“Beware the empty train car in rush hour” was posted on Twitter by T. Reynolds/Terry N on March 31, 2010. “Always beware the empty subway car” was posted on Twitter by author and illustrator Nathan W. Pyle on July 24, 2010.
 
The empty subway train car is empty for a reason. It probably has no heat or air conditioning. A homeless person could be stinking up the car. Also, it’s dangerous to be in a subway car without other people to provide safety.
 
The saying has been printed on several images. This is from Nathan W. Pyle’s book, NYC Basic Tips and Etiquette (2014):
 
“NYC BASIC TIPS AND ETIQUETTE #30
BEWARE THE EMPTY TRAIN CAR. IT’S EMPTY FOR A REASON.”
   
   
Twitter
T. Reynolds/Terry N
@Tea_Rey
Beware the empty train car in rush hour.
8:52 AM · Mar 31, 2010·Twitter Web Client
     
Twitter
Nathan W. Pyle
@nathanwpyle
Always beware the empty subway car
4:51 PM · Jul 24, 2010·Twitter Web Client
   
Twitter
Jesse Spector
@jessespector
Beware the empty subway car. Unless you like the smell of human feces. In which case, may No. 5547 on the R line be your chariot.
3:44 PM · Feb 3, 2011·twidroyd (original)
 
Twitter
Jordan Kaleh
@DJRobDollars
Beware the empty train car, you may sit, but it may stank!
8:22 PM · Feb 10, 2011·TweetDeck
 
Twitter
JF Hall
@JFHallWrites
Beware the empty train car…. #mta #advice #stinky
11:41 AM · Dec 11, 2011·Twitter SMS
 
Twitter
Jonathan Fincher
@jonathanfincher
“NYC Basic Tips and Etiquette #56: Beware the empty train car. It’s empty for a reason.” So horrifyingly true. http://imgur.com/a/rEj7m
1:04 PM · Mar 25, 2013·Twitter Web Client
 
New York magazine—Intelligencer
STAND CLEAR OF THE CLOSING DOORS AUG. 13, 2013
10 NYC Subway Tricks and Neighborhood Tips, in GIFs
By Joe Coscarelli
Nathan W. Pyle, a native of Ohio, has lived in New York City for four years now and feels like he has some wisdom to share. Luckily, he’s also an illustrator and has a knack for getting across information in GIF form, so it’s both entertaining and elucidating. A book of his info-comics, NYC Basic Tips and Etiquette, is due out in 2014, but Pyle has shared some outtakes and never-before-seen images with Daily Intelligencer.
       
Twitter
WNYC 🎙
@WNYC
Beware the empty train car! 10 subway tips in GIFs http://nym.ag/1eH1aF0
12:29 PM · Aug 13, 2013·Sprout Social
 
sirBenjaminZ
@Benjamin21st
Aug 13, 2013
Replying to @WNYC
@WNYC I once went into an empty car with two friends, and we were almost suffocated by the stinky smell! DON’T EVER GO INTO AN EMPTY CAR!!!!
 
OCLC WorldCat record
NYC basic tips and etiquette
Author: Nathan W Pyle
Publisher: New York : William Morrow, an imprint of HarperCollins Publishers, [2014]
Edition/Format:   eBook : Document : English : First edition
Summary:
Living in New York City for five years as a transplant from Ohio, illustrator and T-shirt designer Nathan Pyle was fascinated by the unique habits and unspoken customs New Yorkers follow to make life bearable in a city with 8 million people (and seemingly twice the number of tourists). Nathan decided to draw his favorite tips and etiquette lessons and post them on the internet, where his 12 original panels went viral immediately and became the basis for this hilarious illustrated book (check out the fully animated ebook, too!). In NYC Basic Tips and Etiquette, Pyle reveals the secrets and unwritten rules for living in and visiting New York including the answers to such burning questions as, which cabs should I try to hail’ What is a bodega’ Which way is Uptown’ Why are there so many doors in the sidewalk’ How do I walk on an escalator’ Do we need to be touching right now’ Where should I inhale or exhale while passing sidewalk garbage’ How long should I honk my horn’ If New York were a game show, how would I win’ What happens when I stand in the bike lane’ Who should get the empty subway seats’ How do I stay safe during a trash tornado’ Each tip is a little story illustrated in simple black and white drawings. Visitors and newcomers to New York will love it because the advice is smart, funny, and not condescending. New Yorkers will love it for its strategic and humorous approach to mastering the daily chaos of the city.
   
Twitter     
Rani Molla
@ranimolla
“Beware the empty train car. It’s empty for a reason.” Great animated NYC advice: http://news.distractify.com/culture/nyc-tips-and-etiquette/?v=1
12:13 PM · Sep 12, 2014·Twitter Web Client
 
Twitter   
Rick
@randomgotham
Beware the empty train car; ignore the temptations of a plethora of seats. #MTA #morningcommute #NYCSubway
7:28 AM · Aug 15, 2015 from Queens, NY·Twitter for iPhone
 
Twitter
💵 iPhoneGalaxyMD
@iphonegalaxymd
NYC Basic tips & etiquette #30:
Beware the empty train car. It’s empty for a reason.
8:58 AM · Aug 17, 2015·Buffer
     
The Regular Guy—NYC
THE DANGER OF ENTERING AN EMPTY NYC SUBWAY CAR!
04/26/2015 FILBIO310
(...)
I walked into an empty subway car on the way home from work yesterday.
 
Twitter
Aria Finger
@AriaIrene
#1 rule for ppl new to New York: Beware the empty subway car!
7:48 AM · Jun 14, 2016·Twitter for iPhone
 
Porter Mason
@portermason
Jun 14, 2016
Replying to @AriaIrene
Unless you want a free sauna!
   
Britney Fitzgerald
NEW YORK TIP #4: NEVER ENTER AN EMPTY SUBWAY CAR
October 9, 2016
(...)
I spotted an empty-ish car and quickly began waking toward it. In summer, I had already learned that an unpopulated section of the train typically means one of two things: Either the AC isn’t working and you will sweat until you can’t see straight, or there is a very unpleasant smell waiting to attack your gag reflexes. But it was currently the dead of winter, so I took my chances.
 
Twitter
Marjolein Suzanne
@MarjoleinSuz
Beware the empty train car, it’s empty for a reason - #newyorkcity #subway #columbuscircle… https://instagram.com/p/BTIiV1LDEB-/
12:06 AM · Apr 21, 2017·Instagram
 
Twitter
Naima Cochrane
@naima
Beware the empty train car
- Ancient NYC proverb
7:16 PM · Aug 21, 2018·Twitter for iPhone
 
Twitter
I am the popo
@emilypoliti
Beware the empty subway car: it is probably NOT air conditioned
1:08 PM · Jun 27, 2019·Twitter for Android