Presentation delivered at the CalAPA Spring Asphalt Pavement Conference April 9-10, 2014 in Ontario. Topic: New asphalt pavement smoothness specificaitons and measurement technology is discussed in depth.

2. Profilograph
Inertial Profiler
International Roughness Index (IRI/MRI)
Certification
Specifications
Submittals
Acceptance Criteria
Corrective Measures
Analysis Tool - ProVAL

3. Comfortable ride
Smoother roads:
last longer,
stay smoother longer,
safer,
saves money

4. Until recently, pavement smoothness was
measured using a California profilograph
and straightedge
The first profilograph was invented by
Francis Hveem and constructed in 1940 by
the Materials and Research Division of the
California Division of Highways.

6. Profile Index
0.2 inch blanking band
0.0 inch (Zero) blanking band
Must Grinds
0.3 inches in 25 feet

7. Because its front and rear wheels are in contact with the pavement surface, the
profilograph cannot accurately measure the pavement profile.

8. Actual Profile
Profilograph Trace
Phantom
Bumps
Dip
Dip

10. Front Mount Rear Mount
Side Mount

11. Human Response to Vibration
Vehicle Response to the Road
Road Roughness

12. Accelerometer
Reference elevation
Laser Height Sensor
Height relative to reference
Distance Measuring Instrument
Longitudinal distance

13. Accelerometers are used in a wide variety of
equipment and personal electronics including
seismology equipment, car alarm systems, and
crash detection/air bag deployment sensors.
In profilers, they measure the movement of the
vehicle body

14. The laser height sensors measure the distance from
the reference plane to the pavement surface. They
operate around 16KHz. At 60 mph they can take about
15 readings per inch of vehicle travel.

18. The site is located in the median of Interstate
80 at the Sacramento Regional Transit Light
Rail station (Watt/I-80) parking lot.
Two test sections (asphalt and concrete)
University of California Pavement Research
Center with the assistance of the Pavement
Program and METS will administer calibration
program
Calibration tests will be conducted 2 to 4 times
per year (March, May and July for 2014)
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19. 19

20. 20

21. Block Test
AASHTO R57-10, Section 5.3.2.3.1
This test will be conducted on a relatively flat and level area
It’s purpose is to check the height measurements from the
height sensor(s) of the test vehicle using blocks of known
heights (i.e. 0.5 inch, 1.0 inch, 2.0 inch).
Bounce Test
AASHTO R57-10, Section 5.3.2.3.2
It’s purpose is to ensures that the data from the height
sensor and accelerometer are legitimate and being properly
combined to compute the longitudinal elevation profile
Distance Measurement Index Test
AASHTO R56-10, Section 8.4
Tests accuracy of profilers distance measurement
instrument (DMI)
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22. Equipment Precision (Repeatability)
AASHTO R56-10, Section 8.3.1.2
Compare ten Inertial Profiler runs over same test
section against each other
Calculate repeatability agreement score
Score of 0.92 or greater is required
Equipment Accuracy (Reproducibility)
AASHTO R56-10, Section 8.3.1.4
Compare several inertial profiler runs over same test
section against a reference profiler
Calculate accuracy agreement score
Score of 0.90 or greater is required
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23. Failed tests (Equipment or Operator)
May re-test the following day (if site available)
Only one re-test per operator/equipment allowed
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24. International Roughness Index (IRI)
Computer Algorithm
Areas of Localized Roughness (aka “must grinds”)
Isolated areas of roughness

25. The International Roughness Index (IRI) is a
scale for roughness based on the simulated
response of a generic motor vehicle to the
roughness in a single wheel path of the
road surface.
IRI is used to define a characteristic of the
longitudinal profile of a traveled wheel
track.

