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OCR for page 355
Rail Scheduling Chapter 7. Rail Scheduling
7.1 Rail Scheduling
Rail scheduling differs from bus scheduling in a number of ways, some subtle and some more
yard wide ranging. At its most basic, rail service must follow a fixed guideway all the way from the
The rail equivalent of "garage," the
storage facility, or "yard," to the beginning of the route. There is much less flexibility in choos-
place where rail vehicles are stored ing pull-in and pull-out locations, as the guideway dictates how the route will operate. Often,
and maintained. rail lines are scheduled by separate scheduling personnel who are very familiar with rail opera-
tions. This helps ensure that all local work rules, conventions, and practices (many of which are
not listed in the union contract) are followed. There is also one other major difference between
rail and bus: when properly done, schedule makers/operations planners will be consulted by
the engineers designing either a new facility or a reconstructed terminal early in the design
process, and will ask--both operations and operations planners/schedulers--what a preferred
terminal layout/track arrangement might be, space and budget permitting.
There are almost as many variations within rail scheduling as there are between rail and bus
scheduling. Many of these variations are tied to the type of rail operation being scheduled.
High platform rapid transit lines, often referred to as "Heavy Rail," use a different approach
from light rail or surface streetcar lines. Commuter rail is different altogether. Even among
heavy rail operators, each approach is somewhat unique to the respective system. Invariably,
though, many of these operational differences are at the terminal and the system's approach
is a response to the civil/track design of the particular terminal. This is why active participation
in terminal design is an important role for the schedule department to play. Judicious capital
investment at the beginning can pay operating budget dividends, or simply provide more reli-
able, quality service to customers.
Much has been written elsewhere about what constitutes a "heavy" versus "light" rail system
or even a streetcar line, as some rail systems have the characteristics of each. For our purpos-
es, we define heavy rail as:
· Operating on segregated rights-of-way, often on elevated structures or in subway.
· Boarding from high platforms.
· Serving complex stations where passengers cannot cross tracks, but must go up (or
down), over or under to reach other platforms.
· Running as many as ten cars in a single train, under the control of a train operator and
(on some systems) a conductor.
· The rail cars themselves in a heavy rail system will have operable end doors, which per-
mit passage from car-to-car in a multi-car trainset. (Many systems may lock these doors
to prevent rider passage from car to car for security reasons, but the doors, nonethe-
less, are operable and an integral part of the car body's design.)
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Chapter 7. Rail Scheduling Rail Scheduling
Light rail, on the other hand is an upgraded version of streetcar lines, sometimes on segregat- consist
ed rights-of-way but often operating in the street in mixed traffic for at least part of their route. (pronounced CON-sist) A term that
Station designs are usually simple, with low platforms and the ability to walk across tracks to refers collectively to the rail cars
enter or exit the station. "Trains" are often one car long, and when longer (e.g., two or three comprising a train, i.e., a four car
cars) passengers cannot cross from car-to-car on-board the train as there aren't any doors at train is a four car consist.
the car ends to pass through. Therefore, scheduling for light rail comes closer to bus scheduling
in approach. drop-back
To keep the size of this chapter manageable and to impart as much useful information as pos- A technique where the operator
sible about rail scheduling techniques, we will focus on light rail, a fast-growing mode in North or train crew gets off an arriving
America, and add comments where appropriate on the differences for other rail modes. vehicle at a terminal, takes layover,
and assumes operation of the next
Ways in which rail scheduling differs from bus scheduling: vehicle to arrive. Most common
on frequent rail lines where close
· Pull-on and pull-off trips must follow the rails and are usually scheduled into the timeta- headways do not allow sufficient
ble so that they are accounted for. This is especially important if there is a large amount layover time for the train crew, this
of single track on the rail system. technique is also used for special
· The scheduler must be familiar with the track structure: the layout of junctions, loca- events to maximize the number of
tions of crossovers, number of tracks at each terminal station or intermediate stations trains in service. If service is very
where train turnbacks may be scheduled and whether crossovers are located in front of frequent, the train crew may not
or behind the platforms at the terminal station. He/she should also have a basic famil- board the next train but instead the
iarity with the signal system and such details as how close a headway the system will train after that; this is called a "dou-
support. There is no reason to schedule trains one minute apart if the signal system will ble drop-back." Some agencies
not allow it. It has been learned through experience that most signal systems, wayside use the term "fall-back" instead.
and otherwise, cannot handle headways closer than every two minutes for sustained
periods (more than minutes). The primary reason for this is station dwell activity
(boarding and alighting) that itself approaches--or exceeds--two minutes. There are
other reasons as well, but a discussion of this topic (practical rail headways) is beyond
the scope of this manual.
· Rail schedules often have one time point for each station, resulting in more timepoints
than are found on a typical bus schedule. This makes computerized scheduling that
much more appealing.
· All heavy rail and most light rail involve scheduling trains, which are mostly made up
of more than one car. (The number of cars in a train is called a consist (pronounced
CON-sist), i.e., a four car train is a four car consist.) On light rail systems especially and
on some heavy rail systems, cars will be added and cut from the train as the day pro-
1 Recall that frequency is the inverse of headway: a headway of 2 minutes is equivalent to a frequency of one train every two minutes,
or 30 trains per hour.
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Rail Scheduling Chapter 7. Rail Scheduling
meet gresses. These changes are typically tracked by the scheduler who keeps up with the car
Two trains, on two different tracks count, much as he/she tracks the bus count on a bus schedule.
(in single-track operation, one train · Rail systems often make widespread use of "drop-backs" at the ends of their routes. A
is on a passing siding), converging drop-back occurs when the arriving "crew" (a crew can be just one person, the train op-
at the same location.
erator, or also the conductor) gets off the train and waits one or more departing trains
before once again assuming operation of a train. This invariably means that there are
yard balancing more active crews in the cycle than active consists.
