I spent 13 hours in a first-class sleeper car on one of Thailand's longest train rides. Here's how it compares with second and third-class travel.

The Special Express 14 takes around 13 hours, traversing nine provinces and 18 train stations. It's one of the longest routes in Thailand, spanning 467 miles.

Tourists often split up their travel between the bustling city of Bangkok, one of the top holiday destinations in the world, and the quieter, more bohemian province Chiang Mai. The northern province is known for its gorgeous natural landscape, mountains, and animal sanctuaries.

I've traveled to Thailand several times in recent years but have never traveled on a sleeper train. Since learning that the route is one of the most popular in Thailand among backpackers, I decided to book a trip and try it for myself.

There were 12 first-class cabins which were located in the second car of the train.

The cabin, while meant for two people, was really just large enough for me. There wasn't much space on board to stow luggage, so I'd recommend travelers bring minimal belongings into the cabin. Larger baggage can be stowed in the dedicated luggage compartment.

At around 6:30 p.m., a staff member came to convert the seat into two bunk beds with an attached ladder. I slept on the lower bunk and placed my belongings on the upper bunk. While the journey only had four hours of sunlight, it was worth looking at the views right from the bed.

The cabin also had an electrical socket, air-conditioning vents, and an overhead light fixture. While first-class seems value for money, it doesn't have en-suite bathrooms like the ones in Amtrak's private rooms.

While I had a decent experience in first-class, other passengers had some complaints. One passenger who traveled on first-class in March 2020 said his cabin was "so filthy," while another traveler who rode the train in July said it was "old" and said she wished staff members were more helpful.

Both bathrooms had decent amenities, with a bidet and a shower fitted with a heater, but they weren't the cleanest. I could smell the stench of urine even before opening the doors.

The second-class sleeper car had minimal amenities and was shared between several dozen passengers.

The first category of second-class offered air-conditioned convertible seats — it cost 841 baht ($23) for a lower bed and 771 baht ($21) for an upper bed. The second category comprised of non-convertible seats in a fan-only car. A ticket cost 471 baht ($12).

As the aisle was narrow, most locals chose to stow their belongings in the dedicated luggage compartment.

The lower bunk was positioned right next to the window which meant that it was one of the best seats on board for sightseeing during the golden hour. The upper bunk didn't have a window, which meant passengers missed out on the gorgeous views of northern Thailand.

The second-class sleeper cars offered some privacy: Temporary blinds are placed at the side of each bed, similar to a capsule pod in a hostel.

One passenger who traveled on the train in August said he enjoyed the "beautiful views" and appreciated how comfortable the bed was. Another passenger who rode second-class in February said she doesn't recommend the upper bed as the lights were "very bright" and she could hear every sound the air-conditioning made.

Second-class passengers also had dedicated bathrooms that one traveler described as "adequately clean."

I only saw a handful of people who chose to ride third-class. While it was affordable, costing only 311 baht ($8.50) a ticket, there was no air-conditioning.

Air-conditioning makes a big difference in how comfortable train travel is in Thailand — the average temperature in the country is around 84 degrees Farhenheit in July.

It was steaming in the car — as we were on a railway train, the train itself was emitting a lot of heat that just made Thailand's hot and humid weather feel more intense.

I can imagine just how uncomfortable a 13-hour ride in a non-air conditioned seat would be, but locals told me they rode third-class to save as much money as possible. While tourists ride on the Sleeper Express to see more of Thailand's countryside or to experience what a train ride is like in the country, locals travel on it to get to the capital in a cost-effective way.

"It's better than flights if you want to take a lot of luggage for a small amount of money," a local tour guide, Uma Puacksumran, told me.

While the price of a one-way plane ticket from Chiang Mai to Bangkok can be as cheap as $14.50, excess luggage fees can pile up and add on to the cost.

One upside to third-class was that it was spacious — there were so few people on board the car that there weren't any lines to use the wash basins or bathrooms.

But that's apparently not always the case.

One blogger named Chris said that third-class was often "overcrowded" especially with shorter train trips. He also warned that maintenance in third-class can be poor — seats can be hard and the fans might not work.