28. Where B = 250 mm (9.8 in) for IRI
(represents tire contact with ground)

30. 0.1 mile 0.1 mile
ETW
RWP = Right Wheel Path
LWP = Left Wheel Path
ETW
Direction of Travel
RWP
LWP
IRI = 58 in/mi
IRI = 64 in/mi
IRI = 60 in/mi
IRI = 62 in/mi
Direction of Travel
MRI = 60 in/mi MRI = 62 in/mi

31. HMAAcceptance Values
MRI for each 0.1 mile section of a lane

32. AreasofLocalized Roughness
“Must Grinds” are now defined as “Areas of
Localized Roughness”
Areas of localized roughness uses a continuous IRI
for each wheel path with a 25 ft interval
Areas of localized roughness that exceed 120(160)
in/mile must be corrected regardless of the IRI
values of a 0.1 mile section
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33. AreasofLocalized Roughness
0
50
100
150
200
250
300
350
0 25 50 75 100 125 150 175 200 225
Distance (feet)
IRI(in/mi)
25-foot
sliding
window
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34. AreasofLocalized Roughness
“Must Grinds” will now be called “Areas of
Localized Roughness”
Areas of localized roughness use a continuous IRI
for each wheel path with a 25 ft interval
Areas of localized roughness that exceed 120
in/mile must be corrected regardless of the IRI
values of a 0.1 mile section

35. Certification
Inertial Profiler must be certified within the last
12 months
Profiler Operator must be certified within the
last 12 months
Contractors must obtain certification from the
California Certification Site (no longer Texas
Transportation Institute)

36. Submittals
Within 5 business days before start of profiling or
changing profile or operator
Inertial Profiler certification
Operator certification
Manufacturer’s recommended calibration and
verification tests
Within 2 business days after profiling engineer
approved test section
Cross correlation test results
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37. Submittals
Provide data within 2 business days after each day
of profiling
Profile data must include:
Raw profile data for each lane (ppf extension)
ProVAL ride quality analysis report in IRI for both wheel paths
ProVAL ride quality analysis report in MRI for each lane
ProVAL smoothness assurance analysis report in IRI for both
wheel paths
GPS data
Manufacturer’s recommended calibration and verification results
AASHTO calibration and verification test results
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38. Submittals
Provide data within 2 business days after each day
of profiling
Profile data must include:
Raw profile data for each lane (ppf extension)
ProVAL ride quality analysis report in IRI for both wheel paths
ProVAL ride quality analysis report in MRI for each lane
ProVAL smoothness assurance analysis report in IRI for both
wheel paths
GPS data
Manufacturer’s recommended calibration and verification results
AASHTO calibration and verification test results
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39. Smoothness Measurement
Contractor to notify Engineer of start location by
station and start time at least 2 business days
before profiling
Begin and end station will be marked on pavement
shoulder before profiling
Following “leave out” areas will be recorded
Begin and end of all bridge approach slabs
Begin and end of all bridges
Begin and end of all culverts visible on the roadway
surface
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40. Smoothness Correction
For HMA, if the final surface does not comply with
the smoothness acceptance values the contractor
can do the following:
Grind the pavement to within specified tolerances
Remove and replace it
Place an overlay of HMA
For PCC, if the final surface does not comply with
the smoothness acceptance values the contractor
can do the following:
Grind the pavement to within specified tolerances
Remove and replace it 40

41. QualityAssurance
Caltrans will independently collect profile data
For each 0.1 mile section, the contractor’s IRI
values must be within 10 percent of Caltrans’ IRI
values
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42. Collects data at a high rate of speed
(approx. 30 mph to 60 mph)
Collects data for both wheel paths
simultaneously
No traffic control
Safer
$$$$ Savings

43. ProVALReports
Ride Quality Analysis Report
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44. ProVALReports
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45. ProVALReports
Smoothness Assurance Analysis Report
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46. ProVALReports
46

47. ProVALReports
Profiler Certification Analysis Report
(Cross correlation test)
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48. CrossCorrelation Test
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Smoothpavements.com (FHWA)
Roadprofile.com (ProVAL)
CT Pavement Website
http://www.dot.ca.gov/hq/maint/Pavement/Offices/Pave
ment_Engineering/Smoother_Pavements.html
Equipment Suppliers
Ames Engineering (amesengineering.com)
Dynatest (dynatest.com)
Surface Systems and Instruments (Smoothroad.com)