U.S. Department of Transportation Federal Highway Administration MODULE 4 Volume III – Guidelines...

U.S. Department of Transportation

Federal Highway Administration

MODULE 4

Volume III – Guidelines for Applying Microsimulation Modeling

Software

2U.S. Department of Transportation


VOLUME III

● Recommend a project management process applicable to all traffic studies regardless of tool used.

● Provide overview of Project Management Process using a Microsimulation Example

● Discuss the importance of model calibration● Share examples and experiences



GOALS OF A GOOD MODELING PROCESS

● Based on a clearly defined purpose and objective● Develop consensus

– Elected officials, transportation officials and citizens

● Identify trade-offs - better decision making● Measure performance of alternatives

– Do they meet general goals of the project.

● Improve design and evaluation time and costs



PROJECT MANAGEMENT PROCESS

● Scope Project (Purpose, scope and approach)● Data Collection● Base Model Development● Error Checking● Calibration (Compare model MOE’s to field data)● Alternative Analysis● Final Report and Technical Documentation



Handout



Courtesy of MNDOT



TYPICAL QUESTIONS TO CONSIDER

● How should the project scope and physical limits be established?

● What are the project objectives?● Which traffic analysis tool is best?● How do I pick a traffic analysis tool?● What are the available resources?● Is sufficient expertise available to develop the

model?



SCOPE PROJECT

● Identify Project Purpose and Need– High Level Planning– Detailed Design– Operational

Improvements



SCOPE PROJECT

● Identify Limits of Project– Physical Construction– Operational Area of Influence– Model Limits?

● Estimate Data Collection– Available Data Sources– Additional Data Needs– Analysis Year(s) and Time

Period(s)● Estimate Level of Effort

– Commensurate to Purpose and Need, Investment, and Safety or Failure Risk

Figure Courtesy of MNDOT



PROJECT SCOPETHE REVIEWING AGENCY’S POSITION

● Have needs and expectations been met?● Have appropriate project tasks and deliverables

been identified? Is there a focus on documentation, including the

model development process and calibration process?

Have the needs of the target audience been identified?



QUESTIONS ON PROJECT SCOPE AND MODEL SELECTION

● Discuss what was considered in the selection of the microsimulation tool.

● Does the scope of work reflect these considerations?

● Will the scope of work generate a report that is soundly supported by model results that we can base engineering decisions on?

● Any additional questions?



DATA COLLECTION

● The Quality of the Data Will Influence Analysis● Use Data Which is Measurable in the Field



DATA COLLECTION

● Base Mapping– Institutionally Acceptable– Eases any Referenced to other Activities

● Field Review– Identify Hot Spots– Confirm Operations / Timing Sheets– Confirm Geometry / “Ad-hock” Lanes



DATA COLLECTION

● Traffic Volumes– Peak Periods

● Could be > 1 hr● Saturated Conditions – consider periods before / after

peak

– Turning Movements– 15 minute intervals, (or available interval)– Data should be no more than 2 years olds– Balance Counts – Influences the Outcome



GEOMETRIC DATA

Source: Introduction to CorsimTraining Course

Workshop 3

● Lane widths● Speeds● Length of accel/decel

lanes● Length of turn bays● Exclusive turn

movements



CONTROL DATA

● Actuation/Pre-timed● Phase Operations● Green times● Vehicle extensions

Source: Introduction to CorsimTraining Course

Workshop 5



DATA FOR CALIBRATION

● Depending on the Scope of the Project, Two or More of the Following Are Needed :• Mainline Volumes (Every X Feet)• Mainline Speeds (Every X Feet)• Travel Times (Link or Between Occupancy/Density

Pairs)• Bottleneck Capacity (Measured, Not Theoretical)• Entrance Ramp Queues• Intersection Queues and Queue Discharge Rates

Source: Chapter 9 Model CalibrationJohn Hourdakis, Center for Transportation Studies

University of Minnesota



FIELD OBSERVATIONS

● Verify Geometry– Has road been widened?– Have lanes been added?– Have movements been

restricted?● Verify Signal Phasing/Timing

– Do signals operate as documented?