The process of ensuring that the · Rail lines are more likely to have fewer running time changes. In some cases, the run-
number of train cars pulling into ning time is the same all day. In fact, on systems with a lot of single track with pass-
a specific yard at the end of the ing sidings, a single running time is a necessity in order to assure that meets occur at
service day equals the number that regular intervals. On sections operating in mixed traffic, running times are set using the
pulled out at the beginning of the same procedures described earlier for bus routes, and may change throughout the day.
service day. On rail lines served · Longer-length rail lines will often have yards on both ends of the line in order to cut
by more than one yard, the same down on the amount of time and mileage for nonessential trips that just serve to get
vehicles do not necessarily return out of or into the yard. In many cases trains are put into service heading to the nearest
to the same yard. Only the count in terminal and later pulled in from the nearest terminal, which may not be the one from
each yard must be the same at the which it went into service. For this reason, schedulers have to keep track of yard counts
end of the day as the beginning. as well as car and train counts. The schedule should always get the same number of
cars back to each respective yard as it provided at the beginning of the operating day.
banging out Otherwise, Maintenance personnel may have to make expensive yard deadhead moves
the schedule in the middle of the night. This attention to yard count is called "Yard Balancing."
A rail scheduling term for the · On systems where routes merge and diverge (as contrasted with routes that are self-
process of scheduling trips on lines contained), special care must be taken to schedule trains so they flawlessly intersperse
that share a common segment in with the other route's trains. To leave this to chance is to experience delays with trains
such a way that spaces the trains waiting out red signals while the other train crosses in front of it or pulls ahead of it. On
on the common segment. If the one large system, the process of making sure that schedules for different subway lines
spaces on the common segment merge properly is known as "banging out" the schedule and this follows the writing of
are evenly apart this is the rail the individual timetables.
equivalent of "intertiming."
2 For the most part, unlike buses which are assigned to a particular depot for maintenance purposes--and need to go "home" in order
to be maintained--rail cars are assigned to a line (or sometimes shared between lines). Rail maintenance is line-based, and it is the
maintenance department that determines how, when, and where--working with Transportation (and in some places, with Schedul-
ing)--individual cars on a line will be maintained.
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Chapter 7. Rail Scheduling Rail Scheduling
Despite these differences, scheduling of rail service bears a lot of similarities to bus scheduling. train block
This is particularly true in the following ways: The series of trips operated by each
· Scheduling rail service is still a matter of making supply available to meet demand train from the time it pulls out to the
based on rider information and service standards at a maximum load point. time it pulls in. A complete block
· Trips are scheduled the same once the headway by time of day is known. It is an obvi- includes a pull-out trip from the yard
ous point (worth repeating nonetheless) that differing services running on the same followed by one or (usually) more
track must have the same headway or combinations of differing headways that allow revenue trips and concluding with a
sufficient clear track between trains. As mentioned above, practical operation and sig- pull-in trip back to the yard.
nal systems rarely allow for trains to be closer than two minutes apart. On most heavy
rail lines and light rail lines that run on private right-of-way, this rule is enforced by cab crew block
signal systems, which will automatically brake the train if one gets too close to the one The series of trips operated by each
ahead. train crew from pull-out to pull-in.
Under what circumstances would differing headways be appealing? The most com- The crew block will differ from the
mon situation is when every other trip on a line turns short of the normal route end. train block if drop-backs are sched-
Giving the short-turn trips a wider headway will often even out ridership levels between uled for the crews.
through and short turn vehicles. For example, if a line has a . -minute headway, the
trips could be arranged to operate and . Under a and headway, the train from the
more distant terminal would leave, followed by a short-line trip nine minutes later, and
then followed by a long (more distant terminal) trip six minutes later. With more pas-
senger boardings within the common segment likely to be on the short trip (assuming
random arrival at the station), this mix would even out loads.
· Headways usually differ by time of day and service ramps up and down, into and out
of the peaks just as it does for bus schedules. That said, there is probably greater use
of clockface headways on light rail lines (e.g., same times past the hour seven days a
week) than on buses.
· Rail trips are blocked the same as bus trips. The resulting blocks are often referred to
as "train blocks" to differentiate them from "crew blocks" which may not follow the
same train all day, particularly if a drop-back is scheduled for the crews at one or both
ends of the route.
With that in mind, the novice scheduler should not be afraid to try his or her hand with a rail
schedule. Most of what you have learned to this point will hold true through the process of
building trips and blocking them into "train blocks."
Route -Light Rail is a typical schedule for a rail line operating from the west side of a city,
through the downtown area to the east side. Some of the line is on streets in mixed or segre-
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Rail Scheduling Chapter 7. Rail Scheduling
gated traffic, mostly in the downtown area, while much of the outer portion of line is on its own
right-of-way.
While this background information should be helpful in giving the scheduler a mental picture of
the line, its relevance to producing a schedule is that the schedule will be kept relatively simple,
as rail schedules go, and many of the steps and techniques learned earlier will be followed, with
emphasis on the new tasks.
The service pattern for Route calls for a mostly uniform -minute service for peak hours
and minutes during the midday period. During these times, a short-turn service is inter-
spersed between these trains to provide double the service. Turnback locations are at both the
west (Dekalb Station) and east (Soto Station) sides of the line as shown in the Route Light
Rail Track Diagram below. During early morning and evenings, these short turns do not run,
and a -minute headway is provided end to end except for the earliest and latest trips of the
day. All segments of this line are double track, so keeping a watchful eye on where trains meet
is not a factor in this example.
Be aware of the number
Tip
of trains that could be
at a given terminal at the same
time. If two tracks are available at
the terminal, the train on track one
should depart at least two minutes
before the scheduled arrival of the
next train to use track one. This
translates to a maximum layover at
One important factor is the number of trains that could be at either end terminal at one time.
a terminal equal to: Since the end stations feature two tracks with a middle passenger platform (a somewhat
standard arrangement--for further discussion of terminal design and its relationship to sched-
HEADWAY (in minutes) * NO. OF TRACKS
uling, see Terminal Design and Scheduling Efficiency at the end of this chapter), the rule is to
AT TERMINAL STATION 2 have the first train depart well before (at least two minutes is a good time "cushion") the third
train is scheduled into the terminal. This will place limits on the amount of layover that can be
scheduled. With -minute headways as the most frequent service level at end terminals, this
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Chapter 7. Rail Scheduling Rail Scheduling
will not be a problem in our example. Calculating double the headway (representing the avail- cycle time
ability of two tracks) minus the two minutes (safety and reliability factor), layover could extend Sum of the round trip running time
to as much as minutes, which is well beyond any reasonable amount we would want to give. plus layover time. This is also
known as "round-trip cycle time."
