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CTP Modeling Clayton & Newton Counties Eric Lusher ARC Model User’s Group February 29, 2008
CTP ModelingClayton & Newton Counties
Eric Lusher
ARC Model User’s Group
February 29, 2008
CTP Process
Envision6
Regional
Transportation
Plan
CTP Process
Regional
Development Plan
Sub-Area Validation
TAZ splitting
Newton County
Southwestern suburban communities
Central Covington Area
Northwestern part of County
Clayton County
Forest Park Area
Central Jonesboro
I-675 Corridor
Southlake Mall
New Roadway coverage
Functional Class revisions
Sub-Area Validation
Newton County
31 TAZs 51 TAZs
Sub-Area Validation
Clayton County
62 TAZs 107 TAZs
Sub-Area Validation
Land Use/Socioeconomic Data Correlation
Land Use Name Assignment
AF Agricultural/Farming 50% Population / 50% Employment
COM Commercial Employment
IND Industrial Employment
INS Public Institution Employment
MHDR High Density Residential Population
MHP Mobile Home Park Population
MX Mixed Use 50% Population / 50% Employment
PUB Public Employment
RES Residential Population
RR Railroad Employment
TCU TCU Employment
UCC Under Construction Commercial Employment
UCI Under Construction Industrial Employment
UCR Under Construction Residential Population
VAC Vacant 50% Population / 50% Employment
Sub-Area Validation
Sub-Area Validation
Newton County
Sub-Area Validation
Clayton County
Needs Assessment
Needs Assessment conducted by examining changes between several years and scenarios
2005 (Baseline)
2010
2020 E+C
2030 E+C
2030 Envision 6
2030 E+C High Growth Scenario (Newton County Only)
Needs assessment performance measures:
LOS
Model based V/C ratios
Post-model Analysis
Travel Time
Needs Assessment
Model based V/C ratios
Post-Model LOS
Applies changes in volume from year to year to existing AADT counts
AADTd = AADTf + (AADTbc – AADTbm)
where
AADTd =difference adjusted future year AADT forecast
AADTf =future year model AADT
AADTbc =base year (existing) AADT estimated from traffic counts
AADTbm =base year model AADT
Compares forecasted volume to generalized service capacities derived from Highway Capacity Manual (ARTPLAN, LOSPLAN, HIGHPLAN)
Increasing sophistication by incorporating roadway characteristics into service volume where data is available
High truck percentages
Peak-to-daily ratios
Directional factors
Traffic Signal spacing
Performance Measures
Needs Assessment
Performance Measures
Needs Assessment
Peak Period Travel Time Analysis
Performance Measures
Travel Time Change From 2005
-10.00 0.00 10.00 20.00 30.00 40.00 50.00
I-20
SR 81 & SR 142
SR 81
SR 212
US 278
SR 81
Browns Bridge Road
Cromwell Road
SR 36
Travel Time
Envision 6 2030 E+ C 2030 E+ C High Growth Scenario
Needs Assessment
Misc. Model Applications
Intra-County Transit Propensity
Strategy Development
Both CTP projects currently in strategy development phase
Clayton County
Envision 6 Projects appear to address most major mobility issues
Major Challenges (through traffic):
SR 85 corridor (congested w/ and w/o planned projects)
I-75 / I-85 / I-285 / I-675
Newton County
Envision6 Projects address critical needs
Major Challenges:
High Growth Scenario
Congestion in the western suburbs
Interstate 20 access
Strategy Development
2030 Envision6
Strategy Development
2030 E+C High Growth
NEXT STEPS
Develop project alternatives for each County
Incorporate citizen and County staff local knowledge/concerns
Test different combinations of projects
LOS
Preliminary project prioritization performance
Phasing/Prioritization
Address current needs
Address future needs
Prepare phasing to correlate with future development
Prepare Final Recommendations
?’s
?’s
Questions?
Eric Lusher
Senior Transportation Planner
400 Northpark Town Center
1000 Abernathy Road, NE
Suite 900
Atlanta, GA 30328
Tel: 678.808.8823
Eric_Lusher at urscorp.com
