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OCR for page 59
CHAPTER 4. DEVELOPMENT OF PROTOTYPE
QA PROGRAM
Introduction
The nrimarv task of developing a crototv~e OA Program for Me maintenance of
r J r ~ 1 A ~ - 1 ~
~ _ _ ~ ~ ~ ~ · .~ 1 · ~ e1 _ _ _ 11 _ _ ~ _ ~
highway facilities was undertaken toi~owmg tnorougn reviews or one co~ec~ea
literature and detailed evaluations of current highway agency quality programs. The
prototype program began as a collection of sound maintenance management and
maintenance quality practices, most of which formed We core of Me program.
Although the ideas and procedures behind some of these practices were modified to
better capture today's quality management precepts, over practices were readily
acceptable for inclusion as part of the prototype QA program.
, . ~
As bow new and old ideas of assessing, controlling, and assuring quality were
introduced Into Me core program, the prototype evolved into a flexible, multi-
component program, fully adaptable by interested agencies In two stages: development
and Implementation. By this point in Me development process, documentation of Me
various component principles, procedures, and interactions fell under the ensuing task
of Implementation Manual development.
This chapter describes the work conducted in developing He prototype QA
program for highway maintenance. It consists of several sections, beginning with a
discussion of Me work approach taken in developing Me prototype program. The
work approach section is followed by discourse on how various aspects of Me program,
such as the types of data required to run Me program and obtaining and using
customer input, were addressed during the development process. The final section
summarizes the QA program and briefly describes its transformation into an
implementation manual.
Work Approach
The basic idea In developing the prototype QA program was to establish a core set
of practices using the various tied-and-true management techniques unearned in the
literature review and agency surveys and introduce into that framework where
possible and practical new, effective quality management concepts. In essence,
yesterday's proven methods were to be infused with tomorrow's highly credible ideas.
Throughout the evolvement of the prototype program, a clear focus was maintained
on the goals of Me program. These goals consisted primarily of Me following:
· Maintain the highway network at an acceptable LOS based on all customer input
into maintenance activities.
59
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Develop m~nunum criteria for a QC process of daily maintenance operations to
ensure Cat operations are being conducted In an effective manner.
Provide a documented means of evaluating the condition of the highway system
and Me resources used to achieve an acceptable LOS.
· Improve the way In which highway maintenance operations are performed by
preventing problems that would have developed.
Several secondary goals were set forth to ensure Cat the prototype QA program
would receive maximum consideration from quality-seeking agencies. These program
goals included We following:
Functional in a centralized or decentralized management environment and In
both large and small agencies.
· Produces LOS ratings regardless of Me level of contract maintenance.
- Produces repeatable and reliable ratings for a variety of conditions and features.
Provides for customer involvement.
Cost effective to unplement.
A paramount regard in Me development of Me prototype program was Me need for
me ability to assess maintenance quality at Me network, project, and activity levels.
Each of these levels erases to some degree in highway agencies, and the ability to
manage from all Tree levels is a highly desirable and powerful feature. A brief
discussion of each maintenance level is provided below.
Network-leve! QA Refers to Me quality of Me maintenance management of an
entire highway system. This management originates at Me central office level
and fillers Trough to Me dis~ict/reg~on level and then Me subdis~ict/area
level. The prunary concern with network-level QA is appropriate allocation of
funds and Me establishment of network-w~de standards.
· Project-level QA Refers to Me quality of various maintenance activities applied
to a particular bridge or section of highway to keep it at a desirable LOS. The
maintenance acid ies perforated at this level are done as part of an approved
maintenance clan formulated during design or are done In order to bring
conditions among individual projects to more consistent levels.
· Activity-leve! QA This level of highway maintenance QA inclucles Me routine
activities performed by a maintenance crew and Nose activities Cat are done as
an immediate response to a change in conditions (e.g., snow and ice removal,
accident clean-up, guardrail repair). The most important aspect of this level is
making sure Cat Me end results of specific activities are consistent among
maintenance crews and are of high quality.
60
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Program Development
Development of Me prototype QA program proceeded largely in the fashion
originally planned. Several outstanding managerial and technical processes were
identified during the agency review process. The unclerlying principles and me~ods
of Dose processes were carefully examined to determine the extent to which they
conformed with basic quality tenets, such as focus on customers, use of statistical
process control (SPC) techniques, and instituting training. Several processes were
found to be well rooted in quality principles and were immediately embraced for use
in We prototype program. Others were found to be somewhat lacking and were
modified to better fit Me quality mind set.
