There are dozens of RAILROAD crossings
you have to blow the whistle for.
The Big Bang Theory Season 10, Episode 15
...a hot dog stand in a different
converted RAILROAD dining car.
The Big Bang Theory Season 4, Episode 6
Well, Sheldon was going on and on
about time zones and RAILROAD schedules,
The Big Bang Theory Season 9, Episode 16
You'd have to drive a RAILROAD spike into
his brain for me to beat him at checkers.
The Big Bang Theory Season 2, Episode 11
...an outdoor museum
featuring 43 RAILROAD engines, cars...
The Big Bang Theory Season 4, Episode 6