1. 1 Presented at 2008 North American Paramics User Group Meeting 1 Evaluation of Incorporating Hybrid Vehicle Use of HOV Lanes Lianyu Chu CLR Analytics Inc July 14, 2008 @ NA Paramics User Group Meeting

2. 2 Presented at 2008 North American Paramics User Group Meeting 2 Background Many states have demonstrated the effectiveness of HOV lanes HOV lane operation is criticized –Underutilization of roadway capacity –Limited ability to shift solo drivers to transit and carpools Conversion to other type of operation –Allowing single occupant hybrid vehicles (SOHV) –In southern California From buffer separate to continuous access –HOT

3. 3 Presented at 2008 North American Paramics User Group Meeting 3 HOV lanes What is HOV lane? Northern CA –Continuous access –Operated during peak periods –HOV 2+ or 3+ Southern CA –Limited access –Operated 24 hours a day –HOV 2+ HOV lanes in CA –About 30% of the total of US

4. 4 Presented at 2008 North American Paramics User Group Meeting 4 Current Hybrid HOV policy in California Starting Jan 2005 –Stickers will expire in 2010. Vehicle models > 45 miles per gallon –Toyota Prius –Hybrid Honda Civic –Honda Insight Maximum number of stickers –Originally, 75K, reached at Nov 2006 –Then, decided to offer 10K more Reaches 85K on 2/2/2007 –No more stickers

5. 5 Presented at 2008 North American Paramics User Group Meeting 5 Motivation Statewide policy –San Francisco Bay Area there is substantial reserve capacity on HOV lanes –Orange County, HOV lanes have almost reached their nominal capacity of 1,650 vehicles per hour, carrying an average of 1,568 vph in 1998 Purpose: –Investigate impacts of the policy in OC Operational effects Emission effects

6. 6 Presented at 2008 North American Paramics User Group Meeting 6 Study Network

7. 7 Presented at 2008 North American Paramics User Group Meeting 7 Socio-economic characteristics & Hybrid Population Data Policy Design scenario Estimate hybrid demand Select study site Build micro-simulation model in Paramics Calibrate micro- simulation model Run simulation for each scenario Performance measures Estimate SOV / HOV demand Planning model Compare simulation results Policy Implications Methodology

8. 8 Presented at 2008 North American Paramics User Group Meeting 8 Model All major freeways –I-5, I-405, SR-55, SR-22, SR-57, and SR-91 –Most freeway mainline have 4-6 lanes –Excluding 6-mile the southern part of I-5, the section of SR-91 express lane. Model summary –200 HOV lane miles –800 mainline lane miles Total zones: 265 AM Peak hour model

9. 9 Presented at 2008 North American Paramics User Group Meeting 9 HOV lane modeling Network construction (buffer-separated HOV) –The mixed-flow lanes and HOV lanes were coded as two separate links wherever required. –Non-buffered sections were coded as a single link between ingress and egress points. Route choice models –Combination of the use of three routing models All-or-nothing Stochastic route choice Dynamic feedback

10. 10 Presented at 2008 North American Paramics User Group Meeting 10 Model calibration Calibration data preparation and data analysis Initial calibration / setting of route choice models OD demand estimation Network performance calibration and validation Final model Route choice modification

11. 11 Presented at 2008 North American Paramics User Group Meeting 11 Calibration data preparation Base year: 2005 –Both flow and speed data were collected from PeMS Flow data: –Gather data from four different years (2002-2005) –Some on-ramp and off-ramp locations estimated based on Caltrans census dataset or mainline data Speed data –5-min speed data were collected from freeways for 3 months –Draw the 50th percentile speed contour maps based on Tuesday to Thursday’s data –Used to identify freeway bottlenecks.

12. 12 Presented at 2008 North American Paramics User Group Meeting 12 Demand Estimation Pattern OD matrix –OCTAM: planning model of Orange County, CA –Extracted using MMA analysis in TransCAD Fine-tune OD matrix using Paramics OD estimator HOV demand estimation –A fixed percentage: 21.7% –Based on California DOT’s HOV report and loop detector data –Trial-and-error based on range from 14% to 25% Hybrid demand estimation model : –Estimate each zone’s hybrid percentage –Multinomial regression and binomial regression model Social-economic data Survey data