At this stage of development, each process began to be viewed as an individual
component (or step) in an overall quality management program. The components were
then arranged in a logical sequence Mat included a program development phase and a
program implementation phase. In keeping win CQl principles, a portion of the
implementation phase was designed as a quality enhancement cycle that would allow
agencies to integrate new technologies and customer feedback, as wed as adjust to
changes In funding. The flow chart in figure 4 shows Me various components that were
used to define the prototype QA program, as well as the order in which they were
established. A brief discussion of each key component is provided below, whereas
complete details of all components are given in the QA program Implementation Manual.
· Key Maintenance Activities~roup~ng of key work activities into like
categories (i.e., maintenance elements) for Me purpose of evaluating
maintenance quality.
· Customer Expectations-The one-time collection of highway users'
expectations concerrung the LOS at which an agency should maintain its
highway system.
LOS Cr~ter~a~lear and measurable definitions concerrung the points at which
deficiencies cause maintenance features/characteristics to no longer meet
expectations. LOS criteria are usually expressed In terms of amount and extent
of deterioration (e.g., size and frequency of potholes, amount of litter per mile).
Weighting Factors Factors Cat (a) reflect Me relative importance of
individual maintenance feah~res/character~stics Mat comprise a maintenance
element and (b) reflect Me relative unportance of individual maintenance
elements that comprise a highway facility, on Me whole.
· Maintenance Pnonties Establishment of Me order In which work activities
will be conducted in Me event that a shortage of resources occurs. Each work
activity is prorated according to the four fundamental maintenance objectives,
prioritized as follows:
I. Safety of Me traveling public.
2. Preservation of Me ~n~reshnent.
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PHASE l-PROGRAM
DEVELOPMENT
Key Maintenance Activities and
Features/Ch; ~racteristics
-
Roadway Segment
Population and Sample
Segment Selection Process
LOS Data Collection,_ Develop LOS
Analysis, and Reporting_ Rating System _
Techniques
r Customer ~~~
| Expectations
~ LOS Criteria
|and Target LOS:
_ Weighting | l
Factors I
Agency Management | No
Maintenance
Priorities _ Approval
PHASE Il-PROGRAM
IMPLEMENTATION
Resource Funding
Pardal Request
(ZermBased
Budget)
FuD
Imple ment ~ogram
Prionties ~ Implementation
~ Emergenaes |
t Yes
Baselin~ng Existing
(Workload Inventory Process Updating (using
Estimate to Achieve ~baseline, current, and
Target LOS
_
Activity Cost Data
_g Agency \__
Monitoring r-
Formal LOS L
_ Inspections
I
QC of LOS I
Rating Teamsl
Figure 4. Prototype QA program flow chart.
62
target LOS's)
|Satisfaction |
~ .
~ LOS Analysis |
Land Reporting |
OCR for page 63
3. User comfort and convenience.
4. Aesthetics.
Baselining Existing LOS (Pilot Study) Determining the existing LOS of the
maintenance of Me agency's highway system using the components above.
Workload Inventory Information on We type, location, and dimensions of
key maintenance features Cat can be used to estimate potential workloads
for maintenance activities.
· Activity Cost Data Actual cost for performing a unit of work for a specific
e,
~ e , a ~ ~ ~ ~ ~ a ~ a a e Bad e ~ 1
activity. For agencies tnat no lUU percent or their work using agency employees,
this is usually readily available; however, for agencies Mat have a significant
mix of in-house and contract maintenance forces doing Me same activity, a
proportional blend of the cost data will be required.
Zero-Based Budge!-Application of Me activity cost data and field trial results
toward deterrnin~ng Me costs required to produce a specific TWOS established
from customer expectation input.
Formal LOS Inspections, Analysis, and Reporting Periodic maintenance
ratings stemming from random inspections of short segments of the entire
highway system maintained by an agency.
Customer Satisfaction The periodic assessment of how satisfied highway
users are with the LOS being provided by a maintenance agency.
The prototype QA program was designed to encompass Me maintenance elements
believed to be most common among highway agencies. These elements included
traveled roadway (i.e., mainline pavement), shoulder (paved or unpaved), roadside,
drainage features, traffic services, and vegetation and aesthetics. Because bridges and
snow and ice control were also recognized as substantial parts of several agency's
mamienance programs, methods for applying the QA program to these elements were
specially formulated.
Data Elements
Probably one of Me most important considerations of any program is Me type of
information required in order for the program to be properly administered. The ability
of supervisors to make sound managenal decisions is greatly strengthened when the
right kind of information is available to them.
The data elements considered to be essential or highly beneficial to Me QA program
were identifier! at Me outset of Me program development and consist of Me following:
· Assessments of highway customer expeciations~ustomer survey ratings of the
importance of various maintenance aspects on different facility types.