As is often the case with actual light rail lines of this cross-city design, storage yards are provid-
ed at or near each end of the line on our example schedule. The West Yard is located adjacent to
the West Station. On the east end another yard is located near the Soto Station. When block-
ing, the two yards will add a level of complication to the effort, which we will see later.
Calculating Two Round-trip Cycles
As in bus scheduling, we start with our round-trip cycle calculation, but in this example we have
a complication introduced by the short-turn operation. The way to address this is to look at the
full route cycle first. It always has to work before working on the short cycle. So, work on the
long cycle first, and then address the short cycle.
For the base period (which includes early morning and evening) the round-trip running time is
+ = , before layover time is added. The headway on the long cycle is minutes in the
early morning and evening periods (when all trains operate the entire length of the line) and
minutes in the midday period.
Consider the midday period first. A -minute headway yields potential round-trip cycle times
of , , and . The minutes of round-trip running time would fit into a -minute
cycle, leaving eight minutes per round trip for layover. Although that number is below the %
usually considered as minimum, we could opt to turn the trains in minutes and stretch the
crews by scheduling them to drop-back one train at one of the terminals. This would save a
two-car train from the schedule. Viewed from a numbers standpoint, there would be five trains
and six crews operating on the long cycle.
On the other hand, drop-backs have their disadvantages. They almost always require some
supervision; they can promote conditions where a train sits at a stop or platform without
boarding passengers or which boards passengers but has no crew on board. Supervision can
overcome some drawbacks, but if possible, it is almost always preferable to schedule enough
layover in the cycle and leave crews on their trains.
Therefore, in our example above we go for the -minute cycle time and schedule six trains to
the full route trips. If we build trips with leaving times starting on the hour from both terminals,
the layover is evenly distributed with minutes available at each end. Sample roundtrips
are shown below, confirming that the layover times work as expected and that six blocks are
needed.
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Rail Scheduling Chapter 7. Rail Scheduling
HE A D W A Y S HE E T
L in e 100 - L ig h t R a il IN EF F : F a ll 200 8
M O N D A Y T H R U F R ID A Y
D IR E C TIO N = E A S T-W E S T
A B C D E F G G F E D C B A
WEST DEKALB LORAIN DNTWN MIDDLE SOTO EAST EAST SOTO MIDDLE DNTWN LORAIN DEKALB WEST
BLOCK TERM STA STA TERM BURG STA TERM LVE. BLOCK TERM STA BURG TERM STA STA TERM LVE.
1 9 :2 0 10 :0 6 10 :2 0 1 10 :2 0 11 :0 6 11 :2 0
2 9 :4 0 10 :2 6 10 :4 0 2 10 :4 0 11 :2 6 11 :4 0
3 10 :0 0 10 :4 6 11 :0 0 3 11 :0 0 11 :4 6 12 :0 0
4 10 :2 0 11 :0 6 11 :2 0 4 11 :2 0 12 :0 6 12 :2 0
5 10 :4 0 11 :2 6 11 :4 0 5 11 :4 0 12 :2 6 12 :4 0
6 11 :0 0 11 :4 6 12 :0 0 6 12 :0 0 12 :4 6 13 :0 0
1 11 :2 0 12 :0 6 12 :2 0 1 12 :2 0 13 :0 6 13 :2 0
We could follow this same cycle for early and late trips using eight trains for the -minute ser-
vice. This is one more train than we could get away with in the cycle. A -minute cycle would
yield minutes of layover, which would amply meet our %, but would affect our ability to
leave on the hour and at easily remembered times (: , ; , : ) from both terminals. While it
might be desirable to give up on these departure times to produce significant savings, the du-
ration of the early and late trips is not long enough to produce significant savings of vehicle and
platform hours. Sample roundtrips in the evening are shown below.
HE A D W A Y S HE E T
L in e 100 - L ig h t R a il IN EF F : F a ll 200 8
M O N D A Y T H R U F R ID A Y
D IR E C TIO N = E A S T-W E S T
A B C D E F G G F E D C B A
WEST DEKALB LORAIN DNTWN MIDDLE SOTO EAST EAST SOTO MIDDLE DNTWN LORAIN DEKALB WEST
BLOCK TERM STA STA TERM BURG STA TERM LVE. BLOCK TERM STA BURG TERM STA STA TERM LVE.
1 19 :0 0 19 :4 6 20 :0 0 1 20 :0 0 20 :4 6 21 :0 0
2 19 :1 5 20 :0 1 20 :1 5 2 20 :1 5 21 :0 1 21 :1 5
3 19 :3 0 20 :1 6 20 :3 0 3 20 :3 0 21 :1 6 21 :3 0
4 19 :4 5 20 :3 1 20 :4 5 4 20 :4 5 21 :3 1 21 :4 5
5 20 :0 0 20 :4 6 21 :0 0 5 21 :0 0 21 :4 6 22 :0 0
6 20 :1 5 21 :0 1 21 :1 5 6 21 :1 5 22 :0 1 22 :1 5
7 20 :3 0 21 :1 6 21 :3 0 7 21 :3 0 22 :1 6 22 :3 0
8 20 :4 5 21 :3 1 21 :4 5 8 21 :4 5 22 :3 1 22 :4 5
1 21 :0 0 21 :4 6 22 :0 0 1 22 :0 0 22 :4 6 23 :0 0
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Chapter 7. Rail Scheduling Rail Scheduling
Now we look at peak cycles for the long trips. The round-trip running time in the peak is +
= , which continues to work within our -minute cycle. It produces minutes of layover
at each terminal. This is more than enough so that drop-backs do not need to be considered.