● Verify Speed Limits– Posted speeds– Prevailing speeds



DATA COLLECTION

● Sources of Data / Studies– Instrumented Systems (TMC / TOC/Temp “RTMS”)– Planning / Permanent Count Stations– Automatic Vehicle Location / Identification Systems– Crash Databases– Manual Counts– Speed Studies– Queue Observations– O-D Studies– Truck/Freight Data



QUESTIONS ON DATA COLLECTION

● Is the necessary data available?● Does additional data need to be collected?● What resources are available for data collection in

a timely manner?● Have any data assumptions been made and have

these assumptions been documented?



BASE MODEL DEVELOPMENT

● Use Structured / Consistent Process● Information Management – Establish QA/QC

– Potential Volume– Means to Trace Input, Output and Errors– Spreadsheets– Schematics and Images– Text Files– Automated Programs – Node Numbering Convention– Assumptions




● Each Tool Is Different● Follow Recommendations of Developer● Capitalize on the Capabilities of the Tool● Multiple Parameters Include

– Driver Behavior– Vehicle Characteristics

● Consider Limitations of the Tool




● Develop Link-Node Diagram and Lane Schematic

Figure Courtesy of MNDOT




● Placement of Nodes Will Influence Output (Measure of Effectiveness)

1500’

Lane 2Lane 1

Direction of travel

1500’

Please Be Aware




● Code Network – Inputs Vary by Model– Link – Node Diagram– Traffic Volume– Origin – Destination– Turn Volume / Percentage– Signal Timing / Operational Characteristics

Variations During Analysis Period?




● Code Network – Inputs Vary by Model– Link – Node Diagram– Traffic Volume– Origin – Destination– Turn Volume / Percentage– Signal Timing / Operational Characteristics

May Warrant Multiple Time Intervals




● Develop Input for for Multiple Time Intervals

● 15 Min Intervals Link

SBL SBT SBR DIAG WBL WBT WBR DIAG WBL WBT WBR DIAG NBL NBT NBR DIAG

7:00 2 211 46 64 0 10 28 22 5 54 33 49 18

7:15 2 233 55 51 0 8 30 28 5 75 46 59 16

7:30 1 212 52 78 0 15 46 26 9 75 41 60 19

7:45 1 217 47 81 0 13 45 26 12 77 48 69 19

8:00 4 155 44 79 0 11 41 20 7 53 45 64 17

8:15 5 139 47 80 0 14 42 18 5 71 31 84 28

8:30 5 146 39 51 0 10 26 17 6 37 35 80 29

8:45 3 146 30 52 0 11 38 15 2 28 33 66 18

16:00 5 130 24 79 0 16 114 6 1 36 60 183 26

16:15 6 126 20 65 0 17 122 6 6 40 53 179 25

16:30 10 113 20 62 0 20 109 5 10 29 53 199 36

16:45 6 110 16 75 0 15 142 5 5 25 55 200 21

17:00 7 116 22 85 0 10 121 16 11 42 41 198 16

17:15 3 130 16 89 0 19 134 13 6 33 37 183 26

17:30 6 136 14 58 0 22 103 14 6 30 43 175 38

17:45 3 117 30 79 0 20 128 19 4 34 48 180 28

Rice St.

900-901905-901 906-901 908-901

694 WB ExitRice St. Vadnais Blvd.




● Run Model with Multiple Time Interval Data● What About Multiple Runs?




Why Multiple Runs?CORSIM is a stochastic model, which means that random numbers are assigned to driver and vehicle characteristics and to decision making processes. The MOEs that are obtained from a simulation are the result of a specific set of random number seeds. For example, one set of random number seeds may result in three very conservative drivers driving side by side on a three-lane roadway blocking more aggressive drivers behind them. The resulting MOE would reflect a lower average speed then has been observed in the real world. Relying on the MOE generated from a single run of CORSIM may be misleading. To gain a better understanding of network performance the network should be simulated several times using different sets of random number seeds. The resulting distribution of MOEs should then be an accurate representation of the network performance

– TSIS Users Guide




Why Multiple Runs?

For serious simulation applications, it is recommended that multiple runs be performed with different random number seeds… The MOEs can then be averaged with some clever spreadsheet manipulations.

– SimTraffic Users Guide



QUESTIONS ON BASE MODEL DEVELOPMENT

● How does the coding of the network affect the output?● Do we need to make any assumptions or do we need

additional data?● Does the existing/base year model reflect the geometric

and operational characteristics of those seen in the field?● Are the limits of the simulated network broad enough to

capture the effect of the alternatives in question?



