Controlling System Costs: Basic and Advanced Scheduling Manuals and Contemporary Issues in Transit Scheduling (2009) / Chapter Skim
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From page 32... ...
Chapter 3. Schedule Building ͯ.ͭ Building a Simple Schedule (Level ͭ)
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Service patterns are a fundamental component of scheduling and provide the framework for tracking running time, generating revenue trips, and identifying deadhead movements for the route. deadhead The time and distance that a bus needs to travel in places where it will not pick up passengers.
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cycle time Sum of the round-trip running time plus layover time. Also known as "round trip cycle time." schedule pattern A summary of the schedule in terms of running times between time points and layover time at terminals.
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If the union contract does not address layover, past practice may guide the allocation of layover time. An example of minimum layover is ͭͬ% of the running time or six minutes per round-trip, whichever is greater.
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We will see examples of schedules with lots of variations in the intermediate and advanced sections later in this chapter. Never reduce a minimum required layover time or calculated running time to "squeeze" the cycle to better fi t the headway.
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Think about who will look at the sheet, and how it will be used. Should fi xed inputs (running times, mileage, etc.)
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Follow that with Column N for Pull-in. Your spreadsheet will look like this: A quick note about the term "block." This is the term for the vehicle (bus, light rail vehicle or train, heavy rail train, etc.)
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In this case, since the running time and headway is constant, the schedule pattern will summarize operation for the entire day. P Q R 1 2 3 4 5 6 7 Run Time Distance 8 A - 9 B 8 1.4 10 C 14 2.9 11 D 11 2.2 12 Total 33 6.5 13 14 15 16 Run Time Distance 17 D 18 C 11 2.2 19 B 14 2.9 20 A 8 1.4 21 Total 33 6.5 22 23 24 Garage Deadheads 25 Run Time Distance 26 To "A" 10 3.5 27 To "D" 20 6.8 28 29 30 0:06 31 0:10 32 0:12 33 0:15 34 0:20 35 0:30 36 1:00 Westbound Headway Options Running Time/Mileage Definitions Eastbound Note that we enter various clock face headway options in time format in cells Q30: Q36.
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Schedule Building 3-10 First, we enter a time for the fi rst eastbound trip. We start with Ͳ:ͬͬ and our schedule pattern sheet looks like this: The arrival time at Point D, the end of the route, is a simple formula that takes the depart time cell and adds the running time (also defi ned in the spreadsheet)
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We now have a schedule pattern that we simply begin at the start of the day and end when we want our service to end. And we know how many buses we need.
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A typical range is 0 to 5 minutes after the scheduled arrival/departure time. A trip that leaves a time point early is referred to as "hot" or "running hot."
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Building a Simple Schedule Then, after we copy the formula in row ʹ down columns C and H (corresponding to the leave times at points A and D) , we have the basic schedule populated throughout the day: A B C D E F G H I J K L M N 1 Example Headway Sheet #1 2 ROUTE 97 Broad Street 3 DAY Weekday 4 5 Block # Pull Out A B C D D C B A Next Trip Pull In 6 6:15 6:48 7:00 7 6:00 6:33 6:45 7:18 7:30 8 6:30 7:15 8:00 9 7:00 7:45 8:30 10 7:30 8:15 9:00 11 8:00 8:45 9:30 12 8:30 9:15 10:00 13 9:00 9:45 10:30 14 9:30 10:15 11:00 15 10:00 10:45 11:30 16 10:30 11:15 12:00 17 11:00 11:45 12:30 18 11:30 12:15 13:00 19 12:00 12:45 13:30 20 12:30 13:15 14:00 21 13:00 13:45 14:30 22 13:30 14:15 15:00 23 14:00 14:45 15:30 24 14:30 15:15 16:00 25 15:00 15:45 16:30 26 15:30 16:15 17:00 27 16:00 16:45 17:30 28 16:30 17:15 18:00 29 17:00 17:45 18:30 30 17:30 18:15 19:00 31 18:00 18:45 32 18:30 19:15 33 19:00 Eastbound Westbound
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Cells Q͵ through Qͭͭ contain eastbound running times, while cells Qͭʹ through Qͮͬ contain westbound running times. Using the "show formula" feature of Excel, we enter the following formulas in Row ͳ (eastbound)
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Chapter 3. Schedule Building 3-15 Level ͭ.
