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Planning and Preliminary Engineering Guide For Using the Highway Capacity Manual. NCHRP 7-22 Workshop. Agenda. The Project (9:00 AM) Overview of the Guide (9:30 AM) Case Studies Long Range Regional Plan Update (10:30 AM) Freeway Master Plan (11:30 AM)
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Planning and Preliminary Engineering Guide For Using the Highway Capacity Manual NCHRP 7-22 Workshop
Agenda • The Project (9:00 AM) • Overview of the Guide (9:30 AM) • Case Studies • Long Range Regional Plan Update (10:30 AM) • Freeway Master Plan (11:30 AM) • Urban Street BRT Project Planning (2:00 PM) • System Performance Monitoring (2:45 PM) • Wrap Up (3:15 PM)
NCHRP 7-22 • To develop a guide to help planners take advantage of the HCM to improve their results. • Status • Stakeholder workshops held to identify planning needs and how the HCM might help. • Initial rough draft guide for stakeholder review (October) • Revised draft guide for panel review in December. • Final guide submitted for publication June 2015
The People • The Research Team • Kittelson & Associates - Rick Dowling, Paul Ryus • North Carolina State University - Bastian Schroeder • University of Idaho - Michael Kyte • Stantec – Tom Creasey • The Panel
2. Overview of Guide 09:30
Contents • Part I - How To Use the Guide • Long and Short Range Areawide Planning • Project Traffic and Environmental Studies • Highway Performance Monitoring • Part 2 – Procedures • Part 3 – Case Studies • Long Range Regional Transportation Plan Analysis • Freeway Future Conditions Analysis • Analysis of BRT Project on Urban Street • Roadway System Monitoring
Part 2 - Procedures • Default Values • Generalized Service Volume Tables • Working with Traffic Demand Data • Intersection Traffic Control • Guidance for Freeways • Guidance for Multilane Highways • Guidance for Two-Lane Highways • Guidance for Urban Streets • Guidance for Signalized Intersections • Guidance for Stop-Controlled Intersections • Guidance for Roundabouts • Guidance for Interchange Ramp Terminals • Guidance for Off-Street Pathways • Guidance for Corridors • Guidance for Areas and Systems Input Data Facilities Intersections Other
Part 2 – Section E:Freeway Procedures • E1. Overview • E2. Computational Tools • E3. Data Needs • E4. Estimating Inputs • Free flow Speed • Capacity • E5. Performance Measures • Speed • Level of Service • Queues • Reliability
Part 2 – Section H:Urban Street Procedures • H1. Overview • H2. Computational Tools • H3. Data Needs • H4. Segment Performance • H5. Intersection Perform. • H6. Facility Performance
Part 2 Section I –Signalized Intersections • I1. Overview • I2. Computational Tools • I3. Data Needs & Limits • I4. Performance Estimation • Screening – Critical Lane Vol. • v/c ratio • Delay • LOS • Queue • Reliability (sensitivity analysis) • Bike/Ped LOS – see Section M
Part 2 Section O –Areawide Analyses • O1. Overview • O2. Computational Tools • O3. Data Needs • O4. Estimate Demand Model Inputs • Free-Flow Speed • Capacity • O5. Performance Measures • Auto – V/C, Speed, VHT, Delay, LOS, Density, Queue, Reliability.
Comments So Far? • Outline and Contents of Guide (Part 1, 2, 3) • What do you like so far? • What do you dislike? • What is missing?
3. Case studies 10:30
Case 1 - LRTP • Fresno COG 2040 Regional Transportation Plan • - 6,000 square miles • - 1 million population
Objectives • Conduct transportation performance and investment alternatives analysis required to update 2040 LRTP • Auto, truck, bus, bicycle, and pedestrian analyses to be performed. • Travel Demand Forecasting Model to be Used
Example Problems • Example Problems that Develop Demand Model Inputs • Example I.1 – Estimation of Free-Flow Speeds and Capacities • Example I.2 – HCM Based Volume-Delay Functions • Example Problems Post Processing Demand Model Outputs • Example I.3 – Estimating Speeds for Air Quality & Noise Analysis • Example I.4 – Screening for Auto V/C and LOS Hot Spots • Example I.5 – Predicting Queues & Delay • Example I.6 – Interpretation of Results • Example I.7 – Prediction of Reliability • Example I.8 – Transit, bicycle, and pedestrian LOS screening • Example I.9 – Truck LOS screening
Example I.1 – estimating Free-flow Speeds & Capacities • Objective • To develop lookup table of free-flow speeds and capacities for coding the highway network • Approach • Step 1: Identify facility categorization scheme • Step 2: Determine free-flow speeds • Step 3: Determine capacities
For Free-Flow Speeds • Consult Appropriate HCM Chapter for Procedure, or • Use Posted Speed Limit + 5 mph
For Free-Flow Speeds • Consult Appropriate HCM Chapter for Procedure, or • Use Posted Speed Limit + 5 mph
Use “No-Fault” Capacity Table from part 2 - Section o Arterial/Collector assume 1900 ideal sat flow rate
Pick 80% HCM PC Capacity Arterial/Collector assume 1900 ideal sat flow rate
Comments? • Example I.1 – Creation of free-flow speed and capacity look-up tables
Example #I.2 – HCM Based Volume-delay Functions • Objective • To select an HCM based volume-delay function for demand model • Approach • Step 1: Select volume-delay function type • BPR and Akcelik • Step 2: Set parameters • Match Speed at Capacity • Compute Akcelik parameter • Compute BPR parameter • Step 3: Select preferred volume-delay function
Akcelik Where: T0 = Free-flow travel time X = volume/capacity ratio J = calibration parameter L = length of the link
BPR Where: T0 = Free-flow travel time X = volume/capacity ratio A = speed at capacity calibration parameter B = rate of travel time increase calibration parameter
Smooth vs Rough Pipe BPR Akcelik Everybody waits their turn here. Everybody goes slow entire length T Free-Flowing here
Splitting Smooth & Rough PipeS BPR Akcelik 0.5 T or T T or 2T T Problem for DTA, No Problem for SUE Models No Problem for DTA, Problem for SUE Models
Comparing Speeds Speed at Capacity
Calibrating to Speed at Capacity Akcelik BPR
All Get Same Speed at Capacity Speed at Capacity