Maryland county officials gathered in Annapolis expressed concern yesterday about Gov.-elect Robert L. Ehrlich Jr.'s plan to tap the state's transportation trust fund to help plug next year's $1.2 billion state budget shortfall.

Ehrlich's transition team won't say how much he might take from the fund, which is supported by revenue from the 23.5-cent-a-gallon state gasoline tax. But lawmakers are being told that the amount for next year alone will be at least $100 million. County leaders fear that could cause significant delays in proposed road and transit projects. Ehrlich has said he believes he can borrow money from the fund with only minimal disruption.

But until they see Ehrlich's budget, to be released Friday, county officials remain worried.

Montgomery County Executive Douglas M. Duncan's "Go Montgomery!" plan to ease traffic in the snarled Washington region, for instance, depends in part on state money. Ehrlich promised during the campaign to make traffic relief a focal point of his administration, and Duncan (D) raised concerns about that pledge yesterday at the annual meeting of the Maryland Association of Counties.

"I find the whole thing odd, because he ran on transportation, and then the first thing you do is start slashing the transportation trust fund?" Duncan, widely viewed as a possible rival to Ehrlich in 2006, said in an interview. "This is a step backward if he does it, and a major change from his campaign promises."

Ehrlich's administration does not plan to propose a gas tax increase this year to pay for transportation projects, but the incoming governor has left open the possibility that he might sign one. A 5-cent increase would raise $100 million to $150 million for the trust fund.

"We haven't made a final determination on a gas tax," said Ehrlich, who has publicly ruled out increases in the sales or income tax.

"The long-term remedy here is not a gas tax increase," he said. "It is in the identification of a new revenue source."

Duncan, speaking at the county conference, reiterated his own plan to lobby for a 10-cent increase in the gas tax as a way of financing his $9.5 billion, 10-year plan to improve Montgomery's roadways.

Rattling off a list of dire statistics -- in Montgomery, the third most-congested county in the nation, commuters spend an average of 84 hours a year in traffic jams -- Duncan warned that the situation would only get worse, predicting 14 hours of congestion on the Capital Beltway daily.

"When you talk about people pursuing their dreams, you can't do that if you're stuck in traffic," he said. "It doesn't relieve traffic congestion if you're not building new roads."

Duncan's ambitious plan would spend $1 billion of the county's money, splitting it almost evenly between road and public transit projects. He is also asking the state to spend about $8.5 billion on various road and transit projects, including construction of the Metro Purple Line and the intercounty connector linking Interstates 270 and 95. He also has pitched a $25 fee on autos registered in the county, which would raise $23 million for Montgomery.

Duncan commands strong support from the county's representatives in the General Assembly, even though the 10-cent increase would give Maryland the highest gas tax in the country.

"I agree with County Executive Duncan that unless we do something, we are going to have tremendous problems," said state Sen. Ida G. Ruben (D-Montgomery).

"The only alternative is that you put stop signs or gates at the border of this state saying, 'Don't come into this state,' " she joked.

Other local leaders worried more generally about the effect of the state's financial problems and said they hope they can hold on to the funding they already have.

Anne Arundel County Executive Janet S. Owens (D), for example, skipped her usual custom of showing a "wish list" to her assembly representatives, instead asking only for a level of funding necessary to run essentials.

"Quite frankly, I think that's going to be a real challenge," said Del. Mary Ann E. Love (D-Anne Arundel).