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We can partially justify it by being closer to the garage when the trip is over. A B C D E F G H I J K 1 Example Headway Sheet #1 2 ROUTE 97 Broad Street 3 DAY Weekday 4 5 Block # Pull Out A B C D D C B A 6 6:15 6:26 6:40 6:48 7 6:00 6:08 6:22 6:33 6:45 6:56 7:10 7:18 8 6:30 6:38 6:52 7:03 7:15 7:26 7:40 7:48 9 7:00 7:08 7:22 7:33 7:45 7:56 8:10 8:18 10 7:30 7:38 7:52 8:03 8:15 8:26 8:40 8:48 11 8:00 8:08 8:22 8:33 8:45 8:56 9:10 9:18 12 8:30 8:38 8:52 9:03 9:15 9:26 9:40 9:48 13 9:00 9:08 9:22 9:33 9:45 9:56 10:10 10:18 14 9:30 9:38 9:52 10:03 10:15 10:26 10:40 10:48 15 10:00 10:08 10:22 10:33 10:45 10:56 11:10 11:18 16 10:30 10:38 10:52 11:03 11:15 11:26 11:40 11:48 17 11:00 11:08 11:22 11:33 11:45 11:56 12:10 12:18 18 11:30 11:38 11:52 12:03 12:15 12:26 12:40 12:48 19 12:00 12:08 12:22 12:33 12:45 12:56 13:10 13:18 20 12:30 12:38 12:52 13:03 13:15 13:26 13:40 13:48 21 13:00 13:08 13:22 13:33 13:45 13:56 14:10 14:18 22 13:30 13:38 13:52 14:03 14:15 14:26 14:40 14:48 23 14:00 14:08 14:22 14:33 14:45 14:56 15:10 15:18 24 14:30 14:38 14:52 15:03 15:15 15:26 15:40 15:48 25 15:00 15:08 15:22 15:33 15:45 15:56 16:10 16:18 26 15:30 15:38 15:52 16:03 16:15 16:26 16:40 16:48 27 16:00 16:08 16:22 16:33 16:45 16:56 17:10 17:18 28 16:30 16:38 16:52 17:03 17:15 17:26 17:40 17:48 29 17:00 17:08 17:22 17:33 17:45 17:56 18:10 18:18 30 17:30 17:38 17:52 18:03 18:15 18:26 18:40 18:48 31 18:00 18:08 18:22 18:33 18:45 18:56 19:10 19:18 32 18:30 18:38 18:52 19:03 19:15 19:26 19:40 19:48 33 19:00 19:08 19:22 19:33 Eastbound Westbound
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Once you have defi ned the route, time points, running times, and distances in your system, trips are easy to create and manipulate. But what time should the trips start?
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Level ͭ. Building a Simple ScheduleChapter 3.
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To refresh our memory, the minimum acceptable cycle (round-trip running time of ͲͲ minutes plus the prescribed minimum layover) is ͳͯ minutes.
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Split runs tend to be used to allow both peaks to be covered by one operator since the work day would otherwise be too long for a straight run. pieces Portions of a run, especially distinct portions separated by a break.
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Intermediate Schedule Building Even if your system does not have a required amount of layover, always ask yourself whether the route can be expected to run on time given traffi c conditions and a designated amount of layover. Tip 1 Example Headway Sheet #2 2 ROUTE 97 Broad Street 3 DAY Weekday 4 5 Block # Pull Out A B C D D C B A Next Trip Pull In 6:00 6 3 5:55 6:15 6:26 6:40 6:48 7:00 6:30 7 1 5:50 6:00 6:08 6:22 6:33 6:45 6:56 7:10 7:18 7:30 6:15 7:00 8 2 6:20 6:30 6:38 6:52 7:03 7:15 7:26 7:40 7:48 8:00 6:45 7:30 9 3 7:00 7:08 7:22 7:33 7:45 7:56 8:10 8:18 8:30 7:15 8:00 10 1 7:30 7:38 7:52 8:03 8:15 8:26 8:40 8:48 9:00 7:45 8:30 11 2 8:00 8:08 8:22 8:33 8:45 8:56 9:10 9:18 9:30 8:15 9:00 12 3 8:30 8:38 8:52 9:03 9:15 9:26 9:40 9:48 10:00 8:45 13 1 9:00 9:08 9:22 9:33 9:45 9:56 10:10 10:18 10:30 14 2 9:30 9:38 9:52 10:03 10:15 10:26 10:40 10:48 11:00 15 3 10:00 10:08 10:22 10:33 10:45 10:56 11:10 11:18 11:30 16 1 10:30 10:38 10:52 11:03 11:15 11:26 11:40 11:48 12:00 17 2 11:00 11:08 11:22 11:33 11:45 11:56 12:10 12:18 12:30 18 3 11:30 11:38 11:52 12:03 12:15 12:26 12:40 12:48 13:00 19 1 12:00 12:08 12:22 12:33 12:45 12:56 13:10 13:18 13:30 20 2 12:30 12:38 12:52 13:03 13:15 13:26 13:40 13:48 14:00 21 3 13:00 13:08 13:22 13:33 13:45 13:56 14:10 14:18 14:30 22 1 13:30 