Transit Stop Consolidation Evaluation of State of Practice

ADEC GIS-T 2011, St. Petersburg, Fl 1

Transit Stop Consolidation Evaluation of State of Practice

GIS in Transit 2011St. Petersburg, Florida

Sep. 13-15, 2011Maaza Mekuria, PhD, PE, PTOE

ADECorpSan Jose, CA


Modeling Paradigms

• Continuous – Pros

• Useful for exploring relationships between variables (demand, spacing, volume)

– Cons • Lacks sensitivity to

– Location/safety– demand concentration– Access network geometry


Modeling Paradigms

• Discrete – Pros (can be made to be sensitive to)

• Physical location• Demand intensity• Access network geometry

– Cons • Requires

– More detailed data – Robust analytical tools– More time


Stop Spacing Impacts

optimum

0

5

10

15

20

25

30

35

200 240 280 320 360 400 440 480 520 560 600 640

Stop Spacing (m)

Tim

e (m

in)

Access Time

In-Vehicle Time

Total Impact

Oper. Time

Region "A" Region "C" Region "B"


Modeling Stop Spacing

• Single/Bi-Directional Stops

• Multiple Periods

• Sensitivity to Various Input Parameters

• Common Base for comparison

• What if scenarios


State of the Practice

• Rule of Thumb based on– Demand at a stop– Proximity to the nearest stop– Other policy considerations


Stop Spacing Optimization

• Geographic modeling – Walk impact using real street network– Demand density using parcel attributes– Stop enumeration– Multi-period analysis – Sensitivity analysis


Service Area Analysis using three data sets


DP Immediate Cost Computation

• To find costs at j, need to specify at least 1 or more predecessor successor stops

• >=1-dimensional search space


Quintuplet DP Algorithm

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),,,;(),,,;(),,,;({),,;( min)(max)(min

mkjlf

mljikopermljikridemljikwalkljikfkSmkS

walk(k; i,j,l,m) - sum of walking cost impacts associated with stop k over all periodsride(k; i,j,l,m) - sum of riding cost impacts associated with stop k over all periodsOper(k; i,j,l,m) - sum of operating cost impacts associated with stop k over all periodsf(l; j,k,m) – optimal return function cost impacts associated with stop l to the end.


Study Area I Transit Details • Route 57 Crosstown Bus

– Kenmore to Watertown 45 Inbound and 43 Outbound existing stops• Peak ridership

– AM East Bound to Kenmore– PM peak Westbound to Watertown


Study Area II Transit Details • Route 1

Crosstown Bus

35 SB, 36 NB existing stops

• Peak ridership

– Balanced in both directions


Rt 57 Cross-town Bus DP Result Comparison Vs Consultant

Recommendation (Inbound dirn.)

number of stops (Inbound)

Change in Walk Time (Pax-Min/Day)

Change in Running Time (min)

Change in Walk Cost ($/Day)

Change in Ride Cost ($/Day)

Change in Operating Cost ($/Day)

Change in Total Cost ($/Day)

Existing 45

Analyst recommendation 31 7669 -1.9 $3,672 -$2,509 -$488 $674

DP Optimum 32 3955 -1.8 $1,761 -$2,211 -$469 -$920


Rt 1 Cross-town Bus DP Result Comparison Vs Consultant

Recommendation

Total 2-way stops

Average walk time (min)

Average ride time (min)

Avg two-way running time (min)

Change in Walk Cost ($/day)

Change in Ride Cost ($/Day)

Change in Oper Cost ($/Day)

Change in Total Cost ($/Day)

Existing 71 3.46 36.4 88.5 0 0 0 0

Analyst recommendation 55 3.77 35.7 87.4 705 -267 -113 326

DP Optimal 45 3.57 35.5 86.1 243 -218 -156 -132


Summary

State of the Practice can not capture all factors

Use of standard data sets

Appropriate tools with flexibility

Analyst input

Geographic Output


Questions?

Transit Stop Consolidation Evaluation of State of Practice

Documents

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