Transit Signal Priority in Baltimore: Lessons learned - It’s not just about technology
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Transcript of Transit Signal Priority in Baltimore: Lessons learned - It’s not just about technology
Lessons Learned from 10-Years of Operating Transit Signal Priority:
It’s Not Just about the Technology
Howard Street, Baltimore, Maryland
Keith Riniker, P.E., PTOE
Presented by:
Lessons Learned from 10-Years of Operating TSP in Baltimore: It’s NOT Just About Technology
Outline
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1. Overview of Howard Street LRT & TSP 2. TSP Background 3. Successes & Failures 4. Our Latest Project 5. Best Practices
Lessons Learned from 10-Years of Operating TSP in Baltimore: It’s NOT Just About Technology
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Lessons Learned from 10-Years of Operating TSP in Baltimore: It’s NOT Just About Technology
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Lessons Learned from 10-Years of Operating TSP in Baltimore: It’s NOT Just About Technology
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Station Dwell Times – Averages: 30 – 60 sec – Higher with handicap – Standard Deviation: 20 sec
Lessons Learned from 10-Years of Operating TSP in Baltimore: It’s NOT Just About Technology
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Lessons Learned from 10-Years of Operating TSP in Baltimore: It’s NOT Just About Technology
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Transit Signal Priority Overview
Lessons Learned from 10-Years of Operating TSP in Baltimore: It’s NOT Just About Technology
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Transit Signal Priority Equipment Train Equipment Traffic Signal Equipment
Lessons Learned from 10-Years of Operating TSP in Baltimore: It’s NOT Just About Technology
Transit Signal Priority Settings
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• Opticom/GTT GPS – Phase Selectors, Spread Spectrum Radios, On-Board Train Equipment
• Distance-based Zones (not time-based) – 400’ Block Lengths
• 7 to 10 second TSP Alt. Splits
Lessons Learned from 10-Years of Operating TSP in Baltimore: It’s NOT Just About Technology
Sound Bites: Successes
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• “TSP and signal optimization reduced transit signal delay about 40%”
• “TSP …experienced a 10% improvement in travel time”
• “Average of (three minutes) 15% reduction in running time”
• “25% reduction in bus travel times with TSP”
Lessons Learned from 10-Years of Operating TSP in Baltimore: It’s NOT Just About Technology
Failures
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• “Downtown …was originally running on priority but has been shut down …due to inconsistencies in the system.” Minnesota
• “Most of the [TSP] hardware and configuration has gone to the weeds as they do not have the staff to maintain it.” Texas
• “The [MD 210 TSP] installation was discontinued because it didn’t provide desired time travel benefits without resulting in excessive congestion on minor roads.” – Maryland
• “WMATA concluded that TSP had no impact on decreasing bus travel time for the 79 Route [on Georgia Ave], citing two main problems…related to the green extension…and that TSP was limited to one call every 10 minutes.” – Washington, D.C.
• In 2013, the MTA began re-assessing the TSP system on Howard Street and found that TSP was only fully functioning at only 50% of signals. Baltimore
Lessons Learned from 10-Years of Operating TSP in Baltimore: It’s NOT Just About Technology
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Baltimore’s TSP History
Lessons Learned from 10-Years of Operating TSP in Baltimore: It’s NOT Just About Technology
TSP Frequencies (Peak Hours for 1 day, 2 busiest intersections)
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• Lombard St – TSP in both directions – TSP- 20% of cycles (avg.)
– AM
• SB Train stops 60% of Time • NB Train stops 20% of Time
– PM • SB Train stops 50% of Time • NB Train stops 100% of Time
• Pratt St – TSP SB Only (NB, Near-Side) – TSP - 0% of AM cycles, 17%
Midday and 6% of PM – AM
• SB Train stops 0% of Time • NB Train stops at Station
– PM • SB Train stops 100% of Time • NB Train stops at Station
Lessons Learned from 10-Years of Operating TSP in Baltimore: It’s NOT Just About Technology
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• 20% of Cycles are TSP in AM Peak
• Average over 60 minutes, changes split by 2 seconds – No LOS Change (LOS C) – Avg. Intx. Delay + 2 sec.