13:38 13:52 14:03 14:15 14:26 14:40 14:48 15:00 23 2 14:00 14:08 14:22 14:33 14:45 14:56 15:10 15:18 15:30 24 3 14:30 14:38 14:52 15:03 15:15 15:26 15:40 15:48 16:00 25 15:30 1 15:00 15:08 15:22 15:33 15:45 15:56 16:10 16:18 16:30 26 15:15 16:00 2 15:30 15:38 15:52 16:03 16:15 16:26 16:40 16:48 17:00 27 15:45 16:30 3 16:00 16:08 16:22 16:33 16:45 16:56 17:10 17:18 17:30 28 16:15 17:00 1 16:30 16:38 16:52 17:03 17:15 17:26 17:40 17:48 18:00 29 16:45 17:30 2 17:00 17:08 17:22 17:33 17:45 17:56 18:10 18:18 18:30 30 17:15 18:00 3 17:30 17:38 17:52 18:03 18:15 18:26 18:40 18:48 19:00 31 17:45 32 1 18:00 18:08 18:22 18:33 18:45 18:56 19:10 19:18 19:28 33 2 18:30 18:38 18:52 19:03 19:15 19:26 19:40 19:48 19:58 34 3 19:00 19:08 19:22 19:33 19:53 Eastbound Westbound AM peak period The period in the morning when the greatest level of service is provided, typically 6 to 9 AM.
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Diff erent running times during the day. Running times may change several times during the day to take into account diff erent operating speeds due to congestion, loads, or other factors.
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Intermediate Schedule Building In this case we have decided that our preference would be to give three minutes at "D" as the "away" terminal and the remaining six at "A." Three provides the buff er we are looking for. Remember that we have done a bang-up job of calculating the running time for accuracy, so we are only concerned with providing that extra buff er for conditions beyond the ordinary.
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This second schedule adds the complication of changing from a ͭͱ-minute during the AM peak to a ͯͬ-minute in the midday, back to a ͭͱ-minute in the PM Peak and fi nally back to a ͯͬ-minute headway during the course of an operating day. The next section will introduce a schedule with variable running time.
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But a good scheduler always studies a headway (or running time) transition to see the result.
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The off -peak schedule pattern now looks like this: Note that one disadvantage of this approach is that the layover time at point A is now ͮͭ minutes. Many schedulers would be uncomfortable with this amount of layover, and might choose the fi rst approach to avoid a long layover at one point.
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Intermediate Schedule Building Transitioning allows service to ease into a new pattern, generally matching service to demand which often changes more gradually over the service day. Tip 1 Example Headway Sheet #2 2 ROUTE 97 Broad Street 3 DAY Weekday 4 5 Block # Pull Out A B C D D C B A Next Trip Block Pull In 6 6:06 6:17 6:31 6:39 6:45 7 6:21 6:32 6:46 6:54 7:00 8 6:00 6:08 6:22 6:33 6:36 6:47 7:01 7:09 7:15 9 6:15 6:23 6:37 6:48 6:51 7:02 7:16 7:24 7:30 10 6:30 6:38 6:52 7:03 7:06 7:17 7:31 7:39 7:45 11 6:45 6:53 7:07 7:18 7:21 7:32 7:46 7:54 8:00 12 7:00 7:08 7:22 7:33 7:36 7:47 8:01 8:09 8:15 13 7:15 7:23 7:37 7:48 7:51 8:02 8:16 8:24 8:30 14 7:30 7:38 7:52 8:03 8:06 8:17 8:31 8:39 8:45 15 7:45 7:53 8:07 8:18 8:21 8:32 8:46 8:54 9:00 16 8:00 8:08 8:22 8:33 8:36 8:47 9:01 9:09 17 8:15 8:23 8:37 8:48 8:51 9:02 9:16 9:24 9:30 18 8:30 8:38 8:52 9:03 9:06 9:17 9:31 9:39 10:00 19 8:45 8:53 9:07 9:18 20 9:00 9:08 9:22 9:33 9:36 9:47 10:01 10:09 10:30 21 9:30 9:38 9:52 10:03 10:06 10:17 10:31 10:39 11:00 22 10:00 10:08 10:22 10:33 10:36 10:47 11:01 11:09 11:30 23 10:30 10:38 10:52 11:03 11:06 11:17 11:31 11:39 12:00 24 11:00 11:08 11:22 11:33 11:36 11:47 12:01 12:09 12:30 25 11:30 11:38 11:52 12:03 12:06 12:17 12:31 12:39 13:00 26 12:00 