ERROR CHECKING

● Review Input Data● Check basic network connectivity for consistency● Review Vehicle Characteristics and Performance

Data● Review Turning Movements● Review Traffic Signal Operations



ERROR CHECKING

● Run Model at Low Volume / Short Time Period● Review Animation to Confirm Geometry● Review Animation to Confirm Operations

– Single vehicle– Low volume– Full volume

● Review Model Warnings and Errors



ERROR CHECKING

Upon Completion of Base Model Development, Including Assessment with Multiple Runs

YOU HAVE A WORKING MODEL



QUESTIONS ON ERROR CHECKING

● What process should be used to identify and correct errors during base model development?

● What type of internal QA/QC process was used to assure all errors were identified?



BREAK



WHY CALIBRATE?

● Computers Cannot Magically Replicate Reality!– Simulation Models Are Designed to be General– Driver Behavior and Road Characteristics Depend on

● Location i.e. Minnesota vs California● Vehicle Characteristics (Horsepower, Size, etc.)● Weather Conditions (Dry, Wet, Ice, etc.)

● Microscopic Simulators Can Adapt and Replicate Almost Any Condition if the Model Parameters Are Properly Adjusted

– What is Realistic and What is Not?





OBJECTIVE OF CALIBRATION

To improve the ability of the model to accurately reproduce

local traffic conditions.



COMPARE MODEL TO FIELD DATA

● Calibration of Existing Models– Sometimes Referred to as Existing Condition

● Base Model is Calibrated When:– Volume, Density and other Operational Observations

are Satisfactorily Replicated– Statistical Tests Support Such a Determination



ADJUST PARAMETERS

● Calibration Involves:– Modification of Default Values (Parameters)– Consideration of the Sensitivity of Parameters– Reliance on a Sound Base Model– Representative Field Data



ADJUST PARAMETERS

● Suggestions– Limit the Modification of Multiple Parameters per

Iteration and document changes between runs– Modify Known Global and Link Level Parameters – Consider Impact of Global Parameters on Individual

Links– Consider Impact of Link Parameters on Upstream and

Downstream Locations– Use Caution When Modifying Unknown Parameters– Carefully Note all Parameter Modifications



ADJUST PARAMETERS

● Sample Global Parameters– Vehicle Entry Headway– Fleet Composition– Driver Behavior

● Sample Link Parameters– Free Flow Speed– Warning Sign Locations– Mean Start Up Delay




● What is Satisfactory?– A statistical test is suggested– Volumes Match– Density/Occupancy Match– Speeds Match– Field Observations Occur in Model– “False” bottlenecks are cleared

● Post Processor● Spreadsheets



CALIBRATION ISSUES

● Very Important For Model Accuracy and Robustness● Accuracy Depends on Measurement Granularity

– Averages Over Several Days is a Bad Choice– Might Need Additional Information to be Collected in Turbulent

Sections (Bottlenecks, Weaving Areas, etc.)

● Simulation Objective Affects Calibration– When Adaptive Control Strategies Are Simulated, Stricter

Calibration is Needed– Modeling of an Isolated Interchange in Rural Minnesota Will be

Restrictive





CALIBRATION ISSUES

● CAN BE TIME CONSUMMING PROCESS– Currently Simulators Do Not Provide a Methodology or Tools to

Assist in Calibration– Often Users End Up in Endless Trial-and-Error Cycles– Sporadic Attempts Made in Literature to Streamline the Process

But:● Focused on a Particular Simulator● Too Complex or too Naive to be Effectively Used in Practice● No Widely Accepted Methods/Standards Currently Available





BEFORE CALIBRATION!

● Check Geometry For Correctness– Disjoined Sections– Stuck Vehicles (Sizes of Accel/Decel Lanes)– Verify Location of Detectors

● Check Input For Accuracy– Entrance Volume Comparison (Perfect Match)– Exit Volume Comparison (Match Sum Over All Hours)– Volume Totals on Mainline Stations Should Match






● Once Existing Condition is Calibrated– Reflect Calibration Data in Alternatives Analysis– May Proceed with Alternatives Analysis



I-494 SOUTHBOUND CALIBRATION EXAMPLE

● CORSIM Model Developed to Evaluate:– I-494 Expansion From TH 5 to TH 55– I-394 Interchange Modification

● Model limits– I-494 From Fish Lake Interchange (I-94) to Valley View Road– I-394 From Central Avenue to TH 169/General Mills Interchange– 17 Service Interchanges– 3 Systems Interchanges

Source: Chapter 9 Corsim CalibrationJaimison Sloboden, P.E.,

Short Elliot Hendrickson, Inc.



