Microsimulation for Rural and Exurban Regions: Lake County, California

Microsimulation for Rural and Exurban

Regions:Lake County, California

David Gerstle (presenting) & Zheng Wei

Caliper Corporation

Executive Summary

• Microsimulation is an important tool for modeling exurban and rural areas

• Congestion is often not an important driver of travel times

• “Minutia” such as grade, curvature, and lane widths are vitally important

• Shown using a case-study of Lake County, California using Caliper’s TransModeler microsimulation software:– Show how we calibrated & validated the model– Show failure to validate absent grade,

curvature, lane widths, etc.

Outline

• Project Background• Model Scope• Model Preparation• Model Minutia

Outline


Project Background

• Lake County Area Microsimulation Model (LAMM)

• To develop a traffic simulation model that:– Supports planning and operational

analysis– Focuses on SR-20, SR-53, and SR-29 and

the communities surrounding Clear Lake– Extends and complements existing

models and modeling activities• To evaluate future-year scenarios

Project Background






Lake County

Lake County

• Approx. 2 hr. drive from SFO to southern Lake County

LakeCountyLake County

Project Background






• Dominant route for through traffic passes through populated areas

Outline


Outline

• Project Background• Model Scope

– Geography– Time Periods & Vehicle Population

• Model Preparation• Model Minutia

LakeCounty

Study Area

LakeCounty

• 450 square miles of Lake County, from Middletown (Napa border) to Upper Lake (Mendocino border)

Study Area

LakeCounty

Level of Detail

LakeCounty

• 720 miles of roadway (120 miles on State Routes)

• 4,200 Links and 3,300 Nodes• All roads in the regional travel

demand model are included

Level of Detail

LakeCounty

• High level of detail for local streets

Nice

Level of Detail

LakeCounty

• Intersection geometry accurately reproduced

Level of Detail

Outline

• Project Background• Model Scope

– Geography– Time Periods & Vehicle Population

• Model Preparation• Model Minutia

Time Periods & Vehicle Population• Times of day include two peak periods

– 6:00 – 9:00 AM – 3:00 – 6:00 PM

• Vehicle Population– Auto– Truck

Time Periods & Vehicle Population• Times of day include two peak periods

– 6:00 – 9:00 AM – 3:00 – 6:00 PM

• Vehicle Population– Auto– Truck

Outline

• Project Background• Model Scope• Model Preparation

– Data Collection– Model Calibration– Model Validation

• Model Minutia

Outline


– Data Collection– Model Calibration– Model Validation

• Model Minutia

Data Collection

• GPS-recorded travel times• O-D surveys• Turning movement counts• Directional counts

Data Collection

O-D Survey Sites (5)

Turning Movement (20)

Directional Counts (26)

GPS Travel Times

Data Collection



GPS Travel Times


Data Collection



GPS Travel Times



Data Collection



GPS Travel Times

Outline


– Data Collection– Model Calibration – Model Validation

• Model Minutia

Model Calibration

• Take the calibrated travel demand model as the starting point

• Iteratively cycle between– Trying to match turn & directional counts– Trying to equilibrate route choices

• Target traffic count calibration standards set by Caltrans

Model Calibration




Calibrated Travel Demand Model

Match Counts(ODME)

Match Times(DTA)

Calibrated Micro-simulation Model

Model Calibration




1st Hour 2nd Hour 3rd Hour AllIndividual Roads Yes Yes Yes Yes

Total Yes Yes Yes YesIndividual Roads Yes Yes Yes Yes

Total Yes Yes Yes YesIndividual Movements Yes Yes Yes Yes

Total Yes Yes Yes YesIndividual Movements n/a n/a n/a n/a

Total n/a n/a n/a n/a

Individual Roads Yes Yes Yes YesTotal Yes Yes Yes Yes

Individual Roads Yes Yes Yes YesTotal Yes Yes Yes Yes

Individual Movements Yes Yes Yes YesTotal Yes Yes Yes Yes

Individual Movements n/a n/a n/a n/aTotal n/a n/a n/a n/a

PM P

eak

Segment Flows

% Difference

Statistical Significance

Turning Movement

Flows

% Difference


Meets Standard?

AM P

eak

Segment Flows

% Difference


Turning Movement

Flows

% Difference


Outline


– Data Collection– Model Calibration – Model Validation

• Model Minutia

Model Validation

• Take the calibrated traffic simulation model as the starting point

• Iteratively cycle between– Trying to match point-to-point travel times– Reviewing/revisiting model development and

calibration steps• Target travel time calibration standards

set by Caltrans

Model Validation

• Take the calibrated traffic simulation model as the starting point

• Iteratively cycle between– Trying to match point-to-point travel times– Reviewing/revisiting model development and

calibration steps• Target travel time calibration standards

set by Caltrans

Calibrated Traffic Simulation Model

Revisit Calibration(ODME/DTA)

Match Times (Simulation)

