Q: Often when I am taking the train from downtown Manhattan to Queens this happens to me: I ride the local until 14th Street, planning to change trains and take the express. As I arrive the express is waiting, but as soon as I get out it takes off without me. Is there a policy for express trains waiting for locals?

A: During peak hours, which are defined by New York City Transit as between 6:30 a.m. and 9:30 a.m. and 3:30 p.m. and 8 p.m., trains stick to their schedules as strictly as possible. So if you happen to be getting off a local train at the 14th Street station and are hoping to catch the express (or vice versa) immediately, you may be out of luck. Transit spokesman James Anyasi said the train conductor is ordered not to hold doors open during these hours.

However, during non-rush hour periods, there are scheduled connections. That means the train conductor is ordered to give you enough time to cross between trains before leaving the station.

The rationale is simple, Mr. Anyasi said: “Although we regret any inconvenience to our customers, the delay due to the increased dwell times necessary to provide connections would cause congestion and adversely affect rush-hour service.”

There are so many signs saying we shouldn’t pull the emergency cord, but there aren’t any signs that say when we should actually use it. Under what circumstances are we supposed to pull it?

All train cars have emergency cords, which stop the train immediately when pulled. No matter where you are – in the middle of a long, dark tunnel, halfway out of a station, or even on a bridge – the train will come to a screeching halt. And to start the train up again, the brakes have to be reset manually by the train conductor, the transit spokesman, Mr. Anyansi said.

If, for instance, someone is walking between cars when the train is in operation and they slip, you should pull the cord immediately. You might save that person’s life. (Traveling between cars when the train is moving is against MTA policy and carries a fine.)

But if someone is hurt inside the train car or a crime has been committed, it won’t help anyone if the train is stranded between stations. Ambulances can easily access a victim through the train platform, but it’s another story getting emergency personnel through the tunnel. In most emergencies, pulling the cord will simply delay getting help to whoever needs it. It remains in place for an especially drastic emergency – like when someone falls onto the tracks, Mr. Anyansi said.

There are emergencies that warrant immediately stopping the train, but most often it would be better to communicate with the conductor after the train has reached a station. This way, help can arrive as quickly as possible.

Questions? Write transit@nysun.com.