I stood, frozen in place, on the sidewalk at the intersection of who-knows-where and what-am-I-doing-here, desperately trying to orient myself with my cellphone and dodging pedestrians who actually seemed to know where they were going.

The minutes were ticking past. All I needed to do was find one bus stop, but somewhere between my hotel, a block back in Center City Philadelphia, and this corner, I’d lost all sense of direction.

I looked at the schedule on my phone. The bus that would have taken me to Woodford Mansion, a historic home in the city’s vast Fairmount Park, had come and gone. The next one wasn’t far behind, but it would drop me off just 15 minutes before the house closed at 4 p.m. Provided I could find the stop.

I called the mansion to see whether I could slip in for the last tour if I succeeded. The woman who answered said that I’d really need about 45 minutes for a proper visit.

Translation: No.

If this was a sign of things to come, how was I going to tour Philadelphia entirely by public transportation?

I’m a big fan of short road trips. No exorbitant airfares, no relying on someone else’s schedule. Just get in the car and go. These days, though, nobody wants to pay $4 a gallon for gas. So I’d challenged myself to visit a major tourist city and get around only by public means.

This should have been a snap. After all, I’m a mass-transit junkie. My belief in getting around the way the locals do has put me on trolleys in San Francisco, buses in Chicago, commuter rail in Connecticut and subways in New York.

So I had high hopes for my ability to navigate on the Southeastern Pennsylvania Transportation Authority, Philadelphia’s public transit system. Before leaving Washington, I gave the system map, a hodge-podge of subways, regional rail, trolleys and buses, just a cursory once-over. I had a list of places to see, and SEPTA seemed so comprehensive, I figured that no matter where I wanted to go, I’d have no problem getting there.

Things started off fine. I snagged a round-trip ticket on Megabus for $30, half as much as I’d recently paid to fill up my 1997 Mercury Sable, and we left Washington only about 10 minutes late.

The problem began at Philadelphia’s 30th Street Station. Since we were on time, I decided to catch a local bus out to Valley Forge, about 25 miles from downtown. But first I needed lunch. It just happened to be free-cone day at Ben & Jerry’s, so I queued up at the train station kiosk.

I wasn’t too concerned when I saw that I’d missed the 1:42 p.m. bus to Valley Forge. There was another one in half an hour, and the visitor center at the park didn’t close until 5. I figured that even after an hour-long bus ride, I’d still have almost two hours there, plus time to wander the grounds, which stayed open until dark.

But then, sitting at the bus stop, I started to scour the schedule. Oops. The last bus from Valley Forge left at 4:50 p.m., meaning that I’d have less than two hours to see everything. And the thought of hauling around my heavy backpack while touring was beginning to weigh me down as much as that ice cream cone I’d just consumed.

Change of plans: I’d check into my hotel, dump the backpack and be on my merry way to Woodford.

After a few minutes consulting the map on my phone, I dashed out of the hotel. And that’s how I found myself confused, alone and in every sense at a crossroads.

Having now eliminated two of the possibilities on my list, I made a snap decision to visit the Philadelphia Navy Yard. I headed for SEPTA, where I pulled out the Independence Pass (unlimited travel for $11 per day) that I’d bought at 30th Street Station and tried swiping it at the fare gate. Nothing happened. I dragged it through the reader a couple more times before an employee called me over and said that I needed to show the pass to a worker every time I entered a station. Visitors beware: I’d been duped by the magnetic-looking-but-not-magnetic black stripe on the back of the card. The only way to make it through a subway turnstile is to have a worker send the signal to let you in.

“Hello, I’m a tourist,” I joked. The worker didn’t laugh.

He took my pass and punched the month — March. Except the date was April 3. He handed it back with a vague sort-of apology. The rest of the day, I was sure that my guilty conscience was showing as I flashed the mispunched pass at transit employees.

The train deposited me at the last station on the Broad Street Line. From there, I got on the SEPTA bus to the Navy Yard, which was a pleasant enough place but not quite what I’d expected. Mostly it’s a research and office park, lined with some historic buildings. That Urban Outfitters I’d spotted on Google Maps? That would be the company headquarters, not a store. I had a nice walk down to the waterfront before locating a stop to get on the bus to the subway.

My next destination was the one that is most people’s first: Independence Hall. Getting there involved a transfer at City Hall Station. This time I got the full public transportation experience. It was shortly after 5 p.m., and workers poured onto the subway platforms and into the train cars. I barely made it off at Fifth Street Station. Just like home.

At the national park, I snapped pictures of the Liberty Bell behind a plot of tulips and took a leisurely stroll on my way to Second Street Station. From there, I headed to the happening Northern Liberties neighborhood for dinner.

On the train back downtown afterward, I was feeling tired from my day of mass-transit touring and had to urge myself to stay alert.

Good thing I was paying attention: The automated station announcements were out of sync, lagging one behind where we actually were.

In my hotel room, I plotted my moves for the next day, downloading schedules to my phone, noting bus stop locations and studying the Center City map. I vowed to know what I was doing.

The morning nearly got off to a bad start. According to the schedule, the 125 bus to Valley Forge left from 13th and Market streets. I got there plenty early. Seeing a few large bus shelters, I felt confident that I was in the right place, even though there were no signs listing the routes.

Then the bus drove past me on the street perpendicular to the one I was on. I ran around the corner to chase it down, but the driver waved me away. It was time for his break. Of course.

Only as I was catching my breath did I see the sign for the bus stop and a line of waiting riders. How an out-of-towner is supposed to know to go nearly a block past where the listed stop is, I don’t know.

The bus left about 10 minutes behind schedule. We spent a good bit of time circling through the massive King of Prussia Mall, as I’m sure George Washington did en route to the encampment in 1777.

In the Valley Forge National Historical Park visitor center, the volunteers at the information desk were apologetic, because without a car, there wasn’t much that I could do, especially in the off-season. The trolley tour was operating only on weekends. The nearby bike rentals also were not available on weekdays.

I browsed through the exhibits, watched an 18-minute film and set out for a walk. Passing reconstructed huts, I made it as far as the National Memorial Arch before hoofing it back to the visitor center so as not to miss the bus.

It was a long, slow ride to the stop outside Center City where I’d transfer to another line to finally get to Woodford Mansion. We arrived late, so I missed the bus I’d pinpointed the night before. I thought I was going to miss the next one as well, but it was behind schedule, too.

My solo tour of the circa-1756 mansion took about 45 minutes. Then it was back to the bus on a line paralleling the Broad Street subway.

A few blocks east of Broad, I found the Ninth Street Italian Market, where I wanted to visit Fante’s Kitchen Shop. Its dizzying array of merchandise nearly seduced me into a shopping frenzy, but I reminded myself that I’d have to lug around anything I bought on subway and bus rides. Right. Pearl sugar and candied orange peel will do, thanks.

Even with the impulse purchase, I felt pretty flush with cash. Between the Megabus fare and SEPTA passes, my transportation costs amounted to $52. Based on my car’s miles-per-gallon highway rating and the $4.14 price of gas near my house, I probably would have gone through something like $45 worth of fuel just getting to and from Philly. Never mind city driving, idling in traffic and parking fees.

My ad­ven­ture at an end, I picked up my backpack at the hotel and set off for the train station, hoping that I’d encounter my old friend the 125 bus pulling into one of the stops along the way. No such luck.

I walked the final mile.


Tips for vacations using public transportation

One-tank trip from D.C. to West Virginia