11th TRB National Transportation Planning Applications Conference CORRADINO May 9, 2007 1 Validation...

11th TRB National Transportation 11th TRB National Transportation Planning Applications ConferencePlanning Applications Conference

CORRADINOCORRADINOMay 9, 2007May 9, 2007 11

Validation of Speeds and Validation of Speeds and Volumes in a Large Volumes in a Large

Regional ModelRegional Model

Southeast Regional Planning Model – 6Southeast Regional Planning Model – 6

Florida Department of TransportationFlorida Department of Transportation

District IVDistrict IV


CORRADINOCORRADINOMay 9, 2007May 9, 2007

Consultant TeamConsultant Team

SERPM 6SERPM 6CorradinoCorradino

AECOM ConsultAECOM Consult

With thanks to …•FDOT Districts 4, 6 & Turnpike

•MPO staffs of Palm Beach, Broward 7 & Miami-Dade Counties

•SFRTA



SERPM 6SERPM 6

Palm Beach, Broward and Miami-Palm Beach, Broward and Miami-Dade CountiesDade Counties

4,134 TAZs (ZONESA)4,134 TAZs (ZONESA)

3 Time periods (AM 6:30-9:30, PM 3 Time periods (AM 6:30-9:30, PM 3:30 – 6:30, Off-peak)3:30 – 6:30, Off-peak)

10 Transit modes10 Transit modes

22 – 28 hours run time on 3.4 GHZ 22 – 28 hours run time on 3.4 GHZ computercomputer



SERPM 6 - Transit NetsSERPM 6 - Transit Nets# PT Mode (applicable county) TRNBUILD Mode (applicable county)

1 Walk Access Walk Access

2 Drive Access Drive Access

3 Sidewalk/Transfer connector Sidewalk/Transfer connector

4 Bus (Palm Beach & Broward) Bus (Palm Beach)

5 Bus (Miami-Dade) Bus (Dade)

6 Express Bus (all) Express Bus (Broward)

7 Metro-Rail Metro-Rail

8 Tri-Rail Tri-Rail

9 Metromover Metromover

10 New Mode (all) New Mode (Broward)

11 Project Mode (all) Project Mode (all)

12 Tri-Rail Shuttle (all) Tri-Rail Shuttle (all)

13 Limited Stop Bus (all) Limited Stop Bus (Miami-Dade)

14 n/a Bus (Broward)

15 n/a Express Bus (Miami-Dade)

16 n/a Express Bus (Palm Beach)

17 n/a New Mode (Miami-Dade)

18 n/a Limited Stop Bus (Broward)

19 n/a Limited Stop Bus (Palm Beach)

20 n/a New Mode (Palm Beach)



SERPM 6 – Model FlowSERPM 6 – Model Flow

1.1. Setup controls and file namesSetup controls and file names2.2. External – EE by periodExternal – EE by period3.3. Trip Gen – LSGEN by auto Trip Gen – LSGEN by auto

ownership and TODownership and TOD4.4. Highway – Including speed Highway – Including speed

and capacity calculatorsand capacity calculators5.5. Distribution – Including Distribution – Including

equilibration of peak period equilibration of peak period highway speedshighway speeds

6.6. Transit Nets – PT Transit Nets – PT Trnbuild Trnbuild and connectors, paths, skims and connectors, paths, skims and faresand fares

7.7. Mode ChoiceMode Choice8.8. Transit Assignment by access Transit Assignment by access

path and TODpath and TOD9.9. Highway Trip Tables – Highway Trip Tables –

Combines trip tables for Combines trip tables for assignmentassignment

10.10. Highway Assignment – by Highway Assignment – by TOD (use most computer TOD (use most computer time)time)

11.11. Highway Evaluation – HEVAL Highway Evaluation – HEVAL and RMSE by TOD and and RMSE by TOD and countycounty



THE ISSUETHE ISSUE

FTA/FHWA emphasis on correct speeds FTA/FHWA emphasis on correct speeds and travel times in models, especially for and travel times in models, especially for New StartsNew Starts

So, we must:So, we must: Match traffic counts and transit ridership in the Match traffic counts and transit ridership in the

base year.base year. Match observed highway travel timesMatch observed highway travel times Match observed transit travel timesMatch observed transit travel times



