Rell Posted January 18, 2012 Share #1 Posted January 18, 2012 Do any of you know how the headways can be/are calculated? Any info would be helpful. Link to comment Share on other sites More sharing options...
The Real Posted January 18, 2012 Share #2 Posted January 18, 2012 Do any of you know how the headways can be/are calculated? Any info would be helpful. Headways are generally calculated based on service requirements throughout the course of a service day, equipment available as well as personnel available. Prime Example; If you have 300 Cars available to you for a specific line, and the line carries 10-cars, that's 30 train sets. Now you have your equipment allotment straightened out. Next, Your specific line takes 1 hour and 20 minute to travel one way end to end. Giving enough time for recovery (10 minutes max), it takes 1 train to make 1 round trip, 2 Hours and 50 minutes or 170 minutes. Using all 30 trains you can have a maximum headway of 5 1/2 minutes, but that leaves you with NO spare factor. So, now if you want to have a spare factor of say 3 trains or 30 cars, your maximum headway is now stretched out to 6-7 minutes. The easy simple equation is time of round trip divided by amount of trains available. When you start factoring in crews and what not, now you're getting in deep and that also goes along with budgeting ($$$$). So then you have to start figuring out pay and what each trip cost you to operate and then you have to figure out how much you want to charge per ride to balance your budget and/or to make a profit. It can get real complicated REAL fast. I'm a chief operating officer for a bus company as well as running my own consulting firm and on the bus company side, I have to figure these very things out in planning service. Link to comment Share on other sites More sharing options...
overclocked Posted January 19, 2012 Share #3 Posted January 19, 2012 This task would stand next to impossible, I would go as far as say that it would be harder to accomplish than full length SAS. Among other causes besides what Vintage Soul has brought up, I believe that crowd is the reason why headways can't be calculated on constant basis. People holding doors and crowding during rush hours cause trains to delay and ultimately lead all the efforts to calculate headways to go down the drain. Another reason that headways can't be calculated in my opinion is that most routes share portions of track with other routes, thus delay could happen if trains are not far from the other, since the delayed train has all the chances to slow down the one behind it. It could happen if lets say Manhattan bound is held at Church ave thanks to someone waiting for his/her whoever to get to the door and other follow. The train delays for whole whopping one minute, and by the time train leaves, the Uptown bound ( arrives at said station. It picks up passengers fast and leaves the station on time, guess what happens next. Since is scheduled to go ahead, the ( gets delayed. Depending on time of the day and schedule, this minor delay at Church Ave can lead to delays on Broadway, 6th and 8th Ave lines. I know i'm oversimplifying, and this won't happen on large scale, but I believe it's enough to cause all the calculated headways to be thrown in the garbage can. Link to comment Share on other sites More sharing options...
The Real Posted January 19, 2012 Share #4 Posted January 19, 2012 Headways can always be calculated, you're speaking in terms of maintaining headways and in that is a whole different subject. You can create and schedules headways till your face turns blue, but to make sure those headways are held day in and day out is a momentous task. Link to comment Share on other sites More sharing options...
overclocked Posted January 19, 2012 Share #5 Posted January 19, 2012 Headways can always be calculated, you're speaking in terms of maintaining headways and in that is a whole different subject. You can create and schedules headways till your face turns blue, but to make sure those headways are held day in and day out is a momentous task. Yep exactly what I meant. What's the purpose of calculating exact headways and precise schedules if they would be useless to most even before they will be printed (speaking TA wise). The pursuit of the schedule is honorable quest, but it's a lost fight before it even had started. Link to comment Share on other sites More sharing options...
The Real Posted January 19, 2012 Share #6 Posted January 19, 2012 Yep exactly what I meant. What's the purpose of calculating exact headways and precise schedules if they would be useless to most even before they will be printed (speaking TA wise). The pursuit of the schedule is honorable quest, but it's a lost fight before it even had started. You have to be in it to win it! When I was a bus operator full time before going into management, I strived and for the most part kept my schedule. That was my daily challenge and I loved doing it. Link to comment Share on other sites More sharing options...
overclocked Posted January 19, 2012 Share #7 Posted January 19, 2012 You have to be in it to win it! When I was a bus operator full time before going into management, I strived and for the most part kept my schedule. That was my daily challenge and I loved doing it. Well some things that happen are not always the things we have control over. Trains and buses break, so do people who get ill; accidents like these do mess up the schedule, and no matter how much one would try, if something happens outside of his/her control the schedule will be a total loss. Link to comment Share on other sites More sharing options...
The Real Posted January 19, 2012 Share #8 Posted January 19, 2012 Well some things that happen are not always the things we have control over. Trains and buses break, so do people who get ill; accidents like these do mess up the schedule, and no matter how much one would try, if something happens outside of his/her control the schedule will be a total loss. unless you're Trevor Logan, LMFAO! Kidding, kidding, but yes that is true! Link to comment Share on other sites More sharing options...
MikeGerald Posted January 19, 2012 Share #9 Posted January 19, 2012 There is the issue of the number of passengers served by the line in question. Frankly some lines have huge numbers of riders - meaning that the amount of resources - trains, manpower, etc. will simply have to increase up to the design limits of the transit line in question. Many transit lines are designed (like all of our subway systems) to handle 30 trains per hour on a single track, a train every 2 minutes - as per the signal system. Now whether a particular route or line should actually operate 30 trains per hour - is a whole other question. There's whole discussions about station design, the distances of stations, types of stations, track engineering, signal systems, the design of terminal stations, etc. -- all have to be considered in the creation of a transit route. Now there would not be as much door-holding if riders KNEW that they could actually board the trains, and that there is little penalty (a traveling time penalty) for catching the next train. If the trains are 2 minutes apart, (for example) catching the next train is not really a big deal - if the next train is 30 minutes away there is a big penalty for missing any train - that is the point. Just some things to keep in mind. Mike Link to comment Share on other sites More sharing options...
RTOMan Posted January 19, 2012 Share #10 Posted January 19, 2012 Good replies in this thread you learn something new everyday! Link to comment Share on other sites More sharing options...
Rell Posted January 20, 2012 Author Share #11 Posted January 20, 2012 Good replies in this thread you learn something new everyday! I must agree with you on that note. You can really learn just how much goes behind these thoughts. Link to comment Share on other sites More sharing options...
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