INTRODUCTION
Historically,
the Department’s pavement smoothness specifications have been based on the
measurement of Profile Index (PI).
Devices called California Type Profilographs were used to measure PI,
and Pennsylvania Test Method (PTM) #424 defined which devices were acceptable
and described how to perform the measurements.
In order to assure
that pavement smoothness specifications result in a product that provides a
smooth ride for the motoring public, the Department will begin to base pavement
smoothness specifications on the International Roughness Index (IRI), rather
than PI, for projects let after July 1, 2000.
Whereas PI is a measure of the profile and the deviations from a smooth
plane, IRI simulates a vehicle’s response to the deviations and, thus, is an
expression of the “rideability” of the roadway. IRI is an indication of what vehicle passengers feel “in the seat
of the pants.”
Rather than the
profilographs used to measure PI, IRI is determined with devices called
“profilers.” Profilers are mounted with
laser sensors and computers and may either be vans that travel at highway
speeds, which the Department has been using for over a decade, or “Light Weight
Profilers” (LWP’s). An LWP is a golf
cart or all-terrain type vehicle that travels up to twenty miles per hour and,
due to its limited size and weight, and added maneuverability, can be used
within the confines of construction projects.
LWP devices will be used to determine pavement ride quality from the
longitudinal profile for acceptance and payment, based on the parameters
defined in the pavement smoothness specifications. (LWP devices can provide both IRI and PI data.)
PTM #428 has been
established to define the method in which to measure pavement profile using an
LWP device. This PTM is provided in
Appendix A. Unlike PTM #424, a list of
acceptable models is not included. That
is for two reasons: 1) the profiling technology is rapidly
expanding and it is not in the Department’s best interest to publish a PTM that
may constantly need to be updated to include new LWP manufacturers and models;
and 2) the Department wants to be assured that each individual LWP device is
operated proficiently and provides accurate and precise results, and not make
“blanket approvals” based on type.
It is with this
second reason in mind, that a program has been developed to verify that all LWP
devices are calibrated and operated properly. This program is directed and
controlled by the Department’s Bureau of Maintenance and Operations (BOMO),
Roadway Management Division, Roadway Inventory and Testing Section (RITS).
The second aspect of
the program is to certify that LWP operators are competent and capable of
operating the device, and collecting, analyzing, and reporting accurate
results. A certification program will
ensure control of the use of LWP devices, promote competence, proficiency, and
professionalism, and result in increased confidence in the test data. Furthermore, operator certification is
necessary because the Department offers no training for LWP operation. The vendors that supply LWP devices may
provide training, but the extent and quality of training is beyond the
Department’s control and will vary depending on the vendor, make, and model of
the LWP device.
It must be stressed
that the Light Weight Profiling System Calibration Verification And Operator
Certification Program is not a training program. It is expected that all participating operators are well versed
in the operation of the LWP device to be verified. The RITS staff will serve as technical experts, may provide
guidance during the certification process, but will not be responsible or
accountable for the training of LWP operators, even if they are Department
employees.
Furthermore, RITS
staff will verify the calibration of LWP devices, but cannot and will not be
responsible for making corrections or modifications to devices. Assistance and guidance may be provided, but
it is not the role of RITS to repair, maintain, or calibrate LWP devices. If repairs or modifications are necessary,
the owner of the device should contact the manufacturer. RITS will not initiate contact with any
manufacturer on behalf of an LWP device owner/operator.
The details of the
verification and certification program are defined in this document, as are the
Department contacts, test locations and logistics.
DEPARTMENT CONTACTS
The LWP Calibration
Verification and Operator Certification program is directed and controlled by
the Department of Transportation’s Bureau of Maintenance and Operations (BOMO),
Roadway Management Division, Roadway Inventory and Testing Section (RITS). The following individuals, with BOMO,
oversee and/or perform the operation:
J. Michael Long, P.E.
Chief, Roadway
Inventory and Testing Section 717-787-1153
Henry F. Lahr, Jr.
Manager, RMS Database
Support and Data Analysis Unit 717-783-0172
Thomas E. Leitzel
Manager, Pavement
Evaluation and Testing Unit 717-783-6857
Lawrence M. Stultz
Supervisor, Roughness &
Friction Testing 717-787-7291
Please contact Mr.