SB I-494 TRY 1From To

Node From

NodeTo

Receiv-ing

NodeLength Speed

107 SB I-494 WB I-94/694 On Ramp 300 310 311 1028 65 100108 WB I-94/694 On Ramp 310 311 312 1604 65 100109 311 312 313 2021 65 100110 312 313 314 1917 65 100111 Bass Lake Road Off Ramp 313 314 315 1535 65 100112 Bass Lake Road Off Ramp 314 315 316 1289 65 100113 Bass Lake Road On Ramp 315 316 317 1368 65 100114 Bass Lake Road On Ramp 316 317 318 1399 65 100115 317 318 319 2076 65 100116 318 319 320 1495 65 100117 319 320 321 1719 65 100118 320 321 322 1570 65 100119 321 322 323 2113 65 100120 Rockford Road Off Ramp 322 323 324 1180 65 100121 Rockford Road Off Ramp 323 324 325 1077 65 100122 Rockford Road On Ramp 324 325 326 1015 65 100123 Rockford Road On Ramp 325 326 327 1447 65 100124 326 327 328 1547 65 100125 TH 55 Off Ramp 327 328 329 1341 65 100126 TH 55 Off Ramp 328 329 330 1199 65 100127 TH 55 On Ramp 329 330 331 1227 65 100128 TH 55 On Ramp 330 331 332 927 65 100129 331 332 333 1096 65 100130 County Road 6 Off Ramp 332 333 334 804 65 100131 County Road 6 Off Ramp 333 334 335 1244 65 100132 County Road 6 On Ramp 334 335 336 1176 65 100133 County Road 6 On Ramp 335 336 337 971 65 100134 Carlson Parkway Off Ramp 336 337 338 1022 65 100135 Carlson Parkway Off Ramp 337 338 339 1635 70 100136 Carlson Parkway On Ramp 338 339 340 1545 70 100137 Carlson Parkway On Ramp 339 340 341 747 70 100138 WB I-394 Off Ramp 340 341 342 771 70 100139 WB I-394 Off Ramp WB I-394 On Ramp 341 342 343 1291 70 100140 WB I-394 On Ramp EB I-394 Off Ramp 342 343 344 392 70 100141 EB I-394 Off Ramp EB I-394 On Ramp 343 344 345 1117 70 100142 EB I-394 On Ramp 344 345 346 1508 70 100143 345 346 347 1500 70 100144 346 347 348 1499 70 100145 347 348 349 1100 70 100146 348 349 350 1501 70 100147 Minnetonka Blvd Off Ramp 349 350 360 1510 70 100148 Minnetonka Blvd Off Ramp Minnetonka Blvd On Ramp 350 360 361 975 70 100149 Minnetonka Blvd On Ramp 360 361 362 1670 70 100150 361 362 363 1755 70 100151 WB TH 7 Off Ramp 362 363 364 1502 70 100152 WB TH 7 Off Ramp WB TH 7 On Ramp 363 364 365 1310 70 100153 WB TH 7 On Ramp EB TH 7 Off Ramp 364 365 366 292 70 100154 EB TH 7 Off Ramp EB TH 7 On Ramp 365 366 367 1058 70 100155 EB TH 7 On Ramp 366 367 368 1474 70 100156 367 368 369 1465 70 100157 368 369 370 1487 70 100158 369 370 371 960 70 100159 370 371 372 1503 70 100160 371 372 373 1500 70 100161 TH 62 Off Ramp 372 373 374 1893 70 100162 TH 62 Off Ramp 373 374 375 1045 70 100163 TH 62 On Ramp 374 375 376 1045 70 100164 TH 62 On Ramp 375 376 377 975 70 100165 376 377 378 1505 70 100166 377 378 379 1071 70 100167 378 379 380 1120 70 100168 Valley View Road Off Ramp 379 380 381 1499 70 100169 Valley View Road Off Ramp SB I-494 380 381 8381 1566 70 100

