Final answer:
The truthfulness of the conductor's greeting cannot be determined without a specific bulletin. However, it is common for conductors to greet passengers as part of quality customer service in public transportation.
Step-by-step explanation:
The statement in the question seems to be lacking sufficient context to determine its truthfulness. Public transportation cultures and behaviors do vary significantly across different cities and countries, as detailed in the references provided. Generally, a conductor greeting passengers when they are boarding a train, such as the hypothetical D train at Coney Island, is a common customer service practice. However, without specific details from a real bulletin, we cannot assess the truth of this particular statement.
What we can deduce from the various examples is that the experience of commuting is universal, with certain expected behaviors such as finding a bus stop or station, paying a fare to an agent, and finding a seat. Nevertheless, local cultural practices and the capacity of the transportation system can dictate deviations from these norms, leading to different passenger behaviors like those described in Cairo, Dublin, Mumbai, and other cities.