45
Decision Making: Putting Data to Work 2016 National Pavement Preservation Conference Nashville, Tennesee Scott Gibson P.E.
Decision Making:
Putting Data to Work
2016 National Pavement Preservation Conference
Nashville, Tennesee
Scott Gibson P.E.
About the RTC (Regional Transportation Commission)
RTC of Washoe County, NV MPO (long range mobility)
Transit (mode split and trip reduction)
Engineering and Construction (Provides
Opportunity)
Member Agencies:
• Reno
• Sparks
• Washoe County
Funding: Indexed Fuel Tax
Passed Twice by Voter Initiative CPI then PPI (Construction Inflation)
Indexes County Fuel Tax to Inflation
Also: Indexes State Fuel Tax and Keeps
that Increment,
Index Federal Gas Tax and Keeps that,
Indexes Federal Diesel Fuel Tax and Keeps that!
Local Regional Roads and RTP Roads
3,500 Lane Miles(70%)
1,500 Lane Miles(30%)
Local RegionalRoads:Residential,Minor Collectors
RTP Roads:Arterials, MajorCollectors,Industrial
8%
50%
42%
Residential
Arterials
Interstate
Vehicle
Regional and RTP Roads
Integrated Elements
Condition Survey Calibration PCI from Agency Pavement Management Systems (Can’t
be more than 3 years old!)
Uniform Regional Road Categories Arterial, Collector, Industrial
Regional Treatments Slurry seal, micro-surfacing, thin overlay, patching
Pavement Preservation Program
Rehabilitation / Reconstruction PCI 0-50
Rank by Traffic PCI 40-50 Rehabilitaion
PCI 0-40 Reconstruction
Preventive Maintenance PCI 56-100
Structural Distress less than 5%
Corrective Maintenance Everything Else (≈PCI 45-65)
Variety of Tools
Cost Effectiveness
Agency Driven
Pavement Preservation ProgramProgram Elements
Long Range Transportation Plan Future Transportation Needs
Future Budget for achieving network condition goals
Current Program of Projects Project Priorities for construction and maintenance
Continuous Improvement Doing it better, faster, and more cost effectively.
What Decisions do We Make?
Old Engineers
Pavement Management Systems PCI
Research UNR
Western Region SuperPave Center
Center for Advanced Transportation Education and Research (Cater)
National Studies
Public Outreach/Community Involvement Project Media
Corridor Studies
What Data Sources do We Use?
Type 3 Microsurface
PavementCondition
(Functionalor
Structural)
Time (Years)
Preventive Maintenance
Good
Poor
When should preventive
maintenance be applied?
Network Performance Life after Preventive Maintenance
10 Years
StreetSaverDashboard
National Research
Phase I: Slurry Seal Performance Life &
Extension in Pavement Service Life
University of Nevada Reno,
www.wrsc.unr.edu
14
0
20
40
60
80
100
0 2 4 6 8 10 12 14 16 18 20
PC
I
Age in YearsNew Construction Slurry Seal at year 3
0
100
0 20
PC
I
Slurry Seal at year 7
Extension in Pavement
Service Life 2 yrs
Performance Life 2
yrs
Performance Life 3
yrs
Phase I: SS Performance Life &
Extension in Pavement Service Life
University of Nevada Reno,
www.wrsc.unr.edu
15
In general, performance life ranged between 2 & 4
years.
Except when slurry seal was applied at year 0 and 1,
performance life ranged from 0 to 1 year.
Except few cases, the pavement service life was not
extended by application of the single slurry seal.
Phase I: Slurry Seal Effectiveness
0
10
20
30
40
50
60
70
80
90
100
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
PC
I
Age (years)
Overlay (Do
Nothing) Slurry
Seal
Relative Benefit = 100B / B0
BB0
Benefit Cost Ratio = B / C
University of Nevada Reno,
www.wrsc.unr.edu
16
Phase I: Effectiveness Analysis –
New Construction
0
100
200
300
0 1 3 5 7 9
Ben
efi
t (P
CI.
yrs
)
Year of Slurry Seal ApplicationNC-Arterial (A) NC-Collector (B)
0%
50%
0 1 3 5 7 9
Rela
tive B
en
efi
t
Year of Slurry Seal Application
NC-Arterial (A) NC-Collector (B)
University of Nevada Reno,
www.wrsc.unr.edu
17
-5
5
15
25
0 1 3 5 7 9
Ben
efi
t-C
ost
Rati
o
(x1000)
Year of Slurry Seal Application
NC-Arterial (A) NC-Collector (B)
Phase I: Effectiveness Analysis –
Overlay
0
50
100
150
200
250
0 1 3 5 7 9
Ben
efi
t (P
CI.
yrs
)
Year of Slurry Seal ApplicationOL-Arterial (A) OL-Collector (B)
0%
20%
40%
60%
80%
0 1 3 5 7 9
Rela
tive B
en
efi
t
Year of Slurry Seal ApplicationOL-Arterial (A) OL-Collector (B)
University of Nevada Reno,
www.wrsc.unr.edu
18
0
5
10
15
20
25
0 1 3 5 7 9
Ben
efi
t-C
ost
Rati
o
(x1000)
Year of Slurry Seal ApplicationOL-Arterial (A) OL-Collector (B)
Phase I: Conclusion
University of Nevada Reno,
www.wrsc.unr.edu
19
Application of SS immediately or one year after
construction of asphalt layer is not effective in terms of:
the benefit to the users and
the benefit-cost ratio for the agency.
Optimum time for application of a Single Slurry Seal:
Newly constructed pavements: 3 years after construction.
Pavements subjected to overlays: 3-5 years after
construction.
