Local or Express?

June 19, 2007 6:36 AM

Help me optimize my daily New York City Subway commute! A good question for those who love transportation puzzles:

Every business day, I travel from Union Square to Grand Central at 8:30AM and return at 5:30PM via the 4,5 or 6 train. These trains depart from opposite sites of the same platform. Given the frequency of the trains, and their comparative speeds (and the fact that the local stops along the way), am I better off:

1. Always getting on the first train that arrives, be it local (6) or express (4,5)
2. Always getting on the first express train that arrives, even if that means not getting on a local train (4,5)
3. Some other answer?

Why?

Now, say I just miss an express train (i.e. see it depart the station), am I better off:

1a. Getting on the next train to arrive, be it local or express (4,5 or 6)
2a. Getting on the next express train to arrive even if that means skipping a local train (4,5)
3a. Some other option?

Why?

I am assuming in this question that I always can board any train, but if I estimate that the express trains are too crowded 10% of the time, and the local trains are never too crowded, does that change your answer?

posted by 2bucksplus to travel & transportation (16 comments total)

In my experience, going that short a distance doesn't warrant waiting for the express train. You should get on whichever train comes first. Those three extra stops will probably take ~5 minutes more, and there's no way to guarantee that the express will come within five minutes. Plus, you get the luxury of not being overcrowded.
posted by one_bean at 6:47 AM on June 19, 2007

Based solely on the official schdules, the MTA says the 4 train runs every 4-7 Minutes, and takes about 9 to 10 minutes from Brooklyn Bridge to Grand Central and the same for the 5. That means it likely takes 4-5 minutes to go from Union Square.

The 6 train runs about every 4 minutes and takes about 10 minutes to make the same trip.

So if the 4 or 5 takes 6 minutes to come (assuming equal intervals) and a 5 minute journey, that's 11 minutes. If the 6 train takes 4 minutes and a 10 min journey, that's 14. However, if the 4/5 just left and a 6 just pulled in, you'd probably be better on the 6 (10 min vs. 11).

This is all fuzzy math and not taking into account the MTA's unpredictability. Again, check the schedules for more info
posted by yeti at 6:58 AM on June 19, 2007

Awesome yeti, just the kind of answer I was looking for!
posted by 2bucksplus at 7:05 AM on June 19, 2007

If you see me on the platform, make sure to avoid whatever train I get on -- its guaranteed to stop fifty times in the tunnel.
posted by ben242 at 7:59 AM on June 19, 2007

3. You should take the 6 because it's almost always less crowded and delay-prone than the 4, which is the worst subway in the city during rush hour, IMO.

4. Just walk. It's not far and less stressful.
posted by mkultra at 8:05 AM on June 19, 2007

takes about 9 to 10 minutes from Brooklyn Bridge to Grand Central and the same for the 5. That means it likely takes 4-5 minutes to go from Union Square.

Except there is a pretty standard slowdown between Grand Central and Union Square (just like the B/D always get stuck behind A/Cs outside Columbus Circle during rush hour). So often on that route, the 6 is faster, despite stopping more. But sometimes it isn't.
posted by dame at 8:14 AM on June 19, 2007

I get on the 6 train at Astor place and ride north to Grand Central. I rarely switch to the express at Union Square. The time differences between the two trains you are looking for is quite small - a matter of 2-3 minutes. Given that the 4-5 often is cantankerous and tends to slow down sometimes (see dame's comment), I suggest that, if you really want to optimize your commute, you make comfort, not speed, your primary concern.
posted by taliaferro at 8:28 AM on June 19, 2007

As I said, there's about a 4-5 minute difference in the express or the local. The only time it makes sense to let the 6 go and wait for the 4/5 is if you know for a fact that it will be there within 4 minutes. Given that its average time is 4-7 minutes, and in fact can be longer, there is no way to know whether it will come in time.

Often what happens with trains during the morning commute is that two will come in rapid succession, and another won't arrive for another 10 minutes. This happens because the first train gets slowed down by all the passengers who have been waiting, while the train behind it catches up, stopping only for the few passengers who happened to arrive in between those.

In other words, if you let the 6 go by, you could still be at Union Square while it's arriving at Grand Central. If you look down the track and see the 4/5 arriving, wait for it. Otherwise, if the 6 is there, get on.
posted by one_bean at 8:28 AM on June 19, 2007

Interesting -- I just plugged in Union Square to Grand Central on Tuesday at 8:30am into Hopstop and it gave me:

4 train - 13 minutes
5 train - 14 minutes
6 train - 16 minutes

On the way home, from Grand Central to Union Square at 5:30pm on a Tuesday, it gave the same estimates.
posted by kathryn at 8:38 AM on June 19, 2007

This happens because the first train gets slowed down by all the passengers who have been waiting, while the train behind it catches up, stopping only for the few passengers who happened to arrive in between those.

Seriously, subway pro-tip: There is always an empty train behind the full train. Yet the majority of humans insist on cramming in to the full train. Wait two minutes. You may spend 30s longer in the tunnel, but you will be sitting, in AC, far from the BO guy who you know follows you.
posted by dame at 9:27 AM on June 19, 2007

Also, no one calls it the green line. Don't do that. We are against it here.
posted by dame at 9:28 AM on June 19, 2007

Seriously, subway pro-tip: There is always an empty train behind the full train. Yet the majority of humans insist on cramming in to the full train. Wait two minutes. You may spend 30s longer in the tunnel, but you will be sitting, in AC, far from the BO guy who you know follows you.

However, if you take that 2nd train, by the time you get to your station, the exits will be flooded with slow walkers from the first, crammed train.
posted by kathryn at 10:40 AM on June 19, 2007

Lol. That is a complicated variable. Depends where you get off, which stops are in between, etc. Still worth avoiding the squish train, I say!
posted by dame at 10:58 AM on June 19, 2007

you should test this out with a stopwatch for two weeks (one week express only, one week whichever train comes first) and let us know the results. I prefer the "whichever train comes first" strategy.
posted by chelseagirl at 11:04 AM on June 19, 2007

So if the 4 or 5 takes 6 minutes to come (assuming equal intervals) and a 5 minute journey, that's 11 minutes.

Well, not really: a 4 train arrives every 4-7 minutes, and a 5 train arrives every 4-7 minutes. But since one doesn't discriminate between the two on this journey, a more helpful estimate might be that either a 4 or 5 train will arrive in 3 minutes, for an estimated 8-minute journey.

But in real life, I also agree with the practical advice offered by later commenters.
posted by deadfather at 11:23 AM on June 19, 2007

Great question. As has been mentioned, the distance is short enough that this comes down to what you value most. You have to evaluate the reward of getting there slightly earlier vs. the reward of not being crammed on an express.

For example, I've been groped on crowded trains enough times (and, once, pickpocketed) that in my value system "relatively empty train" trumps "slightly shorter ride." Your mileage may vary.

(And I agree with dame, also for safety reasons -- just never call it the "green" line out loud since that's like a sign that says "I'm new here, please mug me...")
posted by sparrows at 3:44 PM on June 20, 2007