Sample long trips for the peak are:
HE A D W A Y S HE E T
L in e 100 - L ig h t R a il IN EF F : F a ll 200 8
M O N D A Y T H R U F R ID A Y
D IR E C TIO N = E A S T-W E S T
A B C D E F G G F E D C B A
WEST DEKALB LORAIN DNTWN MIDDLE SOTO EAST EAST SOTO MIDDLE DNTWN LORAIN DEKALB WEST
BLOCK TERM STA STA TERM BURG STA TERM LVE. BLOCK TERM STA BURG TERM STA STA TERM LVE.
1 6 :0 0 6 :5 0 7 :0 0 1 7 :0 0 7 :5 0 8 :0 0
2 6 :1 5 7 :0 5 7 :1 5 2 7 :1 5 8 :0 5 8 :1 5
3 6 :3 0 7 :2 0 7 :3 0 3 7 :3 0 8 :2 0 8 :3 0
4 6 :4 5 7 :3 5 7 :4 5 4 7 :4 5 8 :3 5 8 :4 5
5 7 :0 0 7 :5 0 8 :0 0 5 8 :0 0 8 :5 0 9 :0 0
6 7 :1 5 8 :0 5 8 :1 5 6 8 :1 5 9 :0 5 9 :2 0
7 7 :3 0 8 :2 0 8 :3 0 7 8 :3 0 9 :2 0
8 7 :4 5 8 :3 5 8 :4 5 8 8 :4 5 9 :3 5 9 :4 0
1 8 :0 0 8 :5 0 9 :0 0 1 9 :0 0 9 :5 0 10 :0 0
Once we are satisfied with the long trips, we look at the short cycle. Round-trip running time
on the short cycle for the base is + = . A -minute headway yields cycles of , , and
. is too short. would give us minutes to divide between both turnback terminals.
We write a few trips exactly fitting in between the long trips and note that they give us eight
minutes at Soto Station on the east and minutes at Dekalb Station on the west. It seems
ideal for our purposes.
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Rail Scheduling Chapter 7. Rail Scheduling
In the example below, letters are used to denote short blocks to make it easier to see how they
fit into the schedule (this would not be done in a typical blocking scheme). Also, the introduc-
tion of the short-turn trips means that the blocks no longer line up evenly across each row
when trips are sorted by time at common stations.
HE A D W A Y S HE E T
L in e 100 - L ig h t R a il IN EF F : F a ll 200 8
M O N D A Y T H R U F R ID A Y
D IR E C TIO N = E A S T-W E S T
A B C D E F G G F E D C B A
WEST DEKALB LORAIN DNTWN MIDDLE SOTO EAST EAST SOTO MIDDLE DNTWN LORAIN DEKALB WEST
BLOCK TERM STA STA TERM BURG STA TERM LVE. BLOCK TERM STA BURG TERM STA STA TERM LVE.
A 10 :1 7 10 :4 8 10 :5 8
1 9 :2 0 9 :2 8 9 :5 9 10 :0 6 10 :2 0 1 10 :2 0 10 :2 7 10 :5 8 11 :0 6 11 :2 0
A 9 :3 8 10 :0 9 10 :1 7 B 10 :3 7 11 :0 8 11 :1 8
2 9 :4 0 9 :4 8 10 :1 9 10 :2 6 10 :4 0 2 10 :4 0 10 :4 7 11 :1 8 11 :2 6 11 :4 0
B 9 :5 8 10 :2 9 10 :3 7 C 10 :5 7 11 :2 8 11 :3 8
3 10 :0 0 10 :0 8 10 :3 9 10 :4 6 11 :0 0 3 11 :0 0 11 :0 7 11 :3 8 11 :4 6 12 :0 0
C 10 :1 8 10 :4 9 10 :5 7 D 11 :1 7 11 :4 8 11 :5 8
4 10 :2 0 10 :2 8 10 :5 9 11 :0 6 11 :2 0 4 11 :2 0 11 :2 7 11 :5 8 12 :0 6 12 :2 0
Finally, the short trips in the peak cycle require a decision: where to place them in between the
long trips--either seven or eight minutes after the former. While one minute may not seem like
much, the general rule is to give the greater headway to the short trip. In fact, if loads between
the two trip patterns become unbalanced, we might want to consider a and split, with the
short trip gaining the wider headway (i.e., leaving nine minutes after the long trip). In this case
a simple - should work fine.
The short round-trip running time in the peak periods is + = . At a -minute headway,
the first cycle time to consider is , which experience tells us is too little layover and would
produce an even headway in only one direction. We can assure ourselves of our hunch by build-
ing some trips that meet this layover constraint.
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Chapter 7. Rail Scheduling Rail Scheduling
HE A D W A Y S HE E T
L in e 100 - L ig h t R a il IN EF F : F a ll 200 8
M O N D A Y T H R U F R ID A Y
D IR E C TIO N = E A S T-W E S T
A B C D E F G G F E D C B A
WEST DEKALB LORAIN DNTWN MIDDLE SOTO EAST EAST SOTO MIDDLE DNTWN LORAIN DEKALB WEST
BLOCK TERM STA STA TERM BURG STA TERM LVE. BLOCK TERM STA BURG TERM STA STA TERM LVE.
A 6 :5 5 7 :2 8 7 :3 2
1 6 :0 0 6 :0 9 6 :4 2 6 :5 0 7 :0 0 1 7 :0 0 7 :0 8 7 :4 1 7 :5 0 8 :0 0
A 6 :1 7 6 :5 0 6 :5 5 B 7 :1 0 7 :4 3 7 :4 7
2 6 :1 5 6 :2 4 6 :5 7 7 :0 5 7 :1 5 2 7 :1 5 7 :2 3 7 :5 6 8 :0 5 8 :1 5
B 6 :3 2 7 :0 5 7 :1 0 C 7 :2 5 7 :5 8 8 :0 2
3 6 :3 0 6 :3 9 7 :1 2 7 :2 0 7 :3 0 3 7 :3 0 7 :3 8 8 :1 1 8 :2 0 8 :3 0
C 6 :4 7 7 :2 0 7 :2 5 D 7 :4 0 8 :1 3 8 :1 7
Sure enough, in the other direction from the even trips, short trips are almost on top of the
long trips, as highlighted. So, we settle for the next multiple of , which is . This gives us
minutes to be divided between the two turnback terminals. We build some sample trips eight
minutes after the through trips in each direction and see that the layover falls out as min-
utes at Soto and at Dekalb. This works well.