SO

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HB

OU

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I-49

4

Link Description Link Geometrics CarFollow-

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1 2 3 4 5 6 7 8 9 10 11 12

334-335Actual (detected) SpeedSimulated Speed

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1 2 3 4 5 6 7 8 9 10 11 12


0

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•Default Car Following Factors

•Estimated Free Flow Speeds


Short Elliot Hendrickson, Inc.Handout



SB I-494 TRY 12From To

Node From

NodeTo

Receiv-ing

NodeLength Speed

176 SB I-494 WB I-94/694 On Ramp 300 310 311 1028 70 100177 WB I-94/694 On Ramp 310 311 312 1604 70 105178 311 312 313 2021 70 105179 312 313 314 1917 70 100180 Bass Lake Road Off Ramp 313 314 315 1535 70 100181 Bass Lake Road Off Ramp 314 315 316 1289 70 100182 Bass Lake Road On Ramp 315 316 317 1368 70 100183 Bass Lake Road On Ramp 316 317 318 1399 70 100184 317 318 319 2076 70 100185 318 319 320 1495 70 100186 319 320 321 1719 70 100187 320 321 322 1570 70 100188 321 322 323 2113 70 100189 Rockford Road Off Ramp 322 323 324 1180 70 100190 Rockford Road Off Ramp 323 324 325 1077 70 100191 Rockford Road On Ramp 324 325 326 1015 70 100192 Rockford Road On Ramp 325 326 327 1447 70 100193 326 327 328 1547 70 100194 TH 55 Off Ramp 327 328 329 1341 70 100195 TH 55 Off Ramp 328 329 330 1199 70 100196 TH 55 On Ramp 329 330 331 1227 70 100197 TH 55 On Ramp 330 331 332 927 70 100198 331 332 333 1096 70 100199 County Road 6 Off Ramp 332 333 334 804 70 100200 County Road 6 Off Ramp 333 334 335 1244 65 100201 County Road 6 On Ramp 334 335 336 1176 65 130202 County Road 6 On Ramp 335 336 337 971 65 130203 Carlson Parkway Off Ramp 336 337 338 1022 65 130204 Carlson Parkway Off Ramp 337 338 339 1635 65 130205 Carlson Parkway On Ramp 338 339 340 1545 65 130206 Carlson Parkway On Ramp 339 340 341 747 65 130207 WB I-394 Off Ramp 340 341 342 771 65 130208 WB I-394 Off Ramp WB I-394 On Ramp 341 342 343 1291 65 130209 WB I-394 On Ramp EB I-394 Off Ramp 342 343 344 392 65 100210 EB I-394 Off Ramp EB I-394 On Ramp 343 344 345 1117 65 100211 EB I-394 On Ramp 344 345 346 1508 65 100212 345 346 347 1500 65 100213 346 347 348 1499 65 100214 347 348 349 1100 65 120215 348 349 350 1501 65 120216 Minnetonka Blvd Off Ramp 349 350 360 1510 70 120217 Minnetonka Blvd Off Ramp Minnetonka Blvd On Ramp 350 360 361 975 70 120218 Minnetonka Blvd On Ramp 360 361 362 1670 70 100219 361 362 363 1755 70 100220 WB TH 7 Off Ramp 362 363 364 1502 70 100221 WB TH 7 Off Ramp WB TH 7 On Ramp 363 364 365 1310 70 100222 WB TH 7 On Ramp EB TH 7 Off Ramp 364 365 366 292 70 100223 EB TH 7 Off Ramp EB TH 7 On Ramp 365 366 367 1058 70 100224 EB TH 7 On Ramp 366 367 368 1474 70 100225 367 368 369 1465 70 100226 368 369 370 1487 70 100227 369 370 371 960 70 100228 370 371 372 1503 70 100229 371 372 373 1500 70 100230 TH 62 Off Ramp 372 373 374 1893 70 100231 TH 62 Off Ramp 373 374 375 1045 70 100232 TH 62 On Ramp 374 375 376 1045 70 100233 TH 62 On Ramp 375 376 377 975 70 100234 376 377 378 1505 70 100235 377 378 379 1071 70 100236 378 379 380 1120 70 100237 Valley View Road Off Ramp 379 380 381 1499 70 100238 Valley View Road Off Ramp SB I-494 380 381 8381 1566 70 100

