The 2009 inauguration was a landmark event for the capital region’s transportation system. Chances are that on Monday we’ll have a more typical experience with what is always an atypical day.

Attendance will be smaller than in 2009, but the transportation network still must deliver a crowd about equivalent to the D.C. population into a high security zone of a few square miles.

People planning to attend events wrote in to ask when I thought an outer Metro station’s parking might fill up, or what time they should reach the entry points for the inauguration parade route.

I bonded with forecasters trying to predict whether we’d get snow Thursday. It was impossible to make specific calls on timing and accumulations, whether talking about snow or people.

Last time

I can give you a personal view of what’s different.

While hundreds of thousands of people are expected to flock to the National Mall for President Obama’s second inauguration, the crowds will probably be thinner than four years ago. But how many people really attended Obama’s first inaugural? Watch this video to find out. (The Washington Post)

In 2009, I started Inaugu­ration Day at a commuter bus park-and-ride lot in southern Howard County. The first carload of inauguration-bound travelers pulled in at 3:45 a.m. I was planning to drive from there to the gigantic parking field at the Greenbelt Metro station when I heard the lot was full. It was 4:30 a.m.

By 5:45 a.m., Gallery Place station looked like it does at the height of rush hour, only friendlier, because people were in such a good mood. South of the Mall, the L’Enfant Plaza station was comparatively quiet, though that would change dramatically.

The highlight for me was joining the big crowd walking across the Arlington Memorial Bridge. Many people hung around the steps of the Lincoln Memorial. They thought it was a fine environment for experiencing a historic moment, or they just didn’t want to advance farther into the Mall crowd.

This time

I hope to visit many of the same spots Monday but expect differences to be obvious. There’s no need to visit the park and ride, because Maryland won’t be operating commuter buses. Greenbelt may fill up, but if so, it’s likely to occur later.

Because this is President Obama’s second inauguration, representing less of a historic change and drawing a smaller audience, I don’t expect to be part of a similar throng crossing the Arlington bridge. Anyone hanging back by the Lincoln Memorial till noon probably won’t have much claim to being part of inauguration 2013. You can barely see the Capitol dome.

What’s different?

One of the big questions in 2009 was: How do I get to work? I hear little of that this time, because the public ceremonies coincide with Martin Luther King Jr. Day, a federal holiday.

The road restrictions, still impressive, are somewhat diminished from 2009, especially in regard to the Potomac and Anacostia River bridges. Only the Arlington Memorial Bridge will be completely closed to motor vehicles.

While that might make some drivers breath easier, it complicates the traffic forecast. Barring Roosevelt Bridge traffic from Constitution Avenue and 14th Street Bridge traffic from 14th Street might have some unintended consequences.

What’s similar?

Although Metro probably will haul fewer people than in 2009, the transit plan is much the same. The most noticeable exception is that parking payments will be collected as they usually are on weekdays.

People do heed calls to leave cars at home, and instead rely on transit and walking. Metro tends to do well, but there have been service interruptions. Out-of-towners don’t know where they’re going, Metro platforms and mezzanines are temporarily overwhelmed, and people get sent in the wrong directions.

In all of our accounts over the years, patience and flexibility save the big day.

Dr. Gridlock also appears Thursday in Local Living. Comments and questions are welcome and may be used in a column, along with the writer’s name and home community. Write Dr. Gridlock at The Washington Post, 1150 15th St. NW, Washington, D.C. 20071 or e-mail