HE A D W A Y S HE E T
L in e 100 - L ig h t R a il IN EF F : F a ll 200 8
M O N D A Y T H R U F R ID A Y
D IR E C TIO N = E A S T-W E S T
A B C D E F G G F E D C B A
WEST DEKALB LORAIN DNTWN MIDDLE SOTO EAST EAST SOTO MIDDLE DNTWN LORAIN DEKALB WEST
BLOCK TERM STA STA TERM BURG STA TERM LVE. BLOCK TERM STA BURG TERM STA STA TERM LVE.
A 7 :0 1 7 :3 4 7 :4 7
1 6 :0 0 6 :0 9 6 :4 2 6 :5 0 7 :0 0 1 7 :0 0 7 :0 8 7 :4 1 7 :5 0 8 :0 0
A 6 :1 7 6 :5 0 7 :0 1 B 7 :1 6 7 :4 9 8 :0 2
2 6 :1 5 6 :2 4 6 :5 7 7 :0 5 7 :1 5 2 7 :1 5 7 :2 3 7 :5 6 8 :0 5 8 :1 5
B 6 :3 2 7 :0 5 7 :1 6 C 7 :3 1 8 :0 4 8 :1 7
3 6 :3 0 6 :3 9 7 :1 2 7 :2 0 7 :3 0 3 7 :3 0 7 :3 8 8 :1 1 8 :2 0 8 :3 0
C 6 :4 7 7 :2 0 7 :3 1 D 7 :4 6 8 :1 9 8 :3 2
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Rail Scheduling Chapter 7. Rail Scheduling
Building the Trips
So far, this is looking very much like the preparation of a bus schedule, other than thoughts we
have considered regarding layover strategy. The schedule is somewhat formulaic in that we
have tried to stay to even, hour-based leaving times from terminals during most times of the
day ( ) because we could without undue extra cost and ( ) as a marketing point for the "conve-
nience" of the light rail service.
We can start building trips now that we have our cycles in mind. The only other piece of infor-
mation we need is the span of service and times for running each headway and service pattern.
Those instructions are as follows:
Route Light Rail
Service Plan
Span of Service : AM until midnight
minutes : - A, - Mid
Early AM/Late PM headways
min, - A, - P long only
Peak headways / min, - A, - P long, short
Base headways min, A- P, long, short
To be simple, start trips from each direction at : AM and build onward from there. If you are
building trips using either a spreadsheet or a scheduling package, you want to build the long
trips first, then go back and insert the short trips. Note that the Schedule Sheet is divided in
two with each direction having its own side independent of the other. The reason for this is the
short trips, which do not line up across the page as their cycle is two trains shorter.
Keep in mind that you have variable running time on this schedule. Use the Peak running times
during the times that have been designated above as Peak for headway purposes. The tran-
sition to peak headway and running times can be scheduled to occur at the same time. You
might want to do some running time smoothing after you construct your trips, since the com-
bination of the two changes does produce a noticeable gap in the headway. We have shaded
the trips where we manually "smoothed" the running time transition in order to minimize the
gaps.
Once you finish, you should have a schedule that looks approximately like our example, again,
not much different than a bus schedule at this point. The next step is to block the schedule.
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On the west end, it makes sense to pull out of West Yard to West Terminal and begin service
there. We take these short trips and extend them backward one time point. This is shown on
callout C in the above example. We make the same adjustment in reverse for pull-ins. When
calculating mileage, the scheduler needs to keep in mind these "half-long" trips will have a dif-
ferent pattern and mileage. These kinds of decisions show you the nuances of difference you
face in doing rail scheduling.
We should note that the East Yard trains' pull-out and pull-in times on the Schedule Sheet
are shown in italic. That will help us later when we resolve the yard count. We did not make a
distinction in the block numbering in this case. We could have, numbering all East Yard blocks
from, say, up. The numbering used on the blocks is standard to the way described in earlier
chapters. We put the all day blocks in order at the start of the base period (they don't stay in
order because of the shorter cycle of the short trips), then number the four AM blocks above
these, then the four PM blocks. So we ultimately have blocks numbered from to .
Yard Balancing
We build our Train Block Summary in the spreadsheet, just as we did in the bus example. In
this case, the East Yard pull-outs and pull-ins are shaded so they are easy to count. Some prior
planning and a largely symmetrical schedule have given us the same number of final pull-ins
to each yard as we had pull-outs at the start. In fact, the number of trains from each yard is the
same--nine. If we had an imbalance, we would have to establish one or more trips to rectify
the situation. These yard balancing trips could be in service or deadhead, before or after service
hours. In any event, such trips are wasteful, using mileage and hours that do not benefit the
rider. If such trips are needed, it is better to schedule the trip at a time when it can be in-ser-
vice. The least intrusive way would be to extend an existing pull-in trip across the route to the
other yard.
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T R AIN B LO C K S U M M AR Y
OUT IN VE H. VE H.