12:08 12:22 12:33 12:36 12:47 13:01 13:09 13:30 27 12:30 12:38 12:52 13:03 13:06 13:17 13:31 13:39 14:00 28 13:00 13:08 13:22 13:33 13:36 13:47 14:01 14:09 14:30 29 13:30 13:38 13:52 14:03 14:06 14:17 14:31 14:39 15:00 30 14:00 14:08 14:22 14:33 14:36 14:47 15:01 15:09 15:15 31 14:30 14:38 14:52 15:03 15:06 15:17 15:31 15:39 15:45 32 15:21 15:32 15:46 15:54 16:00 33 15:00 15:08 15:22 15:33 15:36 15:47 16:01 16:09 16:15 34 15:15 15:23 15:37 15:48 15:51 16:02 16:16 16:24 16:30 35 15:30 15:38 15:52 16:03 16:06 16:17 16:31 16:39 16:45 36 15:45 15:53 16:07 16:18 16:21 16:32 16:46 16:54 17:00 37 16:00 16:08 16:22 16:33 16:36 16:47 17:01 17:09 17:15 38 16:15 16:23 16:37 16:48 16:51 17:02 17:16 17:24 17:30 39 16:30 16:38 16:52 17:03 17:06 17:17 17:31 17:39 17:45 40 16:45 16:53 17:07 17:18 17:21 17:32 17:46 17:54 18:00 41 17:00 17:08 17:22 17:33 17:36 17:47 18:01 18:09 42 17:15 17:23 17:37 17:48 17:51 18:02 18:16 18:24 18:30 43 17:30 17:38 17:52 18:03 18:06 18:17 18:31 18:39 19:00 44 17:45 17:53 18:07 18:18 45 18:00 18:08 18:22 18:33 18:36 18:47 19:01 19:09 Eastbound Westbound
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Is the transition from peak to off -peak and back again the way we want it? If so, we have achieved the results we planned for in our schedule pattern-building exercise.
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Chapter 3. Schedule Building 3-29 Level ͮ.
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Tip Min ot Libby Sand Point Wi sh ram Shelby Es sex Pasco Pasco Pasco Br oa dw ay Rugby Circle Wi llis ton Ha vre 96A 96 Time point Garage ROUTE 96 -- PASCO AVENUE
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Intermediate Schedule Building S C HE D UL E S HE E T Ro u te 96 IN EF F : S eptem ber 15, 2007 M O NDAY T HRU F RIDAY P art 1 NO RTHB O UND S O UTHB O UND OUT Libby Sand Pasco Pasco Pasco Rugby Rugby Pasco Pasco Pasco Sand Libby IN BLK GAR Wishrm Point Essex Havre Willis Circle Circle Willis Havre Essex Point Wishrm GAR LVE.
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Schedule Building 3-32 S C HE D UL E S HE E T Ro u te 96 IN EF F : S eptem ber 15, 2007 M O NDAY T HRU F RIDAY P art 2 NO RTHB O UND S O UTHB O UND OUT Libby Sand Pasco Pasco Pasco Rugby Rugby Pasco Pasco Pasco Sand Libby IN BLK GAR Wishrm Point Essex Havre Willis Circle Circle Willis Havre Essex Point Wishrm GAR LVE.
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; the second calculates the average load per trip within the time interval. Average load per trip within the time interval is shown in bold on the load average spreadsheet.
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Schedule Building 3-34 peak of the peak The absolute busiest time interval (measured in short increments such as 15 or 30 minutes, depending on headway) during the peak period, in terms of passenger demand and service.
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Intermediate Schedule Building Route ͵Ͳ operates past the maximum load point every ͭͱ minutes during the base period and every ͭͬ during the peaks. So the peak periods are divided into ͯͬ-minute intervals and the base period into Ͳͬ-minute intervals.
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. A simple calculation shows that a fourth trip during this half hour would bring the average load down to slightly more than ͯ͵.
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Intermediate Schedule Building most of the trips in the peak, as well as during other times in the operating day, seem to be arriving late. A running time analysis is appropriate before crafting a fi nal change proposal.
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The next step is analyzing running time.