Old PracticeOld PracticeAssign uncongested speeds and capacities to Assign uncongested speeds and capacities to links from a lookup table indexed by area type links from a lookup table indexed by area type (AT), facility type (FT) and number of lanes.(AT), facility type (FT) and number of lanes.Default lookup table developed by examining Default lookup table developed by examining practice throughout the state.practice throughout the state.Adjust the lookup table to obtain a better match Adjust the lookup table to obtain a better match of final assigned 24-hour volumes.of final assigned 24-hour volumes.Most adjustments made to speeds.Most adjustments made to speeds.Care taken to ensure “logical” relationships, e.g., Care taken to ensure “logical” relationships, e.g., freeways faster than arterials, rural faster than freeways faster than arterials, rural faster than residential.residential.Transit speeds derived from highway using Transit speeds derived from highway using “INET” functions based on mode, AT and FT.“INET” functions based on mode, AT and FT.



Well, What’s Wrong Well, What’s Wrong With That?With That?

Lookup table probably better than Lookup table probably better than adjusting individual links to get better adjusting individual links to get better loads (not dead yet – what speed does a loads (not dead yet – what speed does a new link get?).new link get?).While lookup tables are systematic, their While lookup tables are systematic, their contents can become arbitrary and contents can become arbitrary and skewed.skewed.Seldom checked to verify they have any Seldom checked to verify they have any relationship to reality.relationship to reality.



New ApproachNew Approach

Base Capacities on Florida Base Capacities on Florida Quality/Level of Quality/Level of Service ManualService Manual, derived from HCM., derived from HCM.Capacities and speeds determined from Capacities and speeds determined from roadway characteristics, not a subjective roadway characteristics, not a subjective determination of AT, FT.determination of AT, FT.Speeds begin with POSTED SPEED, modified Speeds begin with POSTED SPEED, modified by studies of driver behavior.by studies of driver behavior.If signal controlled, add estimated delays at If signal controlled, add estimated delays at intersections, but not microsimulation (somewhat intersections, but not microsimulation (somewhat of a slippery slope).of a slippery slope).Some concessions were made to better match Some concessions were made to better match counts.counts.



Initial Speed EstimationInitial Speed Estimation

Estimates uninterrupted flow initial speed Estimates uninterrupted flow initial speed from an equation.from an equation. Begin with NCHRP 387Begin with NCHRP 387 Modify to make more consistent (remove Modify to make more consistent (remove

discontinuity at 50 mph).discontinuity at 50 mph).

Adds delays from traffic control devicesAdds delays from traffic control devicesLater, speeds are changed in the user Later, speeds are changed in the user equilibrium assignment and equilibration of equilibrium assignment and equilibration of travel times.travel times.



Speed RelationshipsSpeed RelationshipsPosted vs. Initial Speed

0

10

20

30

40

50

60

70

80

90

Posted Speed

Init

ial

Sp

eed

NCHRP

2nd Order

FWY

Surface

FWY=12.56+0.641*Postspd+0.00340*Postspd^2

Surface=9.10+0.657*Postspd+0.00348*Postspd^2



CAPACITIESCAPACITIES

New with SERPM-6.New with SERPM-6.

Replaces the lookup tables.Replaces the lookup tables.

Allows an OVERIDE coded on the link.Allows an OVERIDE coded on the link.

Based on the FDOT Based on the FDOT Quality/Level of Quality/Level of Service Manual.Service Manual.

Script calculates LOS “C” and “E”.Script calculates LOS “C” and “E”.

Calculated as PCE’s.Calculated as PCE’s.



