California`s managed lane design policy
Download
Report
Transcript California`s managed lane design policy
Joe Rouse
California Department of Transportation
Division of Traffic Operations
Office of System Management Operations
Background
◦ Need and purpose for Policy Directive
◦ Lessons Learned/Special Studies/Research Findings
Changes To Technical/Procedural
Expectations and Requirements
◦
◦
◦
◦
Access type, location, spacing & design
Operational & safety analyses
Adoption of 2009 federal MUTCD
Enforcement provisions
HOV Guidelines Update
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
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
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
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
Operational & Safety Analysis
◦
◦
◦
◦
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
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
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
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
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
Changes to be made to current Guidelines
◦ Convert to English units
◦ Updates to intermediate access design
◦ More cross referencing to MUTCD and HDM
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