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The spreadsheet has two columns beside the observed running time totals that show the present running time period breaks and the scheduled running time. The bold horizontal lines mark the beginning and end of periods for which running times will be averaged.
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Schedule Building 3-40 Establishing Running Time Periods There are two separate steps in analyzing running time: ͭ. Break the operating day down into individual running time periods for each direction ͮ.
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Intermediate Schedule Building Trip Total Time 5:06 42 5:26 44 5:40 43 5:55 46 6:10 49 6:20 48 6:20 51 6:40 49 6:50 50 7:00 53 7:10 55 7:20 54 7:30 56 7:40 55 7:50 54 8:00 55 8:10 53 8:20 51 8:35 49 8:50 48 9:05 50 9:25 47 9:45 46 10:05 47 The fi gures represent total trip times during the early morning, AM peak, and mid morning base periods. On fi rst glance, it looks as if there is no order at all to totals, much less a trend.
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Likewise, there is a similarity in running times between ͳ:ͬͬ and ʹ:ͭͬ. The times range between ͱͯ and ͱͲ minutes and average ͱͰ.Ͱ minutes.
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The average of all six trips is Ͱʹ.ʹ rounded to Ͱ͵, about halfway between the adjacent averages. In this case, the decision is to go with the Ͱ͵ and just one transition running time period.
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Laying out individual running time observations this way provides an ideal way of looking at trends. As noted earlier, the spreadsheet has two columns beside the observed running time totals that show the present running time period breaks and the scheduled running time.
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Intermediate Schedule Building HE AD W A Y S HE ET L i n e 96 IN EFF : S eptem ber 15, 2007 M O NDA Y T HRU F RIDA Y H E A D W A Y W ITH 3 -D A Y RUNN IN G TIM E C H E C K S A D D E D DIRE CTIO N = NO RTH - S O UTH A M Libby Sand Pasco Pasco Pasco Rugby Avg Avg Proposed Proposed Rugby Pasco Pasco Pasco Sand Libby IN Avg Avg Proposed Proposed Wishrm Point Essex Havre Willis Circle Lib/Wsh Sand Pt Lib/Wsh Sand Pt Circle Willis Havre Essex Point Wishrm GAR Lib/Wsh Sand Pt Sand Pt Lib/Wsh 5:05 5:19 5:29 5:37 5:46 5:50 5:59 6:07 6:17 6:27 5:19 5:29 5:39 5:47 5:56 6:05 6:14 6:22 6:32 6:42 9.5 8 9 10 10 7.5 9.5 9 9 7.5 10 9 9.5 7.67 9.5 9.33 36 5:35 5:49 5:59 6:07 6:16 6:20 6:29 6:37 6:47 6:57 37 37 9 8 10 9.5 8.5 8.5 9.5 9.5 9.5 8 11 10 9 8.17 10 .2 9.67 37 5:49 5:59 6:09 6:17 6:26 6:35 6:44 6:52 7:02 7:12 41 37 9.5 8 10 10 8.5 9 9.5 9.5 9.5 9 9.5 9.5 9.17 8.67 9.67 9.67 37 6:05 6:19 6:29 6:37 6:46 6:50 7:01 7:10 7:21 7:32 14 9.5 8 9.5 10 9 10 11 13 9.5 8.5 9.5 10 .5 9.5 11 11 .5 13 .5 10 8 9 10 .5 9.5 11 10 .5 13 .5 9.67 8.17 9.33 41 10 .3 9.33 10 .7 11 41 6:19 6:29 6:39 6:47 6:56 7:05 7:16 7:25 7:36 7:46 10 9.5 8.5 9 11 9 10 10 10 10 9 9.5 10 .5 8.5 11 9 9.5 10 .5 8.5 9.5 10 .5 9 11 .5 12 9.83 10 8.67 9.33 38 10 .7 8.83 10 .8 10 .3 41 6:25 6:39 6:50 6:59 7:10 7:15 7:26 7:35 7:46 7:57 13 12 9 10 11 .5 9 11 11 14 11 8 11 11 9 12 10 14 11 9 12 11 8 11 10 13 .7 11 .3 8.67 11 45 11 .2 8.67 11 .3 10 .3 42 6:37 6:49 7:00 7:09 7:20 7:25 7:36 7:45 7:56 8:06 11 12 9 11 11 9 11 10 41 42 12 11 9 12 12 9 10 10 12 12 8 11 11 10 11 11 11 .7 11 .7 8.67 11 .3 43 11 .3 9.33 10 .7 10 .3 42 6:45 6:59 7:10 7:19 7:30 7:35 7:46 7:55 8:06 8:17 14 11 9 12 11 9 12 11 14 11 10 11 11 9 11 12 15 11 9 11 12 10 11 11 14 .3 11 9.33 11 .3 46 11 .3 9.33 11 .3 11 .3 43 6:57 7:09 7:20 7:29 7:40 7:45 7:56 8:05 8:16 8:26 8:46 12 11 9 11 10 9 11 10 13 10 8 11 45 43 11 8 10 11 11 11 9 12 11 9 11 11
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H E A D W A Y S H E E T L in e 9 6 IN EFF : S ep te m be r 15 , 200 7 M O NDA Y T HRU F R IDA Y HE AD W A Y W ITH 3-D A Y RUNNING TIME C HE C K S A D D E D D IR E C TIO N = N O R TH - S O U TH P M P E A K P E R IO D Libby Sand Pasco Pasco Pasco Rugby Avg Avg Proposed Proposed Rugby Pasco Pasco Pasco Sand Libby Avg Avg Proposed Proposed Wishrm Point Essex Havre Willis Circle Lib/Wsh Sand Pt Lib/Wsh Sand Pt Circle Willis Havre Essex Point Wishrm LVE.