Capacity Calculation Variables/AttributesCapacity Calculation Variables/Attributes



Time of DayTime of DayFSUTMS uses auto speeds FSUTMS uses auto speeds from 24-hour assignment as from 24-hour assignment as for HBW mode choicefor HBW mode choice

HBO & NHB use free-flow HBO & NHB use free-flow speedsspeeds

SERPM6 uses time of daySERPM6 uses time of day Peak period trips use AM Peak period trips use AM

congested speedscongested speeds Off-peak period trips use free-Off-peak period trips use free-

flow speedsflow speeds

Standard FSUTMS design Standard FSUTMS design expected for most modelsexpected for most models

Standard FSUTMS ModelsStandard FSUTMS Models

Purpose & Purpose & PeriodPeriod

Auto Auto ImpedancesImpedances

HBW allHBW all CongestedCongested

HBO allHBO all Free-flowFree-flow

NHB allNHB all Free-flowFree-flow

Time-of-day ModelsTime-of-day Models

Purpose & Purpose & PeriodPeriod

Auto Auto ImpedancesImpedances

HBW peak HBW peak

HBO peak HBO peak

NHB peakNHB peak

AM congestedAM congested

HBW off-peakHBW off-peak

HBO off-peakHBO off-peak

NHB off-peakNHB off-peak

Free-flowFree-flow



EquilibrationEquilibration

Peak speeds and time modified from user Peak speeds and time modified from user equilibrium assignment.equilibrium assignment.Run twice to conserve model running time.Run twice to conserve model running time.Speeds found to be stable.Speeds found to be stable.Produces distribution and mode choice Produces distribution and mode choice travel times for highway and transit that travel times for highway and transit that are close to the times after the final are close to the times after the final assignment.assignment.Times are stable for UB calculations.Times are stable for UB calculations.



SERPM 6 – Mode ChoiceSERPM 6 – Mode Choice

Applied for Peak and Off-peak



SERPM 6 – Highway AssignmentSERPM 6 – Highway Assignment

By Time-of-DayBy Time-of-Day AM PeakAM Peak Off-PeakOff-Peak PM PeakPM Peak Composite 24 Hours (add preceding)Composite 24 Hours (add preceding)



Volume-Delay CurvesVolume-Delay Curves

Southeast Regional Planning Model VISoutheast Regional Planning Model VI



SERPM 6 – Highway EvaluationSERPM 6 – Highway Evaluation

SUMMARIES BY:SUMMARIES BY: SERPM 6 Region by Time-of-DaySERPM 6 Region by Time-of-Day Each County for 24 hoursEach County for 24 hours Trucks alone – each County for 24 hoursTrucks alone – each County for 24 hours



SERPM 6 - ValidationSERPM 6 - Validation

Standard FSUTMSStandard FSUTMSPlus Speed ValidationPlus Speed ValidationSpeed compromises made in favor of Speed compromises made in favor of Volume/CountVolume/CountGood Volume/Count ratiosGood Volume/Count ratiosVery good RMSEVery good RMSEGood transit assignment resultsGood transit assignment results



Highway Highway Sections of Sections of Observed Observed

Speed StudySpeed Study

(from several sources)(from several sources)



2000 Highway Speeds2000 Highway Speeds



SERPM 6 – Speed ValidationSERPM 6 – Speed Validation

Average Weighted Speed (mph)

Model Observed

Facility Type AM PMOff

PeakAll

PeriodsAM PM

Off Peak

All Periods

Freeway - 11 45.41 45.47 48.81 46.44 46.84 54.15 52.25 50.58

Surface Streets - 41 29.86 27.45 31.67 30.13 24.69 23.60 26.62 25.25

HOV Lanes - 81 54.02 51.57 52.79 64.19 57.58 60.89

Toll Facility - 91 63.79 62.17 62.84 62.96 65.16 65.47 63.97 65.17

All Facilities: 41.00 43.94 37.87 40.88 39.97 46.75 35.41 40.48



AM PeriodAM PeriodSpeedSpeed

ValidationValidation



PM PeriodPM PeriodSpeedSpeed




Off-PeakOff-PeakSpeedSpeed




SERPM 6 – Systemwide SERPM 6 – Systemwide ComparisonComparison



SERPM 6 – RMSE ValidationSERPM 6 – RMSE Validation



Highway Screenline AccuracyHighway Screenline Accuracy



ScreenlineScreenlineLocationsLocations



Volume/Count Ratios of ScreenlinesVolume/Count Ratios of Screenlines SL, CL & Corridor Number

Screenline(SL), Cutline(CL) & Corrodor NameNumber of Links

No. of Links with

Counts

Pct of Links with

Counts

Total Count Total VolumeVolume /

Count Ratio

SERPM6 Model

Percent Deviation

Maximum Desirable Percent

Deviation (*)