Leitzel to schedule LWP Calibration Verification and Operator Certification, by
calling the telephone numbers listed above, by facsimile (717-787-6013), or by
sending your request to:
Pavement
Evaluation and Testing
ATTN: Tom Leitzel
BOMO Annex
907 Elmerton Avenue
Harrisburg, PA 17110
SCHEDULING
RITS staff will
designate two weeks each year, in the Spring, to perform the operations of the
LWP Calibration Verification and Operator Certification program. All District offices, and all contractors
with an LWP device previously verified by RITS, will be notified. Also, any manufacturers, vendors, or
consultants that have indicated to RITS of their wish to participate in the
program will also be notified annually.
However, it is the responsibility of the LWP device owner to contact
RITS staff for scheduling.
ATTENTION: As part
of the calibration verification program, the LWP device operator will be required
to use the device’s software to perform an analysis of raw profile data
provided by RITS on a diskette and compute IRI values. The raw profile data will be in the format
required by the LWP device being verified.
Profiling technology is rapidly expanding, and the number of
manufacturers is expected to increase.
As stated previously, PTM #428 does not include a list of previously
accepted models. Therefore, RITS may not
have prior experience with all LWP device makes and/or models required to be verified. It is the responsibility of the
owner/operator to assure that RITS is informed of the LWP make and model, and
has the required file format, prior to the scheduled calibration verification. If necessary, the owner/operator shall
contact the manufacturer and assure that the required file format information
is obtained by Mr. Henry F. Lahr, Jr., of RITS. Mr. Lahr can be reached by calling 717-783-0172; information can
be sent to him by facsimile (717-787-6013), or by mailing to:
RMS Database
Support and Data Analysis Unit
ATTN: Hank Lahr
BOMO Annex
907 Elmerton
Avenue
Harrisburg,
PA 17110
RITS will not initiate contact with any manufacturer on
behalf of an LWP device owner/operator.
RITS will not schedule a calibration verification for an LWP
device that uses an unrecognized file format.
RITS will not accept an LWP
device which cannot properly analyze and produce correct results, based on raw
data provided on diskette during the calibration verification procedure.
After the conclusion
of the annually designated two-week period, subsequent verifications/
certifications will be performed by RITS as needed throughout the year. RITS will schedule an appointment within two
weeks of notification by the LWP device owner.
Reasons for the subsequent verifications/certifications include:
·
LWP devices acquired
after the annually designated period (see the previous “ATTENTION” statement)
·
Contractors not
previously verified that are awarded projects requiring a verified LWP device
·
New operators that
need to be certified
·
LWP devices or
operators that previously failed
·
LWP devices or
operators requested to be re-verified by Department personnel, due to
questionable results and/or practices on a construction or maintenance project
·
LWP devices that have
been repaired and/or hardware or software that has been replaced
Regardless of when an
LWP device is verified, it will only be valid for the remainder of the same
calendar year. However, operator
certifications are valid for the remainder of the issued calendar year, and for
the two subsequent calendar years.
In addition to
re-verifying LWP devices, RITS is also available to perform analysis of any
data collected by a previously verified device. If an LWP operator, or Department personnel choose to do so, raw
profile data can be sent to Mr. Lahr on diskette. When submitting the data, specify the make and model of the LWP
device used to collect the data, and a contact to receive the results. RITS will not analyze data collected by LWP
devices that have not participated in the calibration verification program.
If the RITS analysis
results in an IRI value that differs from that provided by the LWP device that
collected the data, that device’s acceptance will be revoked and a
re-verification must be performed.
SITE LOCATION
The
LWP Calibration Verification and Operator Certification site is located at
Harrisburg International Airport (HIA), which is approximately seven miles
Southeast of Harrisburg, PA. Since the
site is within the security limits of the airport, an escort is required at all
times. When scheduled for a
verification/certification, please to report to the BOMO Annex facility so that
RITS’ personnel can provide escort to the site and coordinate with the HIA
authorities. The BOMO Annex address is: 907 Elmerton Avenue, Harrisburg, PA 17110.