0
20
40
60
80
100
0 2 4 6 8 10 12 14 16 18 20
Pre
sen
t C
on
dit
ion
In
dex (
PC
I)
Age in Years
Phase II: Newly Constructed Pavements:
1st SS at year 3, 2nd SS at year 7
University of Nevada Reno,
www.wrsc.unr.edu
20
1st slurry seal
2nd slurry seal
Predicted
Do-Nothing
performance curve
(Using performance
models developed
in Phase I)
Predicted
SS at year 3
performance curve
(Using performance
models developed
in Phase I
4.0 yrs 3 yrs
3.5 yrs
University of Nevada Reno,
www.wrsc.unr.edu
21
0.5
0.7
2.7
2.9
3.3
0.5
0.4
4.1
4.3
3.8
2.2
1.5
1.7
1.8
3.3
2.4
2.3
3.2
3.3
1.7
3
3.3
2.5
1.7
1.7
1.1
0.7
0.6
3.3
3.5
2.7
1.2
0.4
0.9
0.5
3.6
3.2
2.2
0 1 2 3 4 5
OL-0-7
OL-0-9
OL-1-7
OL-1-9
OL-3-7
OL-3-9
OL-5-9
NC-0-7
NC-0-9
NC-1-7
NC-1-9
NC-3-7
NC-3-9
NC-5-9
Years
Performance life of 1st SS
Performance life of 2nd SS
Extension in pavement service life
Phase II: Slurry Seal Effectiveness
Relative Benefit = 100B / B0 Benefit-Cost Ratio = B / C
University of Nevada Reno,
www.wrsc.unr.edu
22
0
20
40
60
80
100
0 2 4 6 8 10 12 14 16 18 20
Pavem
en
t C
on
dit
ion
Ind
ex (
PC
I)
Age in Years
NC-C-3-9NC-C-3-9
BB0
Phase II:
University of Nevada Reno,
www.wrsc.unr.edu
23
Effectiveness
www.wrsc.unr.edu ; www.arc.unr.eduSlide No. 24
UNR-RTC Pavement Technology Research
www.wrsc.unr.edu ; www.arc.unr.eduSlide No. 25
Current Projects: Overall ProgressEffectiveness of Cape Seal Pavement Preservation
• Collected pavement information and performance data.
• Working on data processing and analysis.
DST-MS
DST-SS
www.wrsc.unr.edu ; www.arc.unr.eduSlide No. 26
Chism St. -15%RAP+WMA (6” PG64-22)
Excellent100
85
70
55
40
PCI Rating
Failed
Very Good
Good
Fair
Poor
Very Poor25
010
0
10
20
30
40
50
60
70
80
90
100
2008
2009
2010
2011
2012
2013
2014
PC
I
Date
Dat
e o
f
Co
nst
ruct
io
n -
6/11
/200
9
Microsurfacing
www.wrsc.unr.edu ; www.arc.unr.eduSlide No. 27
Overview
125
0.75
19
0.5
12.5
0.37
59.
5
No.
44.
75
No.
82.
36N
o. 1
02
No.
16
1.18
No.
30
0.6
No.
40
0.42
5N
o. 5
00.
3N
o. 1
000.
15N
o. 2
000.
075
0
10
20
30
40
50
60
70
80
90
100
Per
cen
t P
assi
ng
Sieve Size (inch)
Max Density Line
Type 2
Type 2C
Type 2-Revised
Sieve Size (mm)
Network Performance Life after Preventive Maintenance
10 Years
Complete Street Concept
“My favorite subject:
watching asphalt
congeal.”
Complete Streets /Road Diets
Before: incomplete urban street
4-lane undivided
No center turn lane
No bike facilities
Numerous driveways
Pedestrian unfriendly
Wide lanes
No designated parking
Complete Streets /Road Diets
After: More complete urban street
3-lane divided
Center turn lane
Bike facilities
Pedestrian Friendlier
Narrow lanes
More Parking
Free!
Neighborhood Building
Safer Streets
Location Before After %
Reduction
Wells Ave -31%
California/Ma
yberry
33.4 19.4 -42%
Arlington 18.6 10.0 -46%
Mill Street 7.7 4.4 -43%
Sources: UNR Center for Advanced Transportation Education and Research and Nevada Department of Transportation
Recent Road Conversions Reduce – Annualized Crash Rates
Complete Street/Road Conversions
Significant safety benefits:
• Lower speeds,
• Reduced conflict points and crashes,
• Better sight distance,
• Refuge for pedestrians,
• Space for bicycles (and others)
6 conflict points Vs. 2
conflict points
Making Adjustments/Costs
• Striping design
• Lane reconfiguration
• Signal Head placement
• Signal timing
• Loop detection
• Continued evaluation
• Added maintenance costs
• Honey Dos
Other Opportunities –
TCSP Grant – Sutro Complete Street
Other Opportunities –
TCSP Grant – Sutro Complete Street
Good Roads are Cheaper!
33%
20% 21%26%
2%5%
21%
72%
0.3%1.2%
10.1%
88.4%
Very Poor Poor Fair Good
Bay Area
All RegionalRoads
RTP
System Equity Provides for Major Opportunity
Chip Seals
And Roll.
UC Davis Surface Effects Study
UC Davis Surface Effects Study
Bike Mounted
Accelerometer
s and GPS
Correlated to
Laser Surface
texture
Measurements
UC Davis Surface Effects Study
Also Correlated
to Inertial
Profiler…
And to sand
patch
Measurements
Urban Surface Study
Parting Thoughts on Good Data
and Good Decisions
• There are many data sources available.
• Not only can good data help you make good decisions about your program but it can help decision makers make good decisions about supporting your program.
• Data can help make your pavement program part of a bigger conversation: safety, Complete Streets, and stronger communities and neighborhoods.
