California`s managed lane design policy

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Transcript California`s managed lane design policy

Joe Rouse
California Department of Transportation
Division of Traffic Operations
Office of System Management Operations
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Background
◦ Need and purpose for Policy Directive
◦ Lessons Learned/Special Studies/Research Findings
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Changes To Technical/Procedural
Expectations and Requirements
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Access type, location, spacing & design
Operational & safety analyses
Adoption of 2009 federal MUTCD
Enforcement provisions
HOV Guidelines Update
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Need for the Policy Directive
◦ Traffic engineering research and "lessons learned" from our
southern California HOV network identified :
 A need for updated Intermediate Access design
 A need for more specific guidance on operational analysis
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Purpose of the Policy Directive
◦ Ensure that managed lanes will provide the performance that
customers will expect: RELIABLE travel time savings
◦ Clarify and expand the traffic operational and safety analyses
that are needed for managed lane facilities
◦ Address other issues, such as CHP policy changes and FHWA
policies
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Intermediate Access Locations on Limited
Access Managed Lanes
◦ Three types identified
 Weave Zone – Combined ingress/egress
 Weave Lane – Combined ingress/egress with a weaving lane
 Merge Lane – An ingress or an egress with a merging lane
◦ New Performance Thresholds
 Openings should operate at LOS “C” or “D”
 Placed where recurrent congestion isn’t occurring or is expected
 Stronger language than what is currently used in HOV
Guidelines
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Intermediate Access Locations on Limited
Access Managed Lanes (Cont’d)
◦ New Lengths
 800 feet per lane change between opening and adjacent ramp
(was 650 feet)
 Openings should be 2000 feet (was 1300 feet)
◦ Lighting
 Required for all access points
 Recommended for major weaving areas
2003 HOV Guidelines
Figure 4.2
Weave Zone
Weave Lane
Merge Lane
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Operational & Safety Analysis
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Required for all managed lane projects
Performed during environmental phase
Objective is to ensure facility meets operational thresholds
Operational Analysis contents
 Freeway mainline analysis
 Merge/diverge analysis of drop ramps/direct connectors
 Operational analysis of access points
 Iterative process – try till you find one that works
 Analytical method subject to approval of district operations
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Operational & Safety Analysis
◦ Safety Analysis
 Performed by Caltrans-District Traffic staff
 Ensures that projects will not result in new safety “hot
spots” or increase potential for severe or serious
collisions
 Will recommend enhancements to the managed lane
facility that are simple, practical to implement, and
effective
 Not intended to add other improvements to the scope of
work
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Signing – Based on 2009 MUTCD
◦ “HOV” used instead of “CARPOOL”
 Requires changes to many California signs, some new
signs, some eliminated
◦ FHWA wants signing guidelines in MUTCD
 Will not be in HOV Guidelines
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Striping – Based on 2009 MUTCD
◦ FHWA has requested compliance with MUTCD
◦ Striping changes required amendment to Vehicle Code
◦ FHWA wants striping guidelines in MUTCD
 Will not be in HOV Guidelines
Limited access striping – CURRENT
One set of yellow stripes
Limited access striping – PROPOSED
One set of white stripes
Limited access striping – CURRENT
Two sets of yellow stripes
Limited access striping – PROPOSED
Two sets of white stripes
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Enforcement
◦ CHP no longer using left shoulder
 Barrier separation or channelizers required for left
shoulder use
◦ Observation areas desirable
 Similar in design to enforcement areas
 Located downstream of toll readers
 Other locations as desired by CHP
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Changes to be made to current Guidelines
◦ Convert to English units
◦ Updates to intermediate access design
◦ More cross referencing to MUTCD and HDM
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Policy guidance document
◦ Update to DD-43 by end of 2012
◦ More detailed policy guidance by April 2014
 Will address issues such as increasing occupancy,
adding capacity, and transponder requirements
Comments or Questions?
Joe Rouse
[email protected]
(916) 654-6448