Link Description Link Geometrics CarFollow-

ingFactor

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I-49

4

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0

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1 2 3 4 5 6 7 8 9 10 11 12

334-335

Actual (detected)SpeedSimulated Speed

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1 2 3 4 5 6 7 8 9 10 11 12


0

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•Car Following Factors Modified

•Free Flow Speeds Modified





I-494 SOUTHBOUND MOE’S

TH 55 Off Ramp 328 329 1,199 3,199 3,160 -39 64 24 C 9,389 9,358 -31TH 55 On Ramp 329 330 1,227 3,199 3,160 -39 65 24 C 65 24 C 9,389 9,361 -28

TH 55 On Ramp 330 331 927 3,865 3,815 -50 63 20 B 11,627 11,592 -35331 332 1,096 3,865 3,818 -47 66 19 B 65 19 B 11,627 11,595 -32

County Road 6 Off Ramp 332 333 804 3,865 3,819 -46 66 17 B 11,627 11,596 -31County Road 6 Off Ramp 333 334 1,244 3,429 3,405 -24 62 18 B 10,445 10,413 -32

County Road 6 On Ramp 334 335 1,176 3,429 3,408 -21 60 19 B 61 18 B 10,445 10,410 -35County Road 6 On Ramp 335 336 971 3,817 3,823 6 55 20 C 11,639 11,587 -52

Carlson Parkway Off Ramp 336 337 1,022 3,817 3,841 24 48 28 C 51 24 C 11,639 11,589 -50Carlson Parkway Off Ramp 337 338 1,635 2,812 2,984 172 45 42 E 9,660 9,646 -14

Carlson Parkway On Ramp 338 339 1,545 2,812 3,014 202 37 58 F 41 50 F 9,660 9,645 -15Carlson Parkway On Ramp 339 340 747 3,156 3,365 209 29 54 F 10,340 10,327 -13

WB I-394 Off Ramp 340 341 771 3,156 3,377 221 27 55 F 28 54 F 10,340 10,324 -16WB I-394 Off Ramp WB I-394 On Ramp 341 342 1,291 2,985 3,228 243 27 73 F 9,740 9,731 -9WB I-394 On Ramp EB I-394 Off Ramp 342 343 392 3,373 3,595 222 19 76 F 10,884 10,798 -86EB I-394 Off Ramp EB I-394 On Ramp 343 344 1,117 2,839 3,058 219 18 103 F 8,842 8,810 -32EB I-394 On Ramp 344 345 1,508 3,829 4,022 193 30 61 F 11,341 11,267 -74

345 346 1,500 3,829 4,022 193 39 55 F 11,341 11,263 -78346 347 1,499 3,829 4,022 193 31 68 F 11,341 11,258 -83347 348 1,100 3,829 4,023 194 40 50 F 42 50 F 11,341 11,251 -90348 349 1,501 3,829 4,023 194 54 37 E 11,341 11,242 -99

Minnetonka Blvd Off Ramp 349 350 1,510 3,829 4,028 199 59 31 D 11,341 11,234 -107Minnetonka Blvd Off Ramp Minnetonka Blvd On Ramp 350 360 975 3,566 3,775 209 59 33 D 10,541 10,452 -89Minnetonka Blvd On Ramp 360 361 1,670 3,912 4,114 202 53 31 D 11,273 11,185 -88

361 362 1,755 3,912 4,115 203 60 34 D 59 32 D 11,273 11,178 -95WB TH 7 Off Ramp 362 363 1,502 3,912 4,117 205 63 30 D 11,273 11,173 -100

WB TH 7 Off Ramp WB TH 7 On Ramp 363 364 1,310 3,573 3,770 197 62 30 D 10,151 10,089 -62WB TH 7 On Ramp EB TH 7 Off Ramp 364 365 292 3,637 3,830 193 55 24 C 10,295 10,226 -69EB TH 7 Off Ramp EB TH 7 On Ramp 365 366 1,058 3,334 3,555 221 54 37 E 9,496 9,497 1EB TH 7 On Ramp 366 367 1,474 3,969 4,175 206 47 38 E 11,179 11,158 -21

