"There are a lot of members out there who are just philosophically opposed to increasing the tax," Graves told reporters on Wednesday. "That's all there is to it."
Plus, he pointed out, the gas tax will bring in less revenue over the years as more drivers turn to fuel-efficient or alternatively fueled vehicles such as electric cars.
That's why Graves said he's "a believer" in implementing a fee on vehicle miles traveled, or VMT, as a long-term solution.
"We could implement it in the commercial sector almost immediately," he said. "In the commercial sector they're already logging in miles ... It might be a little farther away in the private sector, and that comes with acceptance and the technology."
He doesn't buy critics' arguments that such a tax would penalize drivers in rural areas.
"They're already driving farther so they already have to pay more gas tax than somebody who is driving, you know, two miles across town," Graves said. "Equity is already built into that argument so that doesn't necessarily worry me."
Graves' embrace of the tax on miles traveled separates him from the current chairman of the House Transportation Committee, Bill Shuster, R-Pa., who Wednesday called on President Donald Trump to back a gas tax increase.
"I, for one, think it's time to do it," said Shuster, who is retiring this year.
The U.S. Chamber of Commerce has proposed raising the gas tax by 25 cents per gallon, a plan the group says would raise $394 billion for infrastructure investments over the next decade.
Ed Mortimer, the chamber's executive director, said he's open to other alternatives, but said the federal government is far from being able to implement a tax on drivers based on miles traveled.