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From page 77... ...
The tables below show a comparison of present versus proposed adjusted running times. On these tables, the start time of the fi rst trip with a change in running time is highlighted in gray to allow the reader to refer back to the original schedule.
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From page 78... ...
Schedule Building 3-48 SOUTHBOUND Current Runtimes Proposed Runtimes Period Beginning Wishram Sand Point Period Beginning Wishram Sand Point Ͱ:ͭͬ ͯͯ ͯͮ Ͱ:ͭͬ ͯͯ ͯͮ ͱ:ͮͬ ͯͳ ͯͳ ͱ:ͮͬ ͯͳ ͯͳ Ͳ:ͱͬ Ͱͮ Ͱͭ Ͳ:ͱͬ Ͱͮ Ͱͭ ͵:ͮͮ ͯͳ ͯͲ ͵:ͮͮ ͯͳ ͯͲ ͭͯ:ͯͱ ͯ͵ ͯʹ ͭͯ:ͯͱ Ͱͬ ͯ͵ ͭͱ:ͯͯ Ͱͯ Ͱͮ ͭͲ:ͮͬ Ͱͮ Ͱͭ ͭͲ:ͮͬ ͰͲ Ͱͱ ͭͳ:ͯͬ Ͱͬ ͯ͵ ͭͳ:ͯͬ Ͱͮ Ͱͭ ͭʹ:ͱͬ ͯͲ ͯͱ ͭʹ:ͱͬ ͯͳ ͯͲ ͮͭ:ͬͱ ͯͭ ͯͬ ͮͭ:ͬͱ ͯͭ ͯͬ Clearly, the southbound direction running time gets the biggest adjustment. In the PM peak four minutes will be added to both branches over the present allowances.
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From page 79... ...
Chapter 3. Schedule Building 3-49 Level ͮ.
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From page 80... ...
The example below tries unsuccessfully to fi t the new running times into the existing schedule. Several southbound trips (highlighted in gray)
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From page 81... ...
Choose the leaving times of these trips and highlight them in gray, as shown below. S C H E D U L E S H E E T - R e vis e d runn ing tim e s in o rig ina l sc he d ule Route 96 IN EFF: S eptem ber 15, 2007 M O NDAY THRU FRIDAY NO RTHB O UND S O UTHB O UND OUT Libby Sand Pasco Pasco Pasco Rugby Rugby Pasco Pasco Pasco Sand Libby IN BLK GAR Wishrm Point Essex Havre Willis Circle Circle Willis Havre Essex Point Wishrm GAR LVE.
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From page 82... ...
Schedule Building 3-52 S C HE D UL E S HE E T with trip s ne e d ing ne w tim e s hig hlig hte d R o u te 96 IN EF F : S ep tem be r 15 , 200 7 M O NDA Y T HRU F R IDA Y N O R TH B O UN D S O U TH B O UN D OUT Libby Sand Pasco Pasco Pasco Rugby Rugby Pasco Pasco Pasco Sand Libby IN GAR Wishrm Point Essex Havre Willis Circle Circle Willis Havre Essex Point Wishrm GAR LVE.
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From page 83... ...
S C HE D UL E S HE E T with ne w running tim e s Ro u te 96 IN EF F : M O NDAY T HRU F RIDAY NO RTHB O UND S O UTHB O UND OUT Libby Sand Pasco Pasco Pasco Rugby Rugby Pasco Pasco Pasco Sand Libby IN GAR Wishrm Point Essex Havre Willis Circle Circle Willis Havre Essex Point Wishrm GAR LVE.