367 368 1,465 3,969 4,173 204 60 34 D 11,179 11,148 -31368 369 1,487 3,969 4,170 201 62 34 D 11,179 11,143 -36369 370 960 3,969 4,168 199 62 33 D 59 34 D 11,179 11,138 -41370 371 1,503 3,969 4,174 205 56 37 E 11,179 11,129 -50371 372 1,500 3,969 4,178 209 62 33 D 11,179 11,115 -64

TH 62 Off Ramp 372 373 1,893 3,969 4,179 210 62 30 D 11,179 11,107 -72

TH 55 Off Ramp 328 329 1,199 3,199 3,205 6 61 26 C 9,389 9,469 80TH 55 On Ramp 329 330 1,227 3,199 3,203 4 61 26 C 61 26 C 9,389 9,475 86

TH 55 On Ramp 330 331 927 3,865 3,848 -17 60 21 C 11,627 11,729 102331 332 1,096 3,865 3,850 -15 62 21 C 61 20 C 11,627 11,730 103

County Road 6 Off Ramp 332 333 804 3,865 3,852 -13 61 19 B 11,627 11,738 111County Road 6 Off Ramp 333 334 1,244 3,429 3,441 12 61 18 B 10,445 10,539 94

County Road 6 On Ramp 334 335 1,176 3,429 3,444 15 62 18 B 61 18 B 10,445 10,535 90County Road 6 On Ramp 335 336 971 3,817 3,840 23 59 18 B 11,639 11,732 93

Carlson Parkway Off Ramp 336 337 1,022 3,817 3,841 24 60 21 C 60 20 C 11,639 11,728 89Carlson Parkway Off Ramp 337 338 1,635 2,812 2,966 154 64 21 C 9,660 9,757 97

Carlson Parkway On Ramp 338 339 1,545 2,812 2,979 167 57 29 D 61 25 C 9,660 9,756 96Carlson Parkway On Ramp 339 340 747 3,156 3,343 187 46 33 D 10,340 10,443 103

WB I-394 Off Ramp 340 341 771 3,156 3,360 204 40 40 E 43 37 E 10,340 10,440 100WB I-394 Off Ramp WB I-394 On Ramp 341 342 1,291 2,985 3,220 235 26 74 F 9,740 9,834 94WB I-394 On Ramp EB I-394 Off Ramp 342 343 392 3,373 3,597 224 16 82 F 10,884 10,883 -1EB I-394 Off Ramp EB I-394 On Ramp 343 344 1,117 2,839 3,090 251 14 106 F 8,842 8,837 -5EB I-394 On Ramp 344 345 1,508 3,829 4,081 252 32 55 F 11,341 11,307 -34

345 346 1,500 3,829 4,088 259 59 35 D 11,341 11,300 -41346 347 1,499 3,829 4,091 262 61 34 D 11,341 11,296 -45347 348 1,100 3,829 4,092 263 62 33 D 56 37 E 11,341 11,295 -46348 349 1,501 3,829 4,100 271 63 33 D 11,341 11,285 -56

Minnetonka Blvd Off Ramp 349 350 1,510 3,829 4,111 282 63 30 D 11,341 11,279 -62Minnetonka Blvd Off Ramp Minnetonka Blvd On Ramp 350 360 975 3,566 3,839 273 63 30 D 10,541 10,457 -84Minnetonka Blvd On Ramp 360 361 1,670 3,912 4,192 280 54 31 D 11,273 11,185 -88

361 362 1,755 3,912 4,189 277 61 34 D 59 32 D 11,273 11,181 -92WB TH 7 Off Ramp 362 363 1,502 3,912 4,189 277 62 30 D 11,273 11,175 -98

WB TH 7 Off Ramp WB TH 7 On Ramp 363 364 1,310 3,573 3,848 275 56 37 E 10,151 10,083 -68WB TH 7 On Ramp EB TH 7 Off Ramp 364 365 292 3,637 3,906 269 50 30 D 10,295 10,228 -67EB TH 7 Off Ramp EB TH 7 On Ramp 365 366 1,058 3,334 3,625 291 48 47 F 9,496 9,497 1EB TH 7 On Ramp 366 367 1,474 3,969 4,243 274 45 41 E 11,179 11,150 -29

367 368 1,465 3,969 4,246 277 61 34 D 11,179 11,146 -33368 369 1,487 3,969 4,245 276 62 34 D 11,179 11,142 -37369 370 960 3,969 4,247 278 60 35 E 58 35 E 11,179 11,141 -38370 371 1,503 3,969 4,241 272 55 38 E 11,179 11,138 -41371 372 1,500 3,969 4,241 272 62 34 D 11,179 11,128 -51

TH 62 Off Ramp 372 373 1,893 3,969 4,237 268 61 32 D 11,179 11,115 -64

Try 1 MOE’s

Try 12 MOE’s





QUESTIONS ON CALIBRATION

● Were multiple runs used to calibrate the model?– Why or why not?

