The Relationship of Scheduling to Costs

Introduction• Robert Madison – Manager, Scheduling &

Analysis

• Ken Halliday – Senior Scheduler

Scheduling Process• Transit Scheduling Definition (verb) - the

act of designing a relationship between time and space – creating a plan for when a vehicle will pass by a specific geographic location.

• Because of the geographic aspect, efficient scheduling is not a “stand alone” activity, it has to be related to the route design.

Scheduling process (overview)1. Understand the challenges and

opportunities

2. Understand the constraints

3. Collect information

4. Collect basic running time data

5. Refine running times

6. Determine cycle time

Scheduling process (overview)7. Build trip schedule

8. Block trips

9. Runcut blocks

10.Finalization and wrap-up

Scheduling process (approaches)

• Network/route design and scheduling go hand-in-hand

• Various approaches‣ Hub and spoke

»Often with timed transfers

‣ Loops»High coverage vs. inconvenient routings/timings

‣ Grid»Often offers best headway opportunities

Hub and Spoke network• Schedules are designed so several buses arrive

at one location at specific times to facilitate transfers.

• Also known astimed-transfer, orpulse network

Hub and Spoke network (pros)• Maximize transfer

opportunities‣ Often with timed

transfers/scheduled meets

• Most passengers can get to main hub on one-seat ride

Hub and Spoke network (cons)• Very little flexibility with

route length‣ Bus has to be able to get

back to hub to meet with other buses

• Delays cause significant disruption‣ One late bus can make

every bus late

• Not convenient for travel between outer ends of adjacent spokes

Loop networks (pros)• Maximize coverage

area with fewer vehicles

• Really, seriously, not much else.

Loop networks (cons)• Indirect routings• One-way loops offer no

easy return trip options• Hard for passengers to

understand• Not always a clear start

and end point‣ Interlining can be difficult

if the bus is expected to continue on its loop routing

Loop networks

Grid• Buses are scheduled to run frequently so

wait times for transfers are minimized.

Grid networks (pros)• Allows for best headway /

frequent transit

• Convenient for transferring anywhere in system

• Straightforward, logical

• Allows for less service duplication

Grid networks (cons)• Not easy to do timed

transfers‣ Each route can have

different headways‣ Too many transfer

possibilities to try and make individual ones work

• Local street network must work for grids

Short turns & branches• Useful where demand on one portion of a

route is significantly higher than demand on another portion

• Multiple outlying areas need service to a single dense corridor

Short turns & branches• Short turns should actually save money in

order to be logical

• Branches necessarily must have a headway that is a multiple of the trunk headway.

Route Design/Structure• Efficient, lower cost systems ideally run

buses through dense population areas

• Take passengers to/from popular destinations ‣ Employment centres‣ Shopping and entertainment centres‣ Schools

Service Standards and Policies• Define your transit system’s “reason for

being”.

Service Standards and Policies• Policies and standards used in service

development

• Balance between cost efficiency and provision of adequate service to the public

Cycle time• The amount of time it takes for a bus

operate a round-trip (i.e. both directions, or one loop), including layover/recovery.

B

A

Cycle time• Good route design takes into account

cycle time• For “clock-face” headways (frequencies),

design routes that have a cycle time that can be divided by your headway (15/30/60 minutes)

Cycle time• Cycle time drives the number of buses

required to operate service

Cycle time / interlining• How do you maintain efficiency if you can’t

design routes with even cycle times?‣ That’s where you employ interlining

• Example‣ Route 100: 37 minute cycle‣ Route 200: 40 minute cycle‣ Route 300: 38 minute cycle‣ 30 minute frequency

Interlining• Example:

Interlining• Same trips, interlined

Interlining• Without interlining

‣ 6 buses‣ Long layovers

• With interlining‣ 115-minute total cycle‣ 4 buses‣ Less excess recovery time

Interlining

No interlining With interlining

In-service time 42h55 42h55

Pull in/out trips 9h00 6h00

Layover 29h31 6h45

Buses used 6 4

Total time 81h26 55h40

Interlining (pros vs. cons)• Pros

‣ More efficient use of vehicle/driver time‣ Reduce excess recovery‣ Can offer additional direct service

• Cons‣ Delays on one route may impact others‣ Only works if vehicle types compatible on all

trips/routes

Small schedule tweaks

5 Min

Small schedule tweaks

Peak vs. Off-peak service• Typical weekday “vehicles in service” graph

Peak vs. Off-peak service• Typically, “base” service (midday service)

cheapest to add

• Peak service typically most expensive‣ Assuming service span is fixed. Adding new service

day or extending service day can have lots of overhead costs.

• “Shoulder” peak usually more expensive than base‣ Just before AM peak‣ Just after PM peak

Runcutting• Often overlooked in overall system design

• Can be a key driver of efficiency, particularly for larger systems

• Impacted by collective agreement work rules‣ Or even generic work rules if no CA

Overtime vs. adding drivers?• Consider cost of having extra drivers vs.

cost from overtime

• Often, fixed costs for employees (benefits, vacation, training, etc.) exceed overtime

• Must balance with driver quality of life, fatigue from longer hours, etc.