13. 13 Presented at 2008 North American Paramics User Group Meeting 13 HOV volume / total volume (based on 2005 D12 HOV report) Peak period (6:30 - 9:00)Peak hour (6:30-7:30) NameFreewayPM HOV volume Total volumePercentage HOV volume Total volumePercentage Los Alisos BoulevardI5 NB1843653199513.6%18831312214.3% Tustin Ranch RoadI5SBR28.358052602122.3%27411095725.0% Main StI5SB33.148072502119.2%19951062818.8% Harbor BlvdI5SB37.437542095117.9%1833909920.1% Broadway stI5SB38.743042136820.1%1785918319.4% Von KarmanI 405 NB7.428872818210.2%13201162511.4% Ward StI 405 SB13.238463009412.8%15981274912.5% Walnut AveSR 55 SB14.244921905123.6%1999860723.2% Warner AveSR 55 SBR 8.552842366522.3%23451031022.7% Yorba Linda BlvdSR 57 SB18.337291613423.1%1571678523.2% HarborSR 91 WB3.333771801818.7%1636781820.9% HOV volume / total volume percentage: –peak period: 10.2% - 23.1% –peak hour: 11.4% - 25% Patterns: –HOV lanes attract more carpoolers since HOV lane is faster –Congested areas: higher percentages

14. 14 Presented at 2008 North American Paramics User Group Meeting 14 Regression Model for Share of Hybrid Vehicles Variable Coefficientt-statistic Median Household Income /$10k0.01236411.25 Average Household Size0.0022861.46 Average Workers per Household0.0183472.96 Average Workers / Median Household Income-0.06142-2.90 Constant0.18642926.72 Number of observations62 R-squared0.9866 Root MSE0.00248

15. 15 Presented at 2008 North American Paramics User Group Meeting 15 Model Calibration/Validations Criteria and MeasuresFHWA targetsModel Performance Hourly flow: Model Vs Observed GEH Statistic – Individual Link Flows GEH < 5 > 85% of cases70% of cases Speed: Model Vs Observed Match bottleneck locationsTo analyst’s satisfactionMatched all major bottleneck locations (see graphs) Visual audits: Individual Link Speeds Visually acceptable Speed-Flow relationship Bottlenecks Visually acceptable Queuing To analyst’s satisfaction Satisfied Data for baseline model calibration - End of 2004 data from PeMS

16. 16 Presented at 2008 North American Paramics User Group Meeting 16 5NB HOV Speed Contour: Observed5NB HOV Speed Contour: Simulated

17. 17 Presented at 2008 North American Paramics User Group Meeting 17 5SB HOV Speed Contour: Observed5SB HOV Speed Contour: Simulated

18. 18 Presented at 2008 North American Paramics User Group Meeting 18 405NB HOV Speed Contour: Observed405NB HOV Speed Contour: Simulated

19. 19 Presented at 2008 North American Paramics User Group Meeting 19 405SB HOV Speed Contour: Observed 405SB HOV Speed Contour: Simulated

20. 20 Presented at 2008 North American Paramics User Group Meeting 20 55NB HOV Speed Contour: Observed55NB HOV Speed Contour: Simulated

21. 21 Presented at 2008 North American Paramics User Group Meeting 21 55SB HOV Speed Contour: Observed55SB HOV Speed Contour: Simulated

22. 22 Presented at 2008 North American Paramics User Group Meeting 22 57SB HOV Speed Contour: Observed57SB HOV Speed Contour: Simulated

23. 23 Presented at 2008 North American Paramics User Group Meeting 23 Scenario Construction Base Case: –No Hybrids allowed on HOV lanes –before California’s bill AB 2628 passed Scenario 1: –36K Hybrids in CA (Nov 2005) –3707 of 36K hybrids in OC Scenario 2: –50K Hybrids (April 2006) –5216 of 50K hybrids in OC Scenario 3: –75K Hybrids (Nov 2006) Scenario 4: –100K Hybrid (near future) ScenariosSOVHOVHybrid Base Case78.321.70.00 scenario 176.821.71.6 Scenario 276.221.72.2 Scenario 375.121.73.2 Scenario 474.021.74.3 * Total trips for study network: 238K DMV data show: -About 10% of CA hybrids are in OC

24. 24 Presented at 2008 North American Paramics User Group Meeting 24 Performance Measures Overall network performance measures: –Vehicle Hours Traveled (VHT) –Vehicle Miles Traveled (VMT) Corridor performance measures: –Average corridor speed –Speed SAFETEA-LU needs HOV lanes to keep speed higher than 45 mph for 90% of the peak periods –LOS Caltrans has the authority to remove “individual HOV lanes or portions of those lanes,” if traffic condition exceeds LOS C. Emissions & Fuel consumptions –Comprehensive Modal Emission Model (CMEM) from UC Riverside –second-by-second emissions