ValidatedMicro-simulation

Model

Model Validation

BoundaryUpper Lake

Lucerne

SR-53

Lower Lake

Kelseyville

Middletown

Point-to-Point Travel Times

BoundaryUpper Lake

Lucerne

SR-53

Lower Lake

Kelseyville

Middletown

GPS: 15.95 minTSM: 15.89 min: 0.36%

GPS: 11.29 minTSM: 8.95 min: 23.07%GPS: 16.92

minTSM: 17.79 min: 5.01%

GPS: 13.35 minTSM: 15.03 min: 11.82%

GPS: 6.63 minTSM: 6.82 min: 2.9%

GPS: 15.92 minTSM: 16.17 min: 1.61%

GPS: 20.25 minTSM: 21.63 min: 6.85%

Model ValidationAM Southbound Travel Times

BoundaryUpper Lake

Lucerne

SR-53

Lower Lake

Kelseyville

Middletown

GPS: 15.65 minTSM: 16.53 min: 5.49%

GPS: 13.12 minTSM: 8.93 min: 37.98%GPS: 17.52min

TSM: 18.21 min: 3.84%

GPS: 13.87 minTSM: 14.87 min: 6.99%

GPS: 6.48 minTSM: 6.97 min: 7.21%

GPS: 15.22 minTSM: 16.56 min: 10.56%

GPS: 20.53 minTSM: 21.86 min: 6.31%

Model ValidationAM Northbound Travel Times

BoundaryUpper Lake

Lucerne

SR-53

Lower Lake

Kelseyville

Middletown

GPS: 15.58 minTSM: 16.38 min: 5.01%


minTSM: 17.95 min: 6.26%

GPS: 13.51 minTSM: 15.34 min: 12.73%

GPS: 6.24 minTSM: 6.96 min: 10.92%

GPS: 16.03 minTSM: 16.61 min: 3.56%

GPS: 20.52 minTSM: 21.62 min:5.21%

Model ValidationPM Southbound Travel Times

BoundaryUpper Lake

Lucerne

SR-53

Lower Lake

Kelseyville

Middletown

GPS: 15.02 minTSM: 16.58 min: 9.88%


minTSM: 18.55 min: 9.81%

GPS: 13.12 minTSM: 15.03 min: 13.53%

GPS: 6.55 minTSM: 6.99 min: 6.45%

GPS: 17.31 minTSM: 16.54 min: 4.57%

GPS: 19.96 minTSM: 22.42 min: 11.60%

Model ValidationPM Northbound Travel Times

Model Validation

From To LB TSM TT Avg. TSM TT UB TSM TT Avg. GPS TT % difference TSM is…Boundary Upper Lake 6.68 6.82 6.97 6.63 2.90% LongerUpper Lake Lucerne 15.32 15.89 16.55 15.95 0.36% ShorterLucerne SR 53 14.73 15.03 15.38 13.35 11.82% LongerSR 53 Lower Lake 8.84 8.95 9.06 11.29 23.07% ShorterLower Lake Middletown 21.54 21.69 21.82 20.25 6.85% LongerUpper Lake Kelseyville 15.93 16.22 16.52 15.37 5.34% LongerKelseyville Lower Lake 17.34 17.84 18.43 16.41 8.38% LongerUpper Lake Boundary 6.91 6.97 7.02 6.48 7.21% LongerLucerne Upper Lake 16.30 16.53 16.76 15.65 5.49% LongerSR 53 Lucerne 14.60 14.87 15.17 13.87 6.99% LongerLower Lake SR 53 8.81 8.93 9.05 13.12 37.98% ShorterMiddletown Lower Lake 21.61 21.86 22.13 20.53 6.31% LongerKelseyville Upper Lake 16.35 16.56 16.81 15.22 8.48% LongerLower Lake Kelseyville 17.99 18.21 18.43 17.52 3.84% Longer

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Model Validation


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Lower and Upper Bounds calculated by bootstrapping sample

Model Validation


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1.Create bootstrapped sample of the set of simulation runs2.For each run in bootstrapped sample, create

bootstrapped sample of point-to-point travel times3.Calculate expected travel time for each simulation run

Model Validation


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1.Create bootstrapped sample of the set of simulation runs2.For each run in bootstrapped sample, create

bootstrapped sample of point-to-point travel times3.Calculate expected travel time for each simulation run

Which is to say this is NOT an average of all of the point-to-point travel times

Model Validation

From To LB TSM TT Avg. TSM TT UB TSM TT Avg. GPS TT % difference TSM is…Boundary Upper Lake 6.90 6.96 7.02 6.24 10.92% LongerUpper Lake Lucerne 16.15 16.38 16.61 15.58 5.01% LongerLucerne SR 53 15.13 15.34 15.56 13.51 12.73% LongerSR 53 Lower Lake 9.19 9.30 9.41 10.66 13.64% ShorterLower Lake Middletown 21.42 21.62 21.82 20.52 5.21% LongerUpper Lake Kelseyville 16.34 16.61 16.89 16.03 3.56% LongerKelseyville Lower Lake 17.66 17.95 18.25 16.86 6.26% LongerUpper Lake Boundary 6.92 6.99 7.05 6.55 6.45% LongerLucerne Upper Lake 16.36 16.58 16.78 15.02 9.88% LongerSR 53 Lucerne 14.84 15.03 15.20 13.12 13.53% LongerLower Lake SR 53 9.10 9.21 9.31 10.14 9.60% ShorterMiddletown Lower Lake 22.28 22.42 22.57 19.96 11.60% LongerKelseyville Upper Lake 16.28 16.54 16.81 17.31 4.57% ShorterLower Lake Kelseyville 18.15 18.55 19.02 16.82 9.81% Longer