● Was the calibration process documented, including what parameters were modified and why?

● Why were default parameters modified and how was the user specified value selected?



ALTERNATIVES ANALYSIS

● Why do we conduct an Alternatives Analysis?– Environmentally required– Looking for best operational strategy– What is the purpose?

● What do we consider?– Assess No-Build and Build Concepts– Design Year, Mid-Year(s), Opening Year and Existing Year– What else?



ALTERNATIVE ANALYSIS

● Amount of Output Can Be Overwhelming● Convey Characteristics of Alternative

– Highlight Problem Areas– Highlight Opportunity

● Utilize Tabular Summaries● Utilize Animation● Utilize Schematics




● Reflect Upon the No-Build with Build Alternatives● A “Relative Comparison” Normalizes Output● Consider Impacts of Geometric and Operational Strategies● Baseline Demand Forecast● Capacity constraint, uncertainty.● Selection of MOE’s● Multiple Replications● Correcting Biases with Results● Comparison to HCM



Discussion of Examples



● Step 1: Baseline Demand Forecast– 5-year forecast was estimated – assumed straight line growth– 2% per year uncompounded– 10% increase for the corridor– No anticipated capacity constraints

● Step 2: Generation of Alternatives– 2 alternatives test – No Build and Build– Build alternative – ramp metering on the 2 eastbound freeway

on-ramps– No-Build alternative – no ramp metering




● Step 3: Selection of MOEs– MOEs selected for evaluation

● VMT● VHT● Delay (vehicle-hours)● Selected indicator – blocked link● Report mean results rather than 95% worst case result




● Step 4: Model Application– Run model 10 times for each

alternative– Impact on ramp meters on

route choice estimated outside the model

– Manually adjusted turn percentages

– Induced demand not considered to be a significant factor

– Signal/meter optimization performed outside model

– Separate optimizations performed for each alternative




● Step 5: Tabulation of Results– 10 repetitions of each alternative– Output to a spreadsheet and averaged– Post-model corrections not necessary

● No increasing queues of underserved demand found




● Step 6: Evaluation of Alternatives– No Build Scenario

● Corridor delay increased 46% over existing conditions● VMT increased 12%● Total travel time increased 20%● Delay increases on freeway mainline links

– Build Scenario● Delay – 3% less than No-build alternative● Slight increase in VMT● Freeway mainline improved – at expense of on-ramp traffic● Improvements operationally acceptable




POINTS / QUESTIONS ON ALTERNATIVE ANAYLSIS

● LOS results should not be derived from microsimulation output– Address this Early in Scoping Process

● Did the alternatives analysis focus on numerical output or by viewing the animation?

● How was the preferred alternative selected?– What are the operational benefits?



FINAL REPORT

● Measures of Effectiveness – Each Tool May Be Slightly Different– Difference in HCM Methodology

● Utilize Animation ● Convey Analysis Results● Explain Measure of Effectiveness● Capitalize on the Relative Comparison



FINAL REPORT

● Address the Original Question / Problem● Tie Back to the Purpose and Need● Clarify the Geometric Modifications● Clarify the Operational Strategy● Identify the Operational Area of Influence



QUESTIONS ON THE FINAL REPORT

● Does the final report address the needs of the target audience?

● Do the reported numerical values have meaning to the target audience?

● Does the simulated analysis support the engineering decision?



Summary

● Traffic Analysis Tools Program● Traffic Analysis Toolbox

– Volume I – Primer– Volume II– Volume III

● Project Scoping in context of microsimulation● Applying Guidelines to Microsimulation

U.S. Department of Transportation Federal Highway Administration MODULE 4 Volume III – Guidelines...

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