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From page 84... ...
S C HE D UL E S HE E T with ne w runn ing tim e s and re vis e d s o uthb o und he ad ways R ou te 96 IN EFF : M O NDA Y T HRU F R IDA Y N O R TH B O UN D S O U TH B O UN D OUT Libby Sand Pasco Pasco Pasco Rugby Rugby Pasco Pasco Pasco Sand Libby IN GAR Wishrm Point Essex Havre Willis Circle Circle Willis Havre Essex Point Wishrm GAR LVE.
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From page 85... ...
Now the running time has been adjusted in both directions, and new southbound trips have been added. Study your progress so far.
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From page 86... ...
Schedule Building 3-56 S C HE D UL E S HE E T with ne w runn ing tim e s and "f lip p e d " s o uthb o und trip s R o u te 9 6 IN EF F : M O N D A Y T H R U F R ID A Y N O R TH B O U N D S O U TH B O U N D OUT Libby Sand Pasco Pasco Pasco Rugby Rugby Pasco Pasco Pasco Sand Libby IN GAR Wishrm Point Essex Havre Willis Circle Circle Willis Havre Essex Point Wishrm GAR LVE.
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From page 87... ...
SC HED ULE SHE ET with ad jus te d running tim e and headways R o u te 96 IN EF F : M O NDA Y T HRU F R IDA Y N O R TH B O UN D S O U TH B O UN D OUT Libby Sand Pasco Pasco Pasco Rugby Rugby Pasco Pasco Pasco Sand Libby IN GAR Wishrm Point Essex Havre Willis Circle Circle Willis Havre Essex Point Wishrm GAR LVE.
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From page 88... ...
The reason that this schedule works is that the eight-minute headway is in place for only about half the peak round trip cycle. Some buses will not be making a full cycle during the time when the headways are tightest and running time longest and therefore will not require the full ʹ͵ minutes allocated to a round-trip.
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From page 89... ...
S C HE D UL E S HE E T with ad jus te d running tim e and he ad ways Ro u te 96 IN EF F : M O NDAY T HRU F RIDAY P art 1 NO RTHB O UND S O UTHB O UND OUT Libby Sand Pasco Pasco Pasco Rugby Rugby Pasco Pasco Pasco Sand Libby IN BLK GAR Wishrm Point Essex Havre Willis Circle Circle Willis Havre Essex Point Wishrm GAR LVE.
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From page 90... ...
Schedule Building 3-60 S C HE D UL E S HE E T with ad jus te d running tim e and he ad ways Ro u te 96 IN EF F : M O NDAY T HRU F RIDAY P art 2 NO RTHB O UND S O UTHB O UND OUT Libby Sand Pasco Pasco Pasco Rugby Rugby Pasco Pasco Pasco Sand Libby IN BLK GAR Wishrm Point Essex Havre Willis Circle Circle Willis Havre Essex Point Wishrm GAR LVE.
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From page 91... ...
Advanced Schedule Building To summarize this section: we took the information from the traffi c checks and made a real world example schedule change that incorporated both increased running time and the need for an additional trip. We did it in the least intrusive way, disturbing the riding habits of the patrons of this route to the least extent possible.
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From page 92... ...
Level ͯ. Advanced Schedule BuildingChapter 3.
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From page 93... ...
In addition a number of transit systems have undertaken studies of their own as to how best approach running times methodology. The survey of transit operators, conducted as part of this project, revealed that taking averages of running time observations continues to be the most common way of setting running times on a route or route segment.
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From page 94... ...
What the scheduler should be moving towards when developing running times is the point where effi ciencies are maximized and operating speeds high, but not to the point that degrades system reliability -- represented by an area within the shaded area on the graph. This is, in theory, the point at which running times are "optimized," and this point exists for each running time problem.
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From page 95... ...
Provision of suffi cient layover time is the most obvious means to control for diff erences among operators. The interaction between running times and layover will be discussed in more detail below.
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From page 96... ...
One approach frequently used to avoid running hot is to schedule very tightly on the early segments of a route and provide more generous running time on later segments. This makes it almost impossible to run hot if an operator leaves on time, and yet gives the operator confi dence that s/he will be able to take all of the scheduled layover at the end of the trip.
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From page 97... ...
The best type of running time data is that which provides elapsed running time, both for end-to-end and trip segments. Using this type of data the scheduler can analyze and develop running times based on actual running time observations.