OT vs. adding drivers example• Total of 240 hours per weekday• Driver pay = $25 / hour• Overtime (1.5x pay) after 8 hours• 250 weekdays per year• Each run costs $30,000/year in fixed costs

‣ Vacation benefits for driver‣ Health benefits for driver‣ Training and other administrative costs‣ Extra board

OT vs. adding drivers example# of daily shifts 30 29 28

Average shift length 8 hours 8.28 hours 8.57 hours

Straight time pay per run/day $200 $206.90 $214.29

Overtime premium $0 $3.45 $7.14

Total daily pay per run $200.00 $210.35 $221.43

Annual pay total $1,500,000 $1,525,000 $1,550,000

Fixed run cost (total) $900,000 $870,000 $840,000

Total annual cost $2,400,000 $2,395,000 $2,390,000

• Paying ½ hour overtime to fewer drivers saves $10,000/year

Drawbacks of high overtime• Increased driver stress may lead to more sick

time

• Longer hours, particularly at night, can increase fatigue (i.e. higher accident risk)

• Not all drivers want to work longer hours

• Some contracts may specify limits on work time

Spread premium and limitations• Spread: The time from the earliest report to the latest

sign-off for a driver’s work day‣ Piece 1:

» Report 6:00» Pull out 6:15» Pull in 9:30» Sign off: 9:40

‣ Piece 2:» Report 14:00» Pull out 14:15» Pull in 17:45» Sign off: 17:55

‣ Spread: 6:00 – 17:55, 11h55

Spread premium and limitations• Most transit collective agreements have

spread premium‣ E.g. 10% bonus pay for spread beyond 10

hours

• Most also have a maximum spread time‣ Generally 12 or 13 hours, depending on run

type

Spread premium and limitations• Spread limitations can cause difficulty for

runcutting in certain cases‣ Service operates far from downtown (has to start

early/finish late)‣ Service levels drop off later in PM rush/early

evening‣ Limited opportunities to mix with other services

• Because of spread premium, can make adding service more expensive at certain times of day

Spread premium and limitations• Filling in midday is often cheaper than adding to

the outer edge of the peaks

More $ More $Cheaper

Vehicle blocking and runcutting• Vehicle blocking can drive runcutting costs

‣ Short blocks may have to pay guarantee‣ Blocking can affect efficiency in scheduling

straights and splits

• Most efficient vehicle schedule isn’t necessarily most efficient crew schedule

Vehicle blocking and runcutting• Scenario:

‣ Route operates 5:00-21:00‣ 45-minute cycle‣ 15-minute headway (3 buses) 7:00-9:15,

15:15-18:00‣ 45-minute headway (1 bus) all other times

Vehicle blocking and runcutting• Blocking option 1:

• Total 26h15 vehicle time per day

Vehicle blocking and runcutting• Blocking option 2:

• Total 27h15 vehicle time per day

Vehicle blocking and runcutting• Blocking option 1:

Vehicle blocking and runcutting• Blocking option 2:

Vehicle blocking and runcutting

Option 1 Option 2

Vehicle time 26h15 27h15

Straight runs 1 2

Split runs 1 2

Trippers 3 0

Paid time 34h53 30h15

Pitfalls to avoid• “We can’t afford to schedule accurate

running times”‣ You are paying for it one way or the other‣ Schedule accurate run times to better control

overtime costs/service reliability‣ Increase headway if cost increase can’t be

accommodated in budget

Pitfalls to avoid• Time-consuming diversions to serve few

passengers‣ Mass transit should serve the masses‣ Increase in running time will increase costs

without a commensurate benefit to ridership‣ Passengers on board inconvenienced by

longer trip

Pitfalls to avoid• Trying to guarantee everyone an 8 am

arrival‣ If every route has to have a bus at the same

time, you need a separate bus for every route» Particularly expensive for smaller systems

‣ Reduces ability to gain efficiency through interlining

‣ If possible, try to work with schools, major employers to stagger start/end times

Pitfalls to avoid• Building a bus garage in the middle of

nowhere because the land is cheap

15 K

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Tools to help improve schedules• Automated data collection technology to

help calibrate service levels, cycle times‣ AVL, APC systems generate large amounts of

data for planners and schedulers to use‣ BC Transit currently working on a program to

improve our APC technology‣ Smart Bus program to consider AVL options

Tools to help improve schedules• HASTUS-ATP

‣ Run-time analysis tool offered by GIRO»On wish list for near-term purchase

‣ Uses data from AVL/APC software‣ Calibrates run times and cycle times based on

user-specified criteria for on-time performance

Tools to help improve schedules• MinBus

‣ Vehicle blocking optimizer‣ Finds efficiency in vehicle blocking, reducing

peak vehicle requirements based on parameters set by scheduler

‣ Best for larger systems (multiple garages, multiple vehicle types)

Tools to help improve schedules• CrewOpt

‣ Crew schedule optimizer‣ Finds efficiency in crew scheduling, reducing

overall schedule cost based on parameters set by scheduler

‣ Uses rules based on collective agreement, plus other preferences

The End• Thanks for listening!