TR A IN TIM E TIM E H O UR S M IL E S
1 4:45 1:02 20 : 1 7
2 6:21 19 : 2 2 13 : 0 1
3 5:00 23 : 1 7 18 : 1 7
4 5:58 19 : 3 7 13 : 3 9
5 4:20 23 : 4 7 19 : 2 7
6 5:50 19 : 3 4 13 : 4 4
7 4:50 0:56 20 : 0 6
8 6:06 19 : 4 9 13 : 4 3
9 5:05 23 : 1 1 18 : 0 6
10 5:35 23 : 4 1 18 : 0 6
11 5:30 9:53 4:23
12 5:43 9:40 3:57
13 4:15 9:30 5:15
14 6:13 9:38 3:25
15 15 : 1 2 24 : 2 6 9:14
16 15 : 1 3 19 : 0 7 3:54
17 15 : 2 0 24 : 4 2 9:22
18 15 : 2 1 19 : 2 2 4:01
TO TA L 211 : 5 7
As an example, if we needed one more pull-in to the West Yard, we might consider taking
block , scheduled on a short pull-in trip leaving East Terminal at : PM (highlighted below
in gray), and extending it to West Terminal. We would make it the : PM trip, which would
effectively extend the -minute service one interval later westbound. It would add platform
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time to be sure, but it would do some useful work for the time. It is better still to plan the head-
way and transition times, as we have throughout this schedule, to eliminate yard balancing
trips entirely whenever possible. HEA D W A Y S HEE T
L i n e 100 - L i g h t R a i l I N E F F : F a ll 200 8
M O NDA Y T HRU F R IDA Y
D IR E C T IO N = E A S T -W E S T
A B C D E F G G F E D C B A
NO. OUT WES T DEKA LB LORAIN DN T WN MIDD LE SOT O EAS T IN NO. OUT EAS T SOT O MIDD LE DN T WN LORAIN DEKA LB WES T IN
BLOCK CARS RU N YA RD T ERM ST A ST A T ERM BUR G ST A T ERM YA RD LVE . BLOCK CARS RU N YA RD T ERM ST A BUR G T ERM ST A ST A T ERM YA RD LVE .
1 1 22 : 0 0 22 : 0 8 22 : 1 4 22 : 2 5 22 : 3 4 22 : 3 9 22 : 4 6 23 : 0 0 1 1 23 : 0 0 23 : 0 7 23 : 1 2 23 : 2 1 23 : 3 2 23 : 3 8 23 : 4 6 0:00
3 1 22 : 1 5 22 : 2 3 22 : 2 9 22 : 4 0 22 : 4 9 22 : 5 4 23 : 0 1 23 : 0 5 3 1 23 : 0 5 23 : 1 2 23 : 1 7
15 1 22 : 3 0 22 : 3 8 22 : 4 4 22 : 5 5 23 : 0 4 23 : 0 9 23 : 1 6 23 : 3 0 15 1 23 : 3 0 23 : 3 7 23 : 4 2 23 : 5 1 0:02 0:08 0:16 0:26
Note that we were primarily concerned with checking the balance of early pull-outs against
final pull-ins. But imbalances can also occur from AM Peak pull-ins at each yard that are not
equal to PM pull-outs from those same yards. Our symmetrical schedule assured equal pull-ins
to pull-outs in the midday, but if the number had not been equal, we could rectify it either by
adding a trip in the midday or at the end of the day. In other words, the between-peaks counts
do not have to be equal, but the difference still has to be made up somewhere in the schedule.
The rule of thumb is: total pull-outs from each yard must equal total pull-ins. The scheduler
who pays attention to this rule wins friends and credibility among the operating ranks.
One more comment on this topic: yard balancing has implications for our eventual runcut.
Even though our yard count balances for this schedule, no less than of the trains pull out
of one yard and pull in to the other. To assure that all blocks returned to their place of origin
would, in this case, require at least more one-way trips, which we have already decided
would be unproductive. We have a number of cheaper ways of taking care of crews returning to
the wrong yard within the runcut. We can deadhead crews cheaper than we can trains. We can
also swap crews from two "off yard" trains at some point before the end of their runs. Finally,
we may have the ability within our work rules to terminate crews at one yard and bring them
back on after a split at the other.
Adding and Cutting Cars
Looking again at our sample schedule, we note that a column has been added for train make-
up, the number of cars that make up the train for each trip. This number can change quite a bit
during the day. Standard practice on light rail systems is to operate two-car trains during base
periods. Some systems add one or two more cars during peaks. Usually evening and night ser-
vice is handled by single cars. Our system follows this practice, although we do not add cars for
the peaks just to keep the example schedule from becoming too complicated.
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Although there are transit systems where consist length is handled as transit board policy,
for the most part it is the scheduler, along with his/her manager/supervisor, who decides the
number of cars that will be required as he/she has the traffic check information available in
order to make a knowledgeable decision on how many cars will be required at max load points
in order to meet the system standards for loadings. One reason for constructing light rail lines
is their large passenger carrying capacity. A standard articulated light rail car which is -
feet in length can seat per car and carry another standees comfortably. Multiply this by a
three-car train, and you have the capability of transporting almost people on a single trip
and with the economy of only one operating crew member--the train operator. It would take at
least six regular buses to provide the same capacity.
However, there is a significant expense in carrying around cars that are not needed to meet
load requirements. So the scheduler should be expected to create an Add and Cut list in con-
junction with the schedule to assure that proper vehicle utilization takes place.
For our schedule, we note that all blocks pull out with two cars. This can be set up by yard
crews and be ready for the train operators. Nothing here needs to be scheduled, other than the
pull-out itself. Since we are not adding or cutting for the peaks, the first time the train consists
change is after the PM peak and the beginning of the evening service. Our short trip blocks can
pull in as two-car trains, as can some of the full trip blocks. Again, the scheduler does not need
to include these as cuts. The blocks which stay out all lose their second cars beginning with the
: departures from both terminals (shown below). The exact movement for getting these
second cars back to the yard is usually worked out by the Light Rail Operations people. They
may cut incoming trains and accumulate cars up to a maximum number which they can ferry to
the yard. All the scheduler needs to do it is to note the cut on the schedule.
3 Rail cars consume significant amounts of electricity simply "rolling along the rails." Further, as preventative maintenance is done on
an accumulated mileage basis, having excess cars in a train will trigger more inspections than are truly warranted. The cost-savings of
reducing excess car miles by repeated adds and cuts is often offset by the necessity to staff yards with "switching" crews (switching
cars onto and off trains). It could well be less expensive to operate excess car miles rather than add additional staff at the yards. This is
a detailed trade-off analysis that often falls to the scheduler to perform.