2 PB: EW Southern SL North of Clintmore Rd 15 15 100% 388,142 416,909 1.07 7

3 PB: EW SL along North of Boynton Beach Blvd 13 13 100% 368,358 379,074 1.03 3

4 PB: EW Middle SL along South of Forest Hill 23 20 87% 509,238 487,878 0.96 4

5 PB: EW Northern SL along N of 45th Street 13 12 92% 339,872 315,405 0.93 7

6 PB: EW Northern SL along N of Donald Ross 13 12 92% 216,862 205,924 0.95 5 1721 BO: EW Northern SL along Pompano Canal 22 20 91% 690,250 676,377 0.98 2 22 BO: EW Middle SL along Oakland Park Blvd 26 24 92% 899,580 849,309 0.94 6 23 BO: EW Southern SL along River Canal 25 23 92% 694,400 832,605 1.20 20 24 BO: NS Western SL between I-75 and Turnpike 23 19 83% 482,300 463,751 0.96 4 25 BO: NS Middle SL along Turnpike 29 28 97% 1,022,000 1,076,407 1.05 5 42 MD: NS SL east of TPK 39 18 46% 613,726 550,309 0.90 10 43 MD: EW SL south of I-75/Gratigney (SR 924) 39 21 54% 660,487 611,412 0.93 7 44 MD: NS SL east of Palmeto Expwy (SR 826) 36 17 47% 788,158 765,205 0.97 3 45 MD: EW Sl south of SR 934 29 20 69% 788,714 808,428 1.02 2 46 MD: NS SL west of SR 9/27th Avenue 45 19 42% 777,148 766,008 0.99 1 47 MD: EW SL south of Dolphin Expwy (SR 836) 36 13 36% 706,229 678,242 0.96 4 48 MD: EW CL along TPK ext and SR 826 24 7 29% 293,960 249,108 0.85 15 1449 MD: EW SL south of SR 986 (72nd St) and Snapper Expwy 25 9 36% 275,501 308,102 1.12 12 1550 MD: NS SL west of I-95 51 23 45% 703,320 722,837 1.03 3 51 MD: EW SL north of 152nd St (SR 992) 13 3 23% 199,448 225,037 1.13 13 1853 MD: EW SL between 200th and 216th St 15 3 20% 43,360 44,892 1.04 4 3618 PB: NS SL along Intra-Coastal Crossings 20 20 100% 319,574 309,389 0.97 3 26 BO: NS Eastern SL along Intra-Coastal Crossings 12 12 100% 285,900 297,601 1.04 4 1452 MD: NS Eastern SL along Intra-Coastal Crossings 15 6 40% 220,646 233,659 1.06 6 17

27 EW SL Palm Beach/Broward County Line 17 13 76% 414,100 455,446 1.10 10 28 EW SL Broward/Miami-Dade County Line 25 23 92% 735,842 812,543 1.10 10

Screenlines (SL)

Inter-County Screenlines



ConclusionsConclusions

Assigning speeds to network links based on Assigning speeds to network links based on posted speeds and traffic control produces good posted speeds and traffic control produces good results in terms of speeds and travel times.results in terms of speeds and travel times.The Florida The Florida Quality/Level of Service ManualQuality/Level of Service Manual is is useful for estimating model capacities.useful for estimating model capacities.Speed and capacity calculators appear to work Speed and capacity calculators appear to work at least as well as lookup tables and are less at least as well as lookup tables and are less arbitrary.arbitrary.It is possible to validate speeds and volumes in It is possible to validate speeds and volumes in a time-of-day model.a time-of-day model.



Recommendations for Future StudyRecommendations for Future Study

Need consistent travel time data.Need consistent travel time data.

Need more travel time data.Need more travel time data.

Consider estimating delays at Consider estimating delays at intersections dynamically using software intersections dynamically using software intersection or junction modeling.intersection or junction modeling.

Better way of estimating the impacts of Better way of estimating the impacts of freeway merge/diverge/weaves on model freeway merge/diverge/weaves on model travel times.travel times.



Questions ? Questions ?

Please use the Microphone.Please use the Microphone.

11th TRB National Transportation Planning Applications Conference CORRADINO May 9, 2007 1 Validation...

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