TSP Frequencies: Lombard St Example • 4 TSP Events in 10 Minutes
of AM Peak, 4/5 Cycles – LOS Changes to E
Lessons Learned from 10-Years of Operating TSP in Baltimore: It’s NOT Just About Technology
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Percentage of TSP Cycles
TSP Cycle = a traffic signal cycle where TSP was granted LRT incident during PM peak observations from Mulberry to MLK/Chase. PM TSP data not reported
Lessons Learned from 10-Years of Operating TSP in Baltimore: It’s NOT Just About Technology
Approach
• Account for Station Dwell Times – Normal boarding / alighting (not incl. HC) – Start-up Lost time
• LRT Vehicle Characteristics – Max / min speed in each block – Acceleration and deceleration
• Trade-Offs in Signal Timing – “Don’t Touch” Signals – Signals to adjust to maximum LRT advantage – Only Minor Adjustments
• Time-Space Diagram Design
Lessons Learned from 10-Years of Operating TSP in Baltimore: It’s NOT Just About Technology
Lessons Learned from 10-Years of Operating TSP in Baltimore: It’s NOT Just About Technology
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CamdenYards
STATION &Conway St
Signal1
Camden StSignal
ConventionCenter
STATION &Pratt StSignal
Lombard StSignal
Baltimore StSTATION &
Signal
Fayette StSignal
Lexington StSignal
LexingtonMarket
STATION &Saratoga St
Signal
Mulberry StSignal
Franklin StSignal
Centre StSignal
CentreStreet
STATION &Monument
St Signal
Madison StSignal
MLK BlvdSignal
CulturalCenter
STATION &Dolphin/Park Ave
Signal
Mt Royal StSignal
Mt RoyalSTATION2
Tim
e:M
in:S
ec
Average Northbound Light Rail Vehicle Delay TimePM Peak Period (4:00 - 6:00)Dec 4th, 16th, & 17th, 2014Average Start-up/ Lost Time
Average Traffic Signal Delay
Average Boarding/Alighting
Delay increase is random; there were no changes in signal timings (Pattern 26)
here.
Broader TSP domain
could reduce delays
PM - After Signal Timing
Lessons Learned from 10-Years of Operating TSP in Baltimore: It’s NOT Just About Technology
Average Travel Time (minutes : seconds)
Time of Day – Train direction
Before After Improvement
PM - SB 15:16 14:54 2% PM - NB 16:57 13:34 20% AM - SB 15:17 14:21 6% AM - NB 14:26 13:47 5% Midday - SB 16:17 14:01 14% Midday - NB 13:46 14:11 -3% Average 15:20 14:08 8%
Before After Improvement
11:41 10:43 8%
11:16 09:00 20%
10:31 09:50 6%
09:17 08:59 3%
12:03 10:08 16%
09:46 09:23 4%
10:46 09:41 10%
Camden Yards to Mt Royal From Camden Yards to Madison
Lessons Learned from 10-Years of Operating TSP in Baltimore: It’s NOT Just About Technology
Sources of Delay (minutes : seconds)
Time - Direction
Total Travel Time
Run Time (> 5 mph)
Station Delay
Signal Delay
PM - SB 14:54 07:14 04:03 03:37 PM - NB 13:34 06:30 05:05 01:59 AM - SB 14:21 06:49 03:00 04:31 AM - NB 13:47 06:40 03:33 03:35 Midday - SB 14:01 07:07 03:36 03:18 Midday - NB 14:11 06:43 03:52 03:36 Average 14:08 06:51 03:51 03:26
Lessons Learned from 10-Years of Operating TSP in Baltimore: It’s NOT Just About Technology
Chance of Arriving at a Traffic Signal on Green
Time of Day – Train direction
Before After
PM - SB 50% 60% PM - NB 65% 70% AM - SB 52% 62% AM - NB 74% 69% Midday - SB 49% 52% Midday - NB 66% 85% Average 59% 66%
Favor SB in the AM at
some expense to
NB
Lessons Learned from 10-Years of Operating TSP in Baltimore: It’s NOT Just About Technology
Challenges
• TSP is located in “no man’s land” • TSP is transparent & MTA does not have easy access • Short Blocks – not enough advance notice for TSP • High-Block Handicap Inefficiencies & Variable Dwell
Times • LRT Drivers Characteristics
– Passive / Start-up Delay – Max Speed, Acceleration Rate – Knowledge of Patterns – Speed of assisting handicap passengers
• LRT Bunching • LRT Signal Head Visibility • Some signals don’t have communications
Lessons Learned from 10-Years of Operating TSP in Baltimore: It’s NOT Just About Technology
Lessons Learned • Lack of Understanding of TSP complexities • Agencies Must Both be Stakeholders • Delays are between signals and stations are equal • Planning for Station Dwell Times Worked…mostly • Need Performance Feedback from ATMS
– Similar to a split monitor • Know Your Controller Parameters • Preventative Maintenance • On Howard St - Passive TSP (signal timing) is more
effective than Active TSP • Some intersections don’t need TSP…some do