off this summer, but recent military strikes in the strait have pushed oil prices up again. Morton told HPR that as of last week, DTS is paying more than five dollars per gallon for diesel.
“If the prices were to stay where they're at now, then we would be substantially over our budget by the end of the fiscal year,” Morton said.
The new fiscal year started this month and runs until next June, and DTS has about $18 million in its budget to spend on diesel over that period. Morton said he thinks it’s “inevitable” that DTS goes over budget on fuel this year — the question is by how much. In a worst-case scenario, Morton anticipates that DTS could end up paying $25 million for fuel this year.
“It's still pretty early in the fiscal year, so I think we all hope that the conflict will be resolved and that fuel will go down in price,” he said.
While higher fuel costs mostly bring headaches, there is one silver lining for public transportation agencies — more people are taking the bus. Kauaʻi, Oʻahu, and Hawaiʻi Island transit agencies all reported higher ridership numbers last year, which their leadership attributed in part to the sticker shock drivers are facing at gas pumps.
“People are paying a lot more for gasoline for their cars. So I think at this point, it's a good time for the public to consider, ‘Hey, let me try the bus,’” Morton said.
And at least for now, all three transit agencies also told HPR that they were not considering hiking fares or cutting routes as a strategy to deal with rising fuel costs.
