For the first time in a presidential election, Pennsylvania voters who run into registration or other problems at the polls on Tuesday will be able to cast provisional ballots right then instead of having to go to court.

Nobody knows how many there will be or if the number will be significant, said Mark Wolosik, manager of the elections division of Allegheny County.

In the April primary election, more than 2 million people in the state voted, and about 2,300 voters cast provisional ballots. The number could be much higher on Tuesday.

Voters whose names do not appear on the registers, who are at the wrong polling place or who are challenged by an election official will get provisional ballots.

In addition, first-time voters will have to cast provisional ballots if they do not have some form of identification, such as a driver's license, a passport, a bank statement or a utility bill with them when they vote.

Each voter will sign an affidavit on the back of the ballot and receive a ballot identification number so he or she can later call the county elections division to find out if the vote was counted.

Congress passed the Help America Vote Act in 2002 to remedy some of the problems that plagued the 2000 presidential election. The new federal law requires all 50 states to provide provisional ballots to voters whose eligibility is questioned by election officials.

In the days following the election, those officials will decide which votes should count.

Nathan Persily, an expert in election law at the University of Pennsylvania Law School, estimates that as many as 1 million provisional ballots will be cast across the country -- and that, he says, is a "conservative" estimate.

Public opinion polls have consistently placed President Bush and Sen. John F. Kerry in a tight race, both nationally and in swing states like Pennsylvania. So lawyers for both campaigns may target provisional ballots if the number of such votes exceeds a margin of victory for either Bush or Kerry, meaning Americans may wake up Nov. 3 and not know who won the election.

"In a close election, there's a greater possibility the parties will challenge votes," Secretary of the Commonwealth Pedro Cortes said.

A law signed earlier this year by Gov. Ed Rendell mandates an automatic recount if the margin of victory in a statewide Pennsylvania election is less than half of 1 percent of all votes cast. If 5 million votes are cast, for example, a victory of less than 25,000 votes would trigger a recount that includes the provisional ballots.

Allegheny County officials have been preparing for a surge in provisional ballots during the presidential election.

On Oct. 18, lawyers from both campaigns, the county solicitor's office and the four Common Pleas judges who will hear legal challenges on Election Day met with Joseph James, president judge of Allegheny County Common Pleas Court, at his courtroom in the Frick Building, Downtown.

James said he went over a four-page pamphlet that explains the ballots and will be given to election workers for use on Tuesday.

In past elections, James said, voters who were challenged at a polling precinct had to go to the seventh floor of the City County Building to get a court order allowing them to vote.

"The provisional ballot takes disputes out of the courtroom and leaves them to election officials" on the day of the election, he said.

But those disputes could end up in the courtroom anyway.

County election officials will start counting the provisional ballots three days after Tuesday's election, checking to see if each person who cast a ballot was a registered voter, Wolosik said. The amount of time it takes to count those votes will depend on how many are actually cast.

Lawyers representing the Republicans and the Democrats can challenge any votes; an appeal would first go before the county Board of Elections, then Common Pleas Court, Wolosik said.

Although no one knows how many provisional ballots will be used, local volunteers with Election Protection, a coalition group that is monitoring the election, plan on making sure election workers know how to use the new ballots and are actually using them.

"It's a new ball game," said Mark Willard, a lawyer at Eckert-Seamans, the Downtown firm that is organizing the Election Protection effort in Allegheny County. "We just want to make sure everyone does it right."

Willard said his firm's offices will serve as a "war room" for a group of 60 volunteers, including law students from Duquesne University and the University of Pittsburgh, who will target some of the county's more than 1,300 polling sites to see if voters are encountering difficulties.

"We're doing this as a pro bono effort for the community," he said.

But James does not expect serious problems on Election Day.

"I'm reasonably optimistic. There could be hundreds of thousands of these [provisional ballots]. But they're not chads," he said, referring to the problematic voting cards that hampered voting in Florida in 2000. "These are paper ballots. We should be able to read them."