25. 25 Presented at 2008 North American Paramics User Group Meeting 25 HOV Segments for further analysis FreewaysDirections Distance (miles) ML sections HOV sections I-405 NB2245 SB2244 I-5 NB3477 SB3467 SR-55 NB1543 SB1533 SR-57 NB1133 SB1134 SR-91 EB834 WB833 -Total 43 HOV sections -Study period: 5minutes (for 1-hour data)

26. 26 Presented at 2008 North American Paramics User Group Meeting 26 Simulation design Assuming no HOV lane violations during simulation. Simulations period –One peak hour in AM –Simulate for 1 hour and 30 minutes. –The first 30 minutes of simulation: warm-up period MOE –Collected using different plug-ins –Only the last one hour of the simulations were analyzed. Base scenario –used as reference to evaluate other scenarios. Five runs were conducted per scenario –The results from the median run are used for analysis.

27. 27 Presented at 2008 North American Paramics User Group Meeting 27 VMTBCSC1SC2SC3SC4 BC0 SC10.30 SC20.50.40 SC30.750.60.650 SC40.980.9 0.750 Overall Network Performance VHTBCSC1SC2SC3SC4 BC0 SC10.90 SC20.9750.850 SC30.980.90.70 SC40.990.950.80.40 Confidence interval for the comparison

28. 28 Presented at 2008 North American Paramics User Group Meeting 28 Comparison of HOV & ML (I-5 & I-405)

29. 29 Presented at 2008 North American Paramics User Group Meeting 29 Comparison of HOV & ML (SR-55&57)

30. 30 Presented at 2008 North American Paramics User Group Meeting 30 Speed Distribution: HOV sections With more traffic allowed into HOV lanes, HOV lane performance degrades

31. 31 Presented at 2008 North American Paramics User Group Meeting 31 Percentage of Sections & Time periods with speed greater than 45 mph

32. 32 Presented at 2008 North American Paramics User Group Meeting 32 LOS Distribution: HOV lanes

33. 33 Presented at 2008 North American Paramics User Group Meeting 33 Percentage of Sections & Time spent less than 26 veh/mile/lane (LOS C)

34. 34 Presented at 2008 North American Paramics User Group Meeting 34 Comparison of Emissions Scenario 4 reduces emissions significantly –due to high share of Hybrids

35. 35 Presented at 2008 North American Paramics User Group Meeting 35 Policy decision: multi-objective optimization problem Maximize the benefits obtained from emission –SC4 is the best Meet FHWA’s SAFETEA-LU’s requirement. –Base-year: doesn’t meet –Practical: allow another 10% HOV lanes to be under 45 mph –SC1-3 can meet HOV lanes must continue to provide benefits for existing carpoolers. –MOE: percentage of ave. speed difference between HOV & mixed-flow lanes –Speed difference in Sc1-SC3 are 21%, 16% and 11%. –An intuitive feeling : at least 15% speed difference SC1-2 meet Scenario 2 appears likely to satisfy the desires of all stakeholders.

36. 36 Presented at 2008 North American Paramics User Group Meeting 36 Findings With the increase of Hybrids, the operational performance of HOV lanes degrades Overall, Scenario 2 performs more effectively (50K hybrid) –HOV lane speed is reduced by less than 5% in scenario 2 From air quality perspective, scenario 4 (100K hybrids) outperforms. Hybrid HOV policy may have impacted sales of Hybrid vehicles –April 2006: 50K –Nov 2006: 75K –Feb 2, 2007: 85K

37. 37 Presented at 2008 North American Paramics User Group Meeting 37 Policy Implication The policy is successful in reducing emission by allowing hybrid vehicles using HOV lanes. The policy is not appropriate to be applied to the HOV lanes that don’t have reserved capacity. 50K hybrid vehicle permits (SC2) throughout the state could be the maximum that the Orange County HOV system can take without much degradation. The policy could have been implemented more strategically, i.e. applying to selected freeways and/or selected time periods.

38. 38 Presented at 2008 North American Paramics User Group Meeting 38 Project team CCIT, UC Berkeley Lianyu Chu UC Irvine Will Recker David Brownstone Tom Golob K S Nesamani Chris Breiland Western Michigan University Jun Seok Oh

39. 39 Presented at 2008 North American Paramics User Group Meeting 39 Thank you! Questions & Comments