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From page 98... ...
As discussed above, the strategies of setting minimal running times along early segments of a route and either more generous running times in later segments or more generous layover time are used by many agencies to provide adequate running time while minimizing early departures at time points. If either of these approaches is used, the amount of time taken from initial route segments should be small, leaving a "tight" running time rather than an impossible one.
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From page 99... ...
One survey respondent reported setting running times on a route so that: Ͳͱ% of all trips fi nish in time for the operator to take the minimum layover. As an example, if the scheduled running time of a trip is ͱͭ minutes with nine minutes of scheduled layover and a contract stipulation of ͭͬ% minimum layover, then Ͳͱ% of trips are completed no more than three minutes late (to allow for the minimum six minutes layover time)
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From page 100... ...
Schedule Building 3-70 TCRP Report ͭͭͯ discusses how AVL-APC data can be used to set running times at the route and segment level.ͮ Route-level approaches include percentile-based strategies such as: Setting running time at the ʹͱth percentile of observed running times (in other words, running times are set so that ʹͱ% of all trips fi nish on time)
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From page 101... ...
After a few sign-ups, the eff ect on schedule adherence of setting running times using X percentile will be apparent, at which point the scheduler may conclude that this approach works or may experiment with use of a diff erent percentile. The percentile approach is just one of many statistical means of developing running times.
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From page 102... ...
The availability of larger volumes of data does not necessarily call for changes in traditional means of establishing running times. It does, however, allow more sophisticated models of running times analysis and development to be undertaken.
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From page 103... ...
One possible blending scheme is shown below. intertiming The process of scheduling trips of two or more routes that share a common segment in a manner that evenly spaces the trips over the common segment.
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From page 104... ...
The point where the express vehicle passes the local vehicle is of less importance on bus routes. For rail or trolley coach routes without facilities for passing, the scheduler will have to be innovative, starting the express trip just ahead of the local and applying running time (and possibly a headway adjustment)
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From page 105... ...
The discussions alluded to but did not directly address the important interaction between running times and layover time. In "optimizing" running times it is wise to consider layover requirements and implications, in order to prepare the "best" schedule.
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From page 106... ...
The existing running time is shown as a line that changes across the day as the running time periods change. ExisƟng Run Time Same trip varying over several days ExisƟng Run Time In this example, there is little chance for the scheduler to develop any proposed running times that will result in a high level of on-time performance.
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From page 107... ...
An example using charts & data tables from the Hastus ATP system with a combination of graphical data views, statistical approaches, and scheduler experience can demonstrate how to develop a solution. The chart below shows the same data set of observed running times.
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From page 108... ...
Schedule Building 3-78 The scheduler is faced with a diffi cult assignment. Clearly there is major running time variability, and setting any run time at any level will not necessarily satisfy the aims described previously.
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From page 109... ...
The fi gure & table below show recovery plus layover times set at around the ͵ͯrd percentile. That is, if running time plus layover between ͮ PM and Ͳ PM is set at Ͱͭ minutes, ͵ͯ% of next trips will depart on time.
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From page 110... ...
In an example like this one, layover is used as a means of dealing with run time variability, regardless of the level of running time being set, because for running time data with high variability, the scheduled running times cannot achieve the necessary reliability levels. In this example the running time could set at a much lower level, let's say around the average of ͯͯ minutes.
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From page 111... ...
In cases where running time variability is high enough that a range of running times can be applied with similar outcomes to the same data set, adding additional running time periods is not worth the complexity, as estimating run times to such a level of precision is optimistic. The recommendation is not to overuse running time periods.
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From page 112... ...
Let's start with a simple example -- one route with several running time transitions during the AM Peak. The run times are set out below.
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From page 113... ...
Conversely, as running times are reduced at the end of the peak a short nine-minute headway occurs at Point E Such schedules can result in unstable operation and probably do not refl ect "real-life" operating conditions.
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From page 114... ...
This type of transitioning recognizes that running times tend to change less in a tidal movement along a route, and more across the entire route at the same time. The running time periods apply not to the start time of the trip (as in traditional methods)
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From page 115... ...
Running Time Myths To summarize this discussion, some common scheduling myths are noted below: Running time problems are all scheduling problems. High variability of running times indicates a strong possibility that there are other factors at work and scheduling solutions alone cannot resolve the issue.
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From page 116... ...
Where longer layover is suggested for longer routes it is primarily related to operator rest time, not necessarily to run time variability. Setting running times is a statistical process.
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From page 117... ...
Chapter 3. Schedule Building 3-87 Level ͯ.
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Key Terms
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