Title: Modeling HOV lane choice behavior for microscopic simulation models and its application to evaluation of HOV lane operation strategies
1Modeling HOV lane choice behavior for microscopic
simulation models and its application to
evaluation of HOV lane operation strategies
- Jun-Seok Oh
- Western Michigan University
- Lianyu Chu
- University of California, Irvine
2Investigation of HOV Modeling Capability in
Microscopic simulation Models
- Jun-Seok Oh
- Western Michigan University
- Lianyu Chu
- University of California, Irvine
3Content
- Motivation and Objectives
- Classification and Operation of HOV System
- Analytical Model for HOV Lane Traffic Estimation
- HOV Modeling in Microsimulation Models
- Experiment and Performance Comparison
- New Modeling Approach
- Concluding Remarks
4Motivation
- FHWA encourages the installation of HOV lanes as
an important part of an area-wide approach - There are still questions on
- the effectiveness of HOV systems
- their impacts on air quality
- The benefits of HOV systems have not been well
quantified - Microsimulation might be a good way, but still
involves some limitations
5Objectives
- Compare HOV modeling capability and performance
in - Paramics
- AIMSUN
- Identify limitations and investigate methods to
enhance HOV behavior modeling in microsimulation - Develop an improved HOV simulation analysis tool
using API capability
6Classification of HOV System
Infrastructure Mainline HOV lane Freeway-to-freeway direct connectors Direct local access ramps Freeway ramp meter bypass lanes Toll plaza bypass lanes
Designed Access Open system Closed system (Limits access with barrier)
Use Restriction 2 people minimum occupancy 3 people minimum occupancy Buses Vehicles paying toll (High Occupancy Toll)
Operational Period Full time operation Part time operation
7HOV Operations
8Analytical Model for HOV Lane Traffic Estimation
- User Equilibrium between HOV/GP
- HOV lane is faster than GP lanes
- tHL tGL
- fHOV(VHOV - VHG) fGP(VSOV VHG)
- If fHOV(VHOV) fGP(VSOV), VHG 0
- If fHOV(VHOV) gt fGP(VSOV), VHG gt 0
- VHG can be found by solving
- fHOV(VHOV - VHG) fGP(VSOV VHG)
9HOV Modeling in Microsimulation Models
- Vehicle Types
- SOV HOV
- Defining HOV Lane (Open HOV System)
- Allow HOV only on HOV lane
- Lane barrier (Closed HOV System)
- Closed HOV available in AIMSUN
- Closed HOV via plug-in in Paramics
10HOV Behavior Modeling
- Optional
- By allowing HOV only on HOV lane
- May underestimate HOV on HOV lane
- Compulsory
- By forcing all HOV to use HOV lane
- 100 HOV on HOV lane ? Unrealistic
- Separate links for HOV lane
- Route choice with dynamic feedback
- Not applicable to Open HOV
- Paramics provides HOV plug-in for more HOVs on
HOV lanes
11Experiment Scenarios
- Scenario 1 Closed HOV
- Using given capability
- Scenario 2 Separate Links for Closed HOV
- Treating closed HOV lanes as separated links
- Scenario 3 Open HOV
- No barrier between HOVL GPL
- Assumption HOV demand - 15 of total traffic
- MOEs
- Traffic volume split between HOVL GPL
- HOV demand split b/w HOVL GPL
- HOV demand split w.r.t speed of GPL
12Study Network I-405, Irvine, California
13Study Network I-405, Irvine, California
HOV open
HOV closed
HOV closed
HOV open
- Northbound I-405
- 6 km freeway stretch
14Scenario 1 Closed HOV
- Paramics Plug-in provided by vendor
- add additional layers of detail to the HOV
modeling - influence lane changing behavior and lane
discipline - model both open/closed HOV lanes
- AIMSUN Default function
- Restrict lane-changing with solid-line
15S1 Volume Comparison
- GP lane volume
- HOV lane traffic is underestimated
- Paramics HOV lane traffic constant during
simulation period
16S1 HOV traffic
- of HOV lane traffic
- of HOVs on HOVL
17S1 HOVs on HOVL w.r.t GPL Speed
- Paramics
- Not sensitive to the traffic condition on GPL
- AIMSUN
- Slower speed on GPL leads to more HOVs on HOVL
18Scenario 2 Separate links for closed HOV lanes
- Separate links for closed HOV lanes
- Use route choice model in HOV lane choice
- Dynamic link costs update
- HOVs are treated as guided drivers
- change route (lane) while driving
19S2 Volume Comparison
- of HOV lane traffic
- Close to observed HOVL volume
- of HOVs on HOVL
- 70 80 during congested period
20S2 HOVs on HOVL w.r.t GPL Speed
21Scenario 3 Open HOV Lane
- HOV can access anywhere
- HOV lanes are restricted only for HOVs
- Rely only on lane-changing restriction model
Dotted-line all open area
22S3 Volume Comparison
- of HOV lane traffic
- Underestimates HOVL volume
- of HOVs on HOVL
- Low HOLV utilization
23S3 HOVs on HOVL w.r.t GPL Speed
24Findings
- Closed HOV Lanes
- Underestimates HOVL traffic
- Paramics 65, AIMSUN 85 of observed
- Paramics Plug-in need improvement
- Better when incorporating route choice behavior
with dynamic cost update - Performance varies by route choice model
- Open HOV Lanes
- Current HOV modeling NOT satisfactory
- Paramics 60, AIMSUN 78 of observed
- Underestimates due to the lack of capability to
measure lane-by-lane traffic condition
25Other Scenarios
- Compulsory HOV Lane
- AIMSUN has an option for compulsory HOV
- Almost 100 HOVs use HOVL
- Not realistic for HOV lane analysis
- Useful tool for exclusive bus-lane
- Paramics
- Can implement by defining HOV only lane and SOV
only lane - But need to define area where both types can use
for exiting and entering - No HOV Lane
26Overall Travel Time Comparison
- Limited analyses
- Compulsory and No HOV lane case outperformed
- Elasticity of HOV demand NOT considered
27New HOV Modeling Approach
- Using API (Applications Programming Interface)
capability - Consider HOV drivers visual perception on
traffic condition - Visual perception-based instant HOV lane choice
model
28Concluding Remark
- Microsimulation needs to be enhanced for HOV
analysis - Closed HOV can be analyzed by incorporating route
choice model with separate HOV links - Open HOV analysis needs enhanced model
- Need to develop improved HOV behavior model
considering drivers visual perception on traffic
condition - Need to calibrate model using real-world data
- HOV demand and elasticity survey
- Microsimulation has potential for HOV evaluation,
but only with enhanced behavior model
29Thank you!