At noon on January 20, 2009, in a ceremony looking westward from the steps of the Capitol building in Washington over the National Mall, Barack Obama is due to be sworn in as the 44th President of the United States.

Record numbers are expected to pack the Mall, a 700-acre national park in the heart of Washington affectionately called "America's front yard", to watch Obama take the oath of office and deliver his inaugural speech.

The US President has been sworn in on the steps of the Capitol's western facade since 1981.

That year, Ronald Reagan asked to take the oath of office on the west-facing side of the legislative building as opposed to the eastern facade, where the inauguration had been held since Andrew Jackson's swearing-in in 1829.

Reagan wanted to face towards the state of California where he was governor before his election to the presidency.

The next three Presidents, George H W Bush, Bill Clinton and George W Bush, continued the tradition started by Reagan, not because they wanted to pay tribute to California but because the Capitol's western facade looks out over the National Mall, which can hold massive crowds.

The Washington Metro carried some 811,000 passengers on the day of Clinton's first inauguration in 1993, and 6,02,000 for George W Bush's first swearing-in in 2001, according to data it provided.

"We expect the crowds (for Obama's inauguration) to be huge with hundreds of thousands of people expected to be in the nation's capital not only for inauguration day but for the days preceding it as well," the general manager of the Washington Metro, John Catoe, said this week.