TRANSPORTATION SOLUTIONS: GETTING THE MOST BANG FOR YOUR BUCK!
GPA Fall Conference 2013Garth Lynch, PE, AICP
HNTB CorporationOctober 10, 2013
Agenda• Overview of study• Identification of bottlenecks• Potential operational strategies• Project prioritization• Next steps
Metro Atlanta OPS
OVERVIEW OF STUDY
Study Area• All limited access
facilities in metro Atlanta
• Emphasis on improving the Interstate mainline
Objectives• Identify bottleneck
areas • Identify and evaluate
potential low-cost improvements
• Quick implementation – 6 months to 5 years
• Document a prioritized list of operational projects
Metro Atlanta OPS
IDENTIFICATION OF BOTTLENECKS
Identification of Bottleneck LocationsData Inputs User Inputs
Speeds & counts Bus drivers
Aerial congestion survey Unit operators
GPS speeds & duration of congestion
GDOT TMC staff
Stakeholders
HERO
Causes of Bottlenecks• High volumes• Weaving• Lane drops/additions• Last minute decision making• Lack of storage on ramps and/or high turn volumes• Tight turning radii and/or steep grade on ramps• Frontage road access• Limited access facility terminates at signalized
intersection• Suspected drainage issues
Identified Bottleneck Locations
Metro Atlanta OPS
POTENTIAL STRATEGIES
Potential Strategies• Added Corridor
Capacity (MLIP)• Improved Design
Geometrics• Intelligent
Transportation Systems• Freight• Demand Management
& Policy Considerations
System-wide Strategies for Consideration1) Expand ITS2) Advanced queue warning signs 3) Variable speed limits 4) Dynamically shoulder usage5) Upgrade CCTV cameras / traffic flow monitoring6) Increase crash investigation sites7) Modify ramp meters to permit 2 cars per green8) Expand quick response incident clearance9) Expand HERO units10) Modify truck lane restrictions
Types of Location-Specific Strategies for Consideration
1) Variable / dynamic ramp closures (closed to all vehicles v. closed to unauthorized vehicles)
2) Auxiliary lanes (new or using shoulder)3) Collector / distributor roads4) Modifications to frontage road access5) Channelization6) Re-striping7) Interchange reconfigurations (Diverging Diamond
Interchanges, etc.)
Types of Location-Specific Strategies for Consideration
8) Turning prohibitions
9) Additional ramp meters
10) Modify existing ramp meter operations
11) Modify ramp geometrics, with a focus to better accommodate trucks
12) Automated truck rollover warning systems
13) Ramp meter bypass lanes for transit and vanpools
Potential Strategies
Potential Solutions:
71 operational strategies(13 types)
at 45 locations
Active Traffic Management (ATM)
Source: FHWA Best Practices for Road Weather Management: Minnesota DOT I-35W Smart Lanes: Active Traffic Management. Located at: http://ops.fhwa.dot.gov/publications/fhwahop12046/rwm17_minnesota1.htm
Lane Control Signals During an Incident
Source: Washington State Department of Transportation Smarter Highways: http://www.wsdot.wa.gov/smarterhighways/
ATM Sign Example
Variable Speed Limit Sign Example
Active Traffic Management (ATM)
Ramp Meter Bypass Lane for Transit
Innovative InterchangeReconfiguration Options
Diverging Diamond Interchange (DDI) Partial DDI
Modified DisplacedLeft Turn
I-75 / I-85 (Downtown Connector)at Williams St
N
Ivan Allen Jr. Blvd
Will
iam
s St.
W Peachtree Pl
FromTo
Will
iam
s St.
Ivan Allen Jr. Blvd
W Peachtree Pl
Option 1: Left turns would shift to W Peachtree Pl
Option 1: Prohibit left turn at Ivan Allen Jr Blvd
Option 2: Provide SB right turn arrow & re-
stripe taper
Source: Google
Option 3: Add 2nd right turn lane from Ivan Allen Jr Blvd to Williams St
Option 4: Allow 2nd right turn/thru lane
Strategies Being Considered by Cost Range
• OPS projects being input into project prioritization process– 71 projects totaling
approximately $159 M
39 projects20 projects
11 projects
1 project
Number of Projects Being Considered by Cost Range<$1m $1m-$5m $5-$10m >$10m
Metro Atlanta OPS
PROJECT PRIORITIZATION
Project Prioritization Structure Goals
National & State Goals
Local Goals
Project Prioritization Structure
Preliminary Project Prioritization StructureNo. Themes Performance Measures
1 Transportation mobility
Vehicle throughput
Changes in travel speeds or travel time savings
Reduction of vehicle delay
Facilitation of transit options
2 Financial feasibilityCost
Benefit/cost ratio
3 SafetyAnticipated reduction of crashes
Anticipated reduction of incident response time
4 Connectivity and economic growth
Facilitation of current major freight movement
Connectivity to current major employment centers
5 System preservation and environmental sustainability
System preservation
Level of environmental impacts
6 Project support and readinessProject readiness
General constructability and schedule
Metro Atlanta OPS
NEXT STEPS
Next Steps
SR 400 at Holcomb Bridge Rd (SR 140)
Holcomb Bridge Rd.
SB O
ff-Ramp
Dogwood Rd.
Added Thru Lane
Added Right Turn Lane
N
Source: Google
Thru Lane
Option 1: Add right turn lane and one thru lane
I-85 North at Hamilton Mill Rd
N
Source: GA GIS Clearinghouse
Braselton Hwy.Braselton Hwy.
Hamilton M
ill Rd.
Existing Proposed
Step 1: Create indirect left turn intersection and eliminate SB left turn
Step 2: Eliminate one SB lane and add NB lane
Step 3: Create free flow right turn lane
SR 124SR 124
Source: Google
Hamilton M
ill Rd.
I-285 S at I-85 S Interchange
N
Source: Google
US 29
Option 1a: Widen and restripe existing merge from I-85 NB to
create two-lane on-ramp
Option 1b: Restripe Old National Hwy. On-ramp
Old National C/D
I-85 NB
I-285 W / I-20 W
Source: GA GIS Clearinghouse
N
Option 1: Add 2 mainline lanes on I-20 WB from I-285 SB/NB
Option 2: Create new C/D road and continue ramps onto new bridge over I-285
Option 1: Drop mainline lane on I-20 WB to I-285 SB