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HE A D W A Y S HE E T
Line 100 - Light Ra il IN EFF: Fa ll 2008
M ONDAY THRU FRIDAY
DIRECTION = E A ST-W E ST
A B C D E F G G F E D C B A
NO. OUT WEST DEKALB LORAIN DNTWN MIDDLE SOTO EAST IN NO. OUT EAST SOTO MIDDLE DNTWN LORAIN DEKALB WEST IN
BLOCK CARS YARD TERM STA STA TERM BURG STA TERM YARD LVE. BLOCK CARS YARD TERM STA BURG TERM STA STA TERM YARD LVE.
3 2 18:15 18:23 18:29 18:40 18:49 18:54 19:01 19:15 10 2 18:45 18:52 18:57 19:06 19:17 19:23 19:31 19:45
16 2 18:31 18:37 18:48 18:57 19:02 19:07 8 2 19:00 19:05 19:14 19:25 19:31 19:39 19:49
15 2 18:30 18:38 18:44 18:55 19:04 19:09 19:16 19:30 1 1 19:00 19:07 19:12 19:21 19:32 19:38 19:46 20:00
2 2 18:46 18:52 19:03 19:12 19:17 19:22 3 1 19:15 19:22 19:27 19:36 19:47 19:53 20:01 20:15
5 2 18:45 18:53 18:59 19:10 19:19 19:24 19:31 19:45 15 1 19:30 19:37 19:42 19:51 20:02 20:08 20:16 20:30
4 2 19:01 19:07 19:18 19:27 19:32 19:37 5 1 19:45 19:52 19:57 20:06 20:17 20:23 20:31 20:45
7 1 19:00 19:08 19:14 19:25 19:34 19:39 19:46 20:00 7 1 20:00 20:07 20:12 20:21 20:32 20:38 20:46 21:00
9 1 19:15 19:23 19:29 19:40 19:49 19:54 20:01 20:15 9 1 20:15 20:22 20:27 20:36 20:47 20:53 21:01 21:15
17 1 19:30 19:38 19:44 19:55 20:04 20:09 20:16 20:30 17 1 20:30 20:37 20:42 20:51 21:02 21:08 21:16 21:30
10 1 19:45 19:53 19:59 20:10 20:19 20:24 20:31 20:45 10 1 20:45 20:52 20:57 21:06 21:17 21:23 21:31 21:45
1 1 20:00 20:08 20:14 20:25 20:34 20:39 20:46 21:00 1 1 21:00 21:07 21:12 21:21 21:32 21:38 21:46 22:00
3 1 20:15 20:23 20:29 20:40 20:49 20:54 21:01 21:15 3 1 21:15 21:22 21:27 21:36 21:47 21:53 22:01 22:15
The Add and Cut list is arranged as a table at the bottom of the schedule. There are columns for
pulling out and in between the peaks as well as the columns for the initial AM pull-outs and late
PM pull-ins. Most of the table for this schedule just shows blocks as OUT or IN, reflecting that
the yard has set up the train size and nothing changes on the road. In the Last column you see
times when each block is due to have its second car cut. The list is divided between the two cut
points...each end terminal. This time listing is invaluable for the operating personnel who must
assign employees to either cut the second cars or assist the train operators who do the cutting.
AD D S AN D C U T S
AM AM PM PM
TRA IN A DD C UT A DD C UT
AT W ES T TERM IN AL
7 O UT 18:50
9 O UT 19:05
17 O UT 19:17
10 O UT 19:31
AT EAS T TERM IN AL
1 O UT 18:50
3 O UT 19:01
15 O UT 19:16
5 O UT 19:31
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One aspect of adding and cutting that will affect the scheduler is the availability of employees
to do the actual work. The policy of the particular light rail system may be to use yard crews. If
so, many systems schedule these crews as Miscellaneous Runs. Yard work is often included as
pieces within regular train operator runs. The need is to schedule crews so they are on hand for
tasks such as cutting and adding while still having yard crews available for the yard.
Besides the Add and Cut sheet, the scheduler will add a second mileage column to the Block
Summary table to account for the mileage of the second car of each train. If additional cars are
regularly used, a third and even a fourth car mileage column is added. Mileage for these cars
can be calculated in the same manner as for the primary car--but placing a count for each trip
and pull-out/pull-in pattern in the mileage table. We are usually not concerned about the ve-
hicle hours of the extra blocks, as they will not have crews assigned to them and so are not part
of the vehicle hours of the schedule. If Operations or Maintenance rely on operating hours for
costs or for scheduling inspections, then the hours may need to be accumulated for the cars as
well, but these hours should not be mixed into the primary Vehicle or Platform Hour calculation
for the schedule.
Scheduling of Yard Staff
As discussed above, operating personnel are required to staff yards; they hostle equipment
into and out of shop buildings, switch cars onto and off of trains (adding and cutting), bring
equipment to terminal platforms, etc.
Unlike "runs," this work is scheduled more typically like nontransportation jobs, e.g., police
officers. That is: in transportation, the scheduler has prepared two sets of schedules, one for
the equipment and then one for the personnel to operate the equipment. In nontransporta-
tion work, only personnel are scheduled. Because it is not mated to an equipment schedule it
is scheduled to the need for staff presence, not equipment operation. The determination of
staffing levels is based on the needs of the operating departments--Transportation and Main-
tenance. Typically, after Maintenance identifies their needs to Transportation, the Transporta-
tion Department will combine them with their internal needs and ask Schedulers to include
them for posting/picking, i.e., the "Miscellaneous Runs" mentioned above. Sometimes they
will be rostered separately (if the yard jobs are their own job class); sometimes not only are the
rosters comingled with the "road" (revenue) jobs on pick sheets, but some individual jobs are a
combination of road and yard work as previously discussed. But quite often, yard staffing work
is not part of the vehicle blocking/run cutting process. Indeed, at some systems, the Schedules
department isn't even involved in the scheduling and posting of yard work.