PROCEDURE
SCOPE
1.1 This document defines the procedure by which
the calibration of LWP devices will be verified in their measurement of the
International Roughness Index (IRI) of paved roadway surfaces. This procedure also will be the basis for
determining the operator’s overall understanding and proficiency of the
hardware and software of the device in order to acquire certification.
1.2 All LWP devices shall meet the definitions and requirements of Pennsylvania
Test Method (PTM) #428 – Method of Test for Measuring Pavement Profile Using A
Light Weight Profiler, provided as Appendix A.
The devices and operators shall be capable of providing results
accordingly and in the defined formats.
1.3 All test results shall be available in
either English or Metric units, as requested.
1.4 This procedure may involve the use and
exposure to hazardous materials, operations, and equipment. It is the responsibility of the operator to
establish and address all appropriate safety and health precautions prior to
commencement of this procedure.
OBJECTIVE
2.1 A test section will be established,
designated and maintained by RITS on an annual basis for the purpose of
verifying the calibration of LWP devices, the quality of test results, and the
proficiency of the operators.
2.2 RITS will annually determine a reference IRI
value for the test section. The test
section will be 528’ in length (as verified by a Department survey team). RITS will complete five passes with the
Australian Road Research Board (ARRB) Transport Research Walking Profiler. (The results of these five passes will be
compared to those of a rod and level survey performed by a Department survey
team.) If the standard deviation of the
five “ARRB” passes is within +/- 2% of their mean, then RITS will make five
passes with its LWP device. If the
standard deviation of the five “LWP” passes is within +/- 2% of their mean, and
the “LWP” mean is within +/- 2% of the “ARRB” mean, then the mean “ARRB” IRI value
will be established as the reference value.
2.3
During the
calibration verification program, RITS will provide a diskette containing raw
profile data formatted as required by the LWP device software. The operator shall use the LWP device’s
computer software to analyze the data on the diskette and compute an IRI value.
2.4
All LWP devices used
by the Department, or by contractor, shall be verified each year prior to use
on Department construction or maintenance projects. Furthermore, all operators of LWP devices shall be certified
prior to using the LWP devices on such projects each year. The owners of the LWP devices will be
responsible for the transport of the device(s) to the
verification/certification site, and for assuring that all necessary personnel are
certified.
2.5 All operators shall be well versed in the
operation of the LWP device to be verified, and be able to perform all tasks
associated with the verification/certification procedure.
2.6 All equipment manufacturer specifications
and manuals shall accompany the LWP device to be verified.
2.7 All LWP devices with acceptable test results
will be designated with a decal to be applied by RITS. The date of acceptance, and the number of
sensors will be denoted on the decal.
This decal shall be displayed at all times that the device is present on
a Department construction or maintenance project, and will be valid for no
longer than the remainder of the calendar year designated on the decal.
2.8
All certified LWP
operators will be provided a certification card. The name of the operator, employer, date of certification, and
the make and model of the LWP device used for the certification process will be
denoted on the card. Certified
operators may operate LWP devices other than the one used during certification,
but may only operate LWP devices that are the same make and model as that used
during certification, and only those designated with a valid verification
decal. This card shall be carried at
all times that the operator employs an LWP device on a Department construction
or maintenance project. The
certification will be valid for the issued calendar year, and for the two
subsequent years (as long as the LWP device is re-verified for those two
years).
2.9
If more than one
individual is to be certified for operating the same LWP device, then both
individuals shall perform the entire procedure separately. Upon acceptance, both individuals will be
certified.
2.10
If for any reason, an
LWP device is re-verified during the same year, an updated decal will be applied.
2.11
If for any reason, an
LWP device’s acceptance is revoked, the decal will be removed.
2.12
RITS will maintain
records of the results of the verification/certification program. The owner, make and model of the LWP device,
the name of the operator(s), and the date of acceptance or failure will be
included in these records, as will photographs of the LWP devices. RITS will periodically provide this
information to the Department’s Bureau of Construction and Materials
(BOCM). Only operators certified by this
program are eligible to operate the LWP devices that have been accepted.