HCM 2010
HCM 2010
HCM 2010
5th Edition
Updates
Chapter 26 (Adopted): Interchange Ramp Terminals Chapter X (Evaluation Copy): Local Urban Streets NCHRP Report XXX: Analysis of Freeway Weaving Sections
Roundabouts
Roundabouts Procedure
Can be calibrated to locally measured critical headway and follow follow-up headway Sensitive to turning movement assignment to individual lanes Sensitive to lane utilization User has ability to assign traffic by lane to match existing or projected conditions RightRight -turn bypass lanes
Type 1: Yielding Type 2: Non Non-yielding (acceleration or add lane)
PCE adjustment for heavy vehicles PHF adjustment for peak 1515-minute flows LOS definitions
Roundabouts
Weaving
LS LB LL
WEAVING - No More: Configuration Types (A,B, and C) Unconstrained vs. Constrained Operation New Variables Describing Configuration: LCMIN = minimum number of lane changes for all weaving vehicles to successfully complete their desired weaving maneuvers. NWL = number of lanes from which a weaving maneuver can be made with no more than one lane change. Two-Sided Weaving Segments Considered as a Special Case
v /N S
Density (pc/mi/ln)
Weaving Sections on CC-D Roadways or Multilane Highways 0 12 > 12 24 > 24 32 > 32 36 > 36
A B C D E F
Urban Streets
Automobile Methodology
Analysis Unit Segment Includes all movements at signals Can include movements at access points Supports facility analysis Active Access Point Subject Intersection Upstream Intersection
- Subject segment
Methodology
Actuated Phase Duration Prediction Controller operation inputs Simultaneous gap gap-out Dallas phasing Controller phase inputs Passage time Minimum green Recall Dual entry HCM Chapter 16 -Appendix B
Methodology
Coordinated-Actuated Operation CoordinatedController inputs Force mode Splits used to estimate force off & yield F.O. F.O. Y.P. points Offset & offset reference point
Offset F.O. F.O. Y.P.
Methodology
Arrival Flow Profile Prediction Computes adjusted volume Balance flows between junctions Check and honor capacity constraints to entry flows Computes OO-D matrix Distribution of each entry mvmt. to all four exit movements Based on turn turn-mvmt. estimation method in Chapter 10
Upstream Intersection Subject Intersection
Methodology
Spillback Prediction Sustained queue backs up for length of segment Model prediction Identify time when spillback occurs Uses Indicates green needs to be better allocated Indicates simulation should be considered
Performance Measures
Average travel speed Control delay Stop rate
Types of Interchanges
Diamond with continuous frontage roads
Parclo A, 2 Quadrants
Parclo A, 4 Quadrants
Parclo B, 2 Quadrants
Parclo B, 4 Quadrants
Demand Starvation
Next Steps
HCS+ Now Incorporates Interchanges NCHRP 3 3-60 Extension - Collecting Additional Field Data - Incorporate Nearby Intersections - Include 33-65 Roundabouts HCM 2010 to incorporate New Interchange Method
HCS+Interchanges
Software Released HCS+ 5.3 McTrans