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Heavy Rail Scheduling
Since we used a typical light rail scheduling exercise, it would be of interest to contrast it with
a typical heavy rail (subway or elevated) schedule. As mentioned earlier, heavy rail systems
always have the benefit of being completely separated from other traffic (there are a couple of
exceptions, but those really prove the rule).
Here are some differences in heavy rail scheduling:
· Running times would vary only slightly throughout the day. What changes there are
would reflect ( ) increased dwell time at stations because of the increased passenger
activity and ( ) potentially heavy train traffic, especially if headways are below three
minutes.
· Longer trains are generally run. The average heavy rail train is four to six cars. The
schedule usually tracks the consists as they change, but adding and cutting cars is more
the role of the operating personnel and not usually tracked on the schedule.
· Closer headways at most times of the day than found on typical light rail lines. Heavy
rail generally is a mode chosen for its greatly increased passenger carrying capacity,
and this is reflected in the schedule.
· On some systems where lines merge and diverge, extra care must be taken to assure
the spacing of trains along common portions of routes. Sometimes several lines must
be scheduled together because of the interplay between them. Typically, heavy rail
schedules take much more time to build because of these factors, regardless of whether
the scheduler builds them by hand or by computer.
· Heavy rail systems favor doing crew drop-back at terminals. This is because the plat-
form capacity and the short headways dictate a quick turnaround of equipment, which
would not provide adequate layover for crews. It is not unusual for runs on heavy rail to
be multiple-piece runs, with each piece working only one trip on each vehicle.
· Although the trend has been to go to one-person operation over the last years, there
are still heavy rail systems which use conductors. Conductor runs generally follow that
of the train operator, but not always. This can add that much more complication to
constructing the schedule. In some cases, the conductor has different allowances from
the train operator.
· Heavy rail schedules tend to change less frequently than light rail schedules. How-
ever, normal maintenance and construction often requires highly detailed alternate
schedules to account for single tracking, line cutbacks, bypassing stations, and other
methods of freeing track segments for maintenance. These usually occur on weekends.
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Schedulers are challenged to rewrite the service to accommodate the maintenance
while returning the service to normal for the Monday morning rush hour.
Terminal Design and Scheduling Efficiency
As discussed at the beginning of this chapter, one difference between rail and bus scheduling is
the potential for a scheduler to provide vital input to the planners and engineers designing the
layout/trackwork for a new or rebuilt rail terminal. The closest bus counterpart is when a major
transit center with expansive facilities is about to be constructed.
There are lines that simply terminate at a platform in a one (single) track configuration (Dia-
gram ). The side track in Diagram goes to the yard. This arrangement is most commonly
used on lines with wide headways that will remain wide for the foreseeable future.
But for the most part--and the model used for the scheduling examples in this chapter--rail
terminals are center (sometimes called island) platforms with a track on each side and a cross-
over "in-front" of the station (Diagram ).
These have their limitations, notably capacity in terms of headways and passenger conve-
nience. When things go off-schedule, particularly in the PM rush, trains will accumulate wait-
ing to get into the terminal station. On-board passengers are quite anxious; not only are they
already late, but they are invariably standing, crowding near doors, hoping to make a dash exit
to their connecting bus--which itself may be on a -minute or longer headway. They don't
want to suffer through a missed connection.
Diagram is a schematic track layout of a rail terminal that in application can provide for tight
intervals, good delay management as well as minimum train [time] movement/reduced train
and crew count.
Use of cross-over A--which should be as close to the platform as possible in order to minimize
the effective single track length--is the same in Diagrams , , and .
If the terminal is built along the lines of Diagram , use of crossover B is preferred, provided
that the increment of length/running time it adds does not require an additional consist and/
or crew in the cycle. This provides customers the fastest ride from the prior station into the
terminal with little, if any, delay. This is because the train can approach the terminal at normal
station arrival speed on tangent track and does not need to slow down to cross over.
4 For Diagram 2 and for Diagram 3 when crossover A is used, when both tracks at the terminal are empty, the inbound track is the
preferred arrival track so that, if need be, when it departs an arriving train need not be "held out" and can, coincidentally, arrive on the
other track without delay.
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Diagram 1
A Platform
Diagram 2
Inbound
Platform
Outbound
A
Diagram 3
Inbound
Platform
C
Outbound
A B
Diagram particularly works well in schedules where there are drop-back crews. When the
train does arrive, the drop-back crew will board at the rear of the train, "ride" into the "pocket"
and reverse the train's direction with the original crew alighting when the train gets back into
the platform.
Use of loop C, again if it does not require an additional consist and/or crew in the cycle, is op-
erationally superior but more costly in terms of accumulated car miles. Much of this, of course,
will depend on the actual length and radius of the loop.
The reason for this superiority in service delivery is because the train's motion is one that is
continuous; the terminal is nothing more than another station to be stopped at. Critically,
when properly operated, passengers are on board trains that are not held out of the station
(it is important in looping operations that crew reliefs/drop-backs be done on the inbound/de-
parture track). This is particularly important on lines where tight headways are operated for
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sustained periods ( - minutes or longer). In fact, in such cases, there is merit to a design
where there is space on the loop for trains to accumulate, getting off the mainline and "out-of-
the-way" in the peak. In off-peak periods crossover B can be used, and during periods of wide
intervals, even A.
There are, of course, permutations and various combinations, which are dependent on land
availability and associated cost factors. It is highly desirable if Diagram is selected to have tail
tracks with a crossover behind the station in addition to the basic design. This is so both a pull-
back operation (the preferred operating method in Diagram ) can be used in peak periods on
the tail tracks as well as off-peak storage of out of service cars/consists, minimizing car-miles.
Knowledge of the impact of these designs on scheduling is imperative. As a scheduler, you
want to bring to the table recommendations for the least-cost, most-flexible, and most-pas-
senger-friendly design appropriate.
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