Although we normally think of Ford/GM killing the electric trolley, my father (who came from a vaguely rail background), remembered with bitterness the city official he met bragging about his part in removing an inter-city tram service – (rail systems are run by robber barons and real-estate speculators). There used to be an inter-city trolley service running past my fathers home in Michigan.
Interurbans were rural streetcars that ran through the countryside, with a potential stop every couple of miles. The dot-coms of the 1900s, lots of lines were built that almost immediately went into receivership.
But because most of them used standard gauge track and 600v DC current, it was possible for one interurban’s equipment to run on the tracks of another company. In 1910, a group from upstate New York set off on “the longest charter,” from Utica, NY through Buffalo, Cleveland, Detroit, Fort Wayne, Indianapolis, Dayton and Columbus, covering about 2,000 miles over the tracks of 28 different interurbans.
Seat61, the incredible resource for those of us who like to travel by train in whatever part of the world we’re visiting, includes instructions for some really lengthy journeys, such as London via Moscow and Beijing to Saigon. You could, I suppose, start somewhere in Scotland to go even further. You could also continue via Bangkok and down the Malay Peninsula almost to Singapore—except that the link from Saigon via Phnom Penh to Bangkok is a bus at the moment.
Great thread; I’ve been enjoying it.
A bit of terminology for the OP:
At least in the USA, the term “public transportation” usually means government owed and operated local services that are almost always priced far below breakeven revenue and are subsidized by general tax revenues. City, county, or regional bus and light rail services are the classic examples.
The term for commercial businesses that provide transportation at a hoped-for realistic price is “common carrier”. Airlines, intercity bus companies, cargo & passenger ships, and many railways around the world are examples of “common carriers”.
The US Amtrak and some countries’ airlines and railways are semi-government owned or semi-government subsidized in addition to being quasi-commercial. Those would still generally be called a “common carrier” rather than “public transportation”.
A pretty cool new tool is Transitland and its map of nearly all local transit routes in North America. By mousing over the routes, you can easily see if they’re classic “local” bus routes or intercity (Greyhound, Peter Pan, Megabus, etc.) routes.
From some previous discussions on transit geek forums, I knew of some of the places to look:
One surprise is that Oregon and Washington’s county bus systems link end-to-end all up the coast. So with an iron bottom and copper bladder, you could conceivably ride local buses from Crescent City, Calif., north along the Oregon and Washington coasts, then through Olympia, Tacoma, Seattle, and Bellingham to the Canadian border. That’s some 600 miles.
In Northern California, you can ride from Fort Bragg via San Francisco, San Jose, Salinas, San Luis Obispo, to Los Olivos. I get around 500 miles for that.
Santa Barbara to Barstow, some 200 miles. Looks like there’s no longer a local bus through Fort Pendleton, so Santa Barbara to the Mexican border (around 250 miles) can no longer be done without using Amtrak or Greyhound.
In South Florida, looks like you can go from Belle Glade (on Lake Okeechobee) to Key West. That’s over 250 miles.
If you’re looking for the longest (rail) mass transit single-ride route operated by a single authority, Wiki says it’s currently Belgium’s Coast Tram, at 42 miles length. In a couple of years, when L.A.'s Regional Connector project comes online, L.A.'s A-Line will become the world’s longest, running from Long Beach to Glendora over 49 miles, with further extensions still to come.
That’s not that bad all things considered.
Yeah, that’s 131 Euros per day. It’s a container ship, so I expect entertainment offerings are slim, which would mean you’re basically paying for a hotel room and some meals. They don’t mention anything at all about the accommodations/amenities. Presumably you eat the same food as the rest of the crew? Do you get your own cabin/bathroom, or would you be sharing with others?
I’m wondering what would be the lowest-skilled job on this ship, and how much the training would cost before I could do this trip and get paid for it…
Hotel, meals and transport.
It’s a really good deal.
Probably boring AF though.
Maybe not a bad retirement plan though. 
While looking through the Holland America Cruises website a few years ago, I found a 108 day cruise. It started in Vancouver, British Columbia and ended 3½ months later in San Diego. The route basically went counterclockwise around the Pacific Ocean. If I remember right, the longest single sailing without landfall was 8 days. The cost was relatively reasonable compared to some other much shorter cruises.
I was not familiar with the usage of the term “public transport” or “public transportation” being limited to local services or limited by ownership. In my dialect of English public transport includes long-distance rail and bus services, whether in private or public ownership. The term “common carrier” is not in common use where I live.
That’s claimed to be the world’s longest tram route, not the longest transit route of any kind. Lots of rural bus routes are longer.
I know we were excluding airplanes from this thread, but… The RAF charters a weekly flight from RAF Brize Norton near London to RAF Mount Pleasant on the Falkland Islands. According to Wikipedia flight is mainly for military personnel, but fare paying civilian passengers are allowed to travel on the flight. Given that the flight is heavily subsidized by the UK government and the public is allowed to travel on it, I would argue that it could be considered public transportation, at least in the way we use that term in America, the way @LSLGuy described it.
nm
Ticket to the Falklands? That would be 8,000 miles and £2,220.
Greyhound, before they went blooie, used to have a regular Toronto-to-Vancouver run. ~4000 km; around 3-4 days. That’s right: the bus never stopped for more than about an hour.
I took that bus from Toronto to Sault Ste Marie; the journey was 11 hours and I had the second-worst meal of my life in the Sudbury bus station.
A friend took the full journey. It was wretched. He’d been a bus rider all his life, and even he said, “Never again.”
I’m sure that even in North America you can buy tickets for longer bus trips, but how many of them are a single journey on the same bus?
I expect that there are longer bus trips in, say, Russia…
Friend and I were on Atlanta subway with backpacks. A kid asked where we were going and we said Alaska. He said “not on this train!” 
we were going to the airport
The schedule says Moscow to Vladivostok is 5,752 miles takes 7 days the cheap seats are $213
One of the great backpacking experiences for those who want to clock up the train miles on a low budget.