Operational Effect of Allowing Single Occupant Hybrid Vehicles into High Occupancy Vehicle Lanes Chris Breiland Fehr & Peers Associate Lianyu Chu, Hamed Benouar California Center for Innovative Transportation (CCIT) UC Berkeley
Dec 21, 2015
Operational Effect of Allowing Single Occupant Hybrid Vehicles into High Occupancy Vehicle Lanes
Chris BreilandFehr & Peers Associate
Lianyu Chu, Hamed BenouarCalifornia Center for Innovative Transportation (CCIT)UC Berkeley
Energy Use/Air Quality Issues
Increased Vehicle Miles Traveled
Antipathy Toward HOV Lanes
Hybrid Hype
Origins of “Hybrid-HOV” Laws
• SAFETEA-LU Requirements
– States can allow energy efficient, clean air SOVs in HOV lanes
– No operational degradation
Policy Specifics
• Implemented prior to passage of SAFTEA-LU
• Different definition of HOV lane degradation
– Primarily density/LOS based versus speed based
Policy Specifics - California AB 2628
Hybrid Population Data
PolicyDesign scenario
Estimate hybrid demand
Select study site
Build micro-simulation model
Calibrate micro-simulation model
Run simulation for each scenario
Performance measures
Estimate SOV / HOV demand
Planning model
Compare simulation results
Policy Implications
Methodology
Study Scenarios
• Baseline: Existing Conditions
• Scenario 1: Existing Hybrid Population
• Scenario 2: 50,000 Hybrid Checkpoint
• Scenario 3: 75,000 Hybrid Maximum
• Scenario 4: Eight Percent Hybrid Share
• Scenario 5: Nineteen Percent Hybrid Share
• Irvine, CA
– Highly Detectorized
– Fairly Busy
– Variety of HOV
Lane Geometries
Source: Google Maps
Study Location
Paramics Simulation Model
Paramics Simulation Model
Criteria and Measures Acceptability Targets
Model Performance
Hourly flows: modeled versus observed
Individual Link Flows Within 400 vph for flow > 2700 vph
Total (summed) Link Flows Within 5%
GEH Statistic – Individual Link Flows GEH < 5
GEH Statistic – Total (summed) Link Flows GEH < 4
> 85% of all cases All links
> 85% of all cases
All links
TOTA L: 153 mainline and ramp links
75%* Yes – Average error 3.61%
92%
Yes – Average GEH 3.17
Travel Time: modeled versus observed
Point-to-point Travel Times Within 15% or one minute, whichever is higher
> 85% of all cases
TOTA L: 6 trips
83%**
Visual Audits
Individual Link Speeds Visually acceptable speed-flow relationship
Bottlenecks Visually acceptable queuing
To analyst’s satisfaction
To analyst’s satisfaction
Acceptable Acceptable
* If criteria were expanded to allow flows of 408 or less, then 92% of cases would have been acceptable ** Due to a limited number of Caltrans travel time measurements, only six travel time comparisons can be made with 5 of the 6 trips within one minute of the measured time.
Model Calibration / Validation
• Based on California Law and Virginia HOV Task Force Report
– HCM 2000 Level of Service based on density
– Change in HOV lane travel time
– HOV lane flow rates
Performance Measures
HOV Lane Segment Performanc e Measure
Baseline Scen ario
1 Scen ario
2 Scen ario
3 Scen ario
4 Scen ario
5
Min 4.7 4.7 4.7 4.6 5.0 5.6 Mean 12.0 12.1 12.5 12.4 13.2 14.5 Density (vpm) Max 19.8 19.9 20.0 20.7 21.9 23.7 Min N/A -2.2% -2.3 -1.8% -0.5% -0.4% Mean N/A 0.85% 0.76% 0.94% 1.24% 1.78%
% Cha nge in HOV Lane Travel Time
Max N/A 5.3% 7.3% 4.7% 8.1% 8.0% Mean 1064 1065 1061 1077 1206 1225
Flow (vph) Max 1265 1264 1290 1289 1380 1515
Results
Performanc e Measure Baseline Scenario
1 Scenario
2 Scenario
3 Scenario
4 Scenario
5 Number of Sections with LOS A
25 23 24 25 19 13
Number of Sections with LOS B
15 17 14 13 20 23
Number of Sections with LOS C
1 1 3 3 2 5
Number of Sections with LOS D or Above
0 0 0 0 0 0
Number of Periods where Flow > 1800 vph
0 0 0 0 0 0
Results
• No significant degradation of HOV lane operations in study area
– Flows on SB I-5 in Santa Ana reached 1515 vph
• Results do not preclude degradation on other facilities in the state or country
Conclusions
• Policy may be implemented without widespread HOV lane degradation
• Hybrid sales strong
• “Take away” problem
• Virginia law set to expire on July 1, 2006
• Phase in toll lanes
• Better use of HOV lanes
• HOT lane
• Priority-based HOV operation
Policy Implications
Questions?