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Outline


– Curvature– Grade– Lane Width– Two-lane Highway Passing

Outline



Curvature

Curvature

Radius of 20ft, curvature of (1/20ft)*1000ft = 50 in Segment layer

Curvature

Curvature

Maximum speed is constrained by the radius

Curvature

AM PM AM PM AM PMNB 0.00% SB 0.00% NB 5.13% SB 5.13% NB 9.89% SB 9.89% NB 0.00% SB 0.00% NB 0.04% SB 0.04% NB 0.00% SB 0.00% NB 0.00% SB 0.00%

Percent with Radius < 498 ft

Effect of No Curvature on Expected Travel Time...Median 95th Percentile

SR-2

0

Mean

SR-2

9SR

-53

Boundary/Upper Lake

Upper Lake/Lucerne

Lucerne/SR 53

Upper Lake/Kelseyville

Kelseyville/Lower Lake

Lower Lake/Middletown

SR 53/Lower Lake

Curvature




SR-2

0

Mean

SR-2

9SR

-53

Boundary/Upper Lake

Upper Lake/Lucerne

Lucerne/SR 53




SR 53/Lower Lake

Curvature at which maximum speed 55 mph

Curvature




SR-2

0

Mean

SR-2

9SR

-53

Boundary/Upper Lake

Upper Lake/Lucerne

Lucerne/SR 53




SR 53/Lower Lake

Reduction in Travel Time for two pairs with most curvature

Outline



Grade

30 ft of elevation gain, from USGS DEM

Grade

1,000 ft long

Grade

3% Grade

Grade

3% Grade

Effect on Acceleration

Effect on Max. Speed

Grade

AM PM AM PM AM PMNB 1.54% SB 1.54% NB 5.40% SB 5.40% NB 4.64% SB 4.64% NB 5.39% SB 5.04% NB 26.58% SB 26.58% NB 16.37% SB 16.67% NB 16.24% SB 12.50% SR

-53

SR 53/Lower Lake

Percent with Abs. Grade > 4

SR-2

9




SR-2

0

Boundary/Upper Lake

Upper Lake/Lucerne

Lucerne/SR 53

Mean Median 95th PercentileEffect of No Grade on Population Travel Time...

Grade


-53

SR 53/Lower Lake


SR-2

9




SR-2

0

Boundary/Upper Lake

Upper Lake/Lucerne

Lucerne/SR 53


Now looking at statistics across all point-to-point Travel Times (not at simulation run level)

Grade


-53

SR 53/Lower Lake


SR-2

9




SR-2

0

Boundary/Upper Lake

Upper Lake/Lucerne

Lucerne/SR 53


Effect is opposite for uphill vs. downhill

Outline



Lane Width

Lane Width

12 ft lane

11 ft lane

10 ft lane

Lane Width

12 ft lane

11 ft lane

10 ft lane

Lane Width


SR-2

9




SR-5

3

SR 53/Lower Lake

Effect of Lane Width on Expected Travel Time...Mean Median 95th Percentile

SR-2

0

Boundary/Upper Lake

Upper Lake/Lucerne

Lucerne/SR 53

Percent with Non-12ft Lanes

Lane Width


SR-2

9




SR-5

3

SR 53/Lower Lake


SR-2

0

Boundary/Upper Lake

Upper Lake/Lucerne

Lucerne/SR 53


Back to Expected Travel Time

Lane Width


SR-2

9




SR-5

3

SR 53/Lower Lake


SR-2

0

Boundary/Upper Lake

Upper Lake/Lucerne

Lucerne/SR 53


Travel Time drops without Lane Width restriction

Outline



Two-lane Highway Passing

Two-Lane Highway Passing


-53

SR 53/Lower Lake

SR-2

9




SR-2

0

Boundary/Upper Lake

Upper Lake/Lucerne

Lucerne/SR 53

Mean Median 95th PercentilePercent with

Passing Allowed

Effect of No Passing on Population Travel Time...



-53

SR 53/Lower Lake

SR-2

9




SR-2

0

Boundary/Upper Lake

Upper Lake/Lucerne

Lucerne/SR 53


Passing Allowed


Now looking at statistics across all point-to-point Travel Times (not at simulation run level)



-53

SR 53/Lower Lake

SR-2

9




SR-2

0

Boundary/Upper Lake

Upper Lake/Lucerne

Lucerne/SR 53


Passing Allowed


• Generally increases travel time, as expected• Exceptions are due to network effects

Conclusion

Lane level detail is essential for accurate modeling of rural and exurban regions

Conclusion

Lane level detail is essential for accurate modeling of rural and exurban regions, and, as a corollary, microsimulation is essential for accurate modeling of rural and exurban regions

Thank you

[email protected]

Documents

Microsimulation for Rural and Exurban Regions: Lake County, California