Which of the following are used to mark railway crossings on public roads?

• A large red and white “X” sign
• Red light signals
• A barrier or gate
• All of the above
  Explanation:

  "Railway crossings are marked using various warning methods, including a large red and white “X” sign, red light signals, and barriers or gates. These signs and signals alert drivers of the presence of a train for safety at crossings."