It's an issue we've covered extensively for the last month: complaints over the rise in car-tab fees. We've heard from drivers. We've heard from lawmakers. On Thursday, for the first time, we heard from the head of Sound Transit.

Sound Transit CEO Peter Rogoff spent Thursday afternoon in Olympia, answering questions from lawmakers. He spoke at a meeting of the House Transportation Committee - a meeting that was called specifically to address growing concerns over car-tab taxes.

"We are open and willing and happy to discuss with members if there's a way to alleviate concerns over the depreciation schedule," Rogoff said during the hearing.

A few hours later, KING 5 met with Rogoff in Seattle, to get answers to some of the questions taxpayers are asking.

"I was late for this interview because I drove from Olympia and traffic was as bad coming northbound as it was southbound in the afternoon," he said.

Rogoff said he points to that congestion when explaining why car-tab fees are going up and what taxes, put in place under Sound Transit Three, are paying for.

The $54 billion voter-approved transit package will fund expanded light rail, commuter rail, and bus connections within the Sound Transit District in King, Pierce, and Snohomish counties.

The Sound Transit District includes 51 cities, 40 percent of the state's population, and 97 percent of the state's road congestion, according to Sound Transit.

Rogoff said the numbers show mass transit improvements are desperately needed.

"Let's remember that congestion in this region has, basically, almost doubled in the last five years. It went up 95 percent in five years," said Rogoff.

Still, he understands why this year car-tab bills left drivers feeling sticker shock. He even expected it.

"It's always a jolt when you get the envelope at home; we get that," he said. "This is public transportation. It's a very public process, as it should be. We're dealing with taxpayer money."

The car-tab controversy has mainly centered around the depreciation schedule Sound Transit uses to calculate car-tab taxes. It's a formula that's based on vehicle MSRP, or Manufacturer's Suggested Retail Price, as opposed to a car's fair market value.

That's what has taxpayers and lawmakers calling the tax inflated and unfair.

"It's disappointing to voters, understandably, that they're not paying on precisely the right dollar amount that they actually paid for the car. We understand that. I think we would all be concerned by that," said Rogoff. "It's one of the reasons we're working with the legislature to see if there's a more reasonable schedule that we can adopt and still deliver the Sound Transit projects voters voted for."

Both Republicans and Democrats in Olympia have proposed legislation that seeks to reform Sound Transit and change the way ST3 car-tab taxes are calculated.

"My own Sound Transit board members would like a simpler solution," he said. "Quickly."

Here's the problem: changing the formula is no simple task.

"We've told lawmakers we are open to alternatives, but we have three constraints we have to work within," he said. "We can't do anything that endangers our revenue such that we can't deliver projects in Pierce, Snohomish, King counties. We also need to work within state law, and we also need to be sure not to threaten our credit rating and bond repayments by doing anything precipitous."

So, would any of the proposals introduced so far in Olympia make sense?

"We're analyzing each of them to see if they meet those three tests," said Rogoff. "It's not easy. We've got bond counsel working on it, attorneys working on it, actuaries working on it, to see if we can move to a depreciation schedule that's more understandable by the public."