· Roadway features inventory-MMS listing of quantities, locations, and
characteristics of ma~ntenance-related roadway features/characteristics.
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· Internal assessments of maintenance quality Technical pass-fai! condition
ratings of various maintenance features/characteristics, such as guardrails and
pavement rutting.
· External assessments of maintenance quality~ustomer survey ratings of the
level of satisfaction win maintenance-related roadway features/characteristics.
Annual maintenance costs Total costs allocated and expended for a given year
for each maintenance activity performed by an agency.
Work accomplishments Productivity and resource (equipment, labor, and
materials) usage data on each maintenance crew.
Other Important data elements included Me documented costs ant! resource
requirements associated with operating the QA program.
Availability of Data from Other Management Information Systems
Determining Me availability of data in existing management information systems
was an Important task In Me development of Me QA program. If a considerable
amount of the data described In Me previous section was found to be available In other
management systems, such as PMS's and BMS's, and Dose data were accurate and
easily accessible, Den Me scope of Me LOS rating system might be drastically reduced,
since Me subject data could be extracted from Me appropriate management system
rather Man collected a second time In Me field.
During Me August 1995 field reviews of Me seven selected highway maintenance
agencies, none of Me agencies indicated incorporating data from other management
information systems into Weir LOS rating process. The general sense among Me
agencies was Cat data interchange was too difficult or inefficient, or Cat the data
contained in the over systems were not acceptable for use.
To further investigate this matter, Me data elements commonly containecl in four
different management systems PMS's, BMS's, SMS's, and Infrastructure management
systems (IMS's)-were examined. The sources for this process Included pavement
condition survey manuals and reports and bridge inventory manuals obtained from
several SHAs, conversations win key highway agency officials, and various pieces of
literature on infrastructure management. Summaries of Me findings pertaining to each
of Me four management information systems are provided In Me sections below.
Pavement Management Systems
A PMS is defined as an established, documented procedure Mat treats all of Me
pavement management activities- planning, budgeting, design, construction,
maintenance, monitoring, research, rehabilitation, and reconstruction In a systematic
and coordinates! manner. PMS's usually include condition surveys, a database of
pavement-related information, analysis schemes, decision criteria, and implementation
64
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procedures, all of which can be used to establish priorities for overlays, maintenance,
and allocation of funds; budget preparation; development of rehabilitation strategies;
and identification of problem areas. In essence, a PMS is a data bank for a network of
pavement sections (Peterson, 19871.
The element of a PMS considered to have Me most potential to serve as an input
interface for the QA program was pavement survey condition information. Typically,
four primary condition indicators are taken as part of a PMS. These are structural
capacity, friction, roughness/ride quality, and distress. Though highway agencies use
a variety of methods to collect condition indicator information and agencies key In on
different condition measures, they all share an overall objective of determining how
well pavements are performing.
The structural capacity of a pavement is today most commonly measured using
nondestructive deflection testing (NDT) techniques. A falling weight deflectometer
(LEWD) is used at selected locations throughout a pavement section to identify weak
areas, to estimate the strength of Me pavement system, and to predict the load-carrying
capability of the pavement section given the amount of traffic it experiences. Because
pavement maintenance actions provide little or no structural improvement, deflection
data were not considered to be suitable for use as Indicators of maintenance quality.
Pavement friction Is a safety-related condition measure that describes Me
slipperiness of a pavement surface. Most commonly expressed as a friction rating or
skid number, Me lower Me value, the more potentially hazardous the pavement is to
motorists. Application of skid numbers or friction ratings to the LOS rating system
may or may not be appropriate, depending on an agency's policy for correcting
slippery pavements. In some agencies, the prime responsibility for improving
pavements with low friction rests with maintenance, whereby they're tasked-through
Weir own forces or through contracted forces win applying surface treahnents or
mechanized patches or performing some sort of surface milling or grinding. In other
agencies, however, correction of slippery pavements is a rehabilitation action item and
Is privately contracted through over depalbllents within Me agency.
The ride quality or roughness of pavements is evaluated by many SHAs on an
annual or biennial basis using either a response-type measuring instrument, such as Me
Mays Ride Meter and the PCA Roadmeter, or an inertial profiling vehicle, such as the
South Dakota Profiler and the K.J. Law Profilometer.@ Both system types generate a
longitudinal roughness parameter, expressed as in/mi, for a specified length of
pavement section, with the latter type measuring the longitudinal profile of a pavement
and Men computing an international roughness index (~) based on the measured
profile and standardized vehicle response characteristics.
Although maintenance is obligated to correct various surface defects (bumps, holes,
dips, swells) that can collectively result in a rough ride, they are primarily concerned
with localized rough spots from Me standpoint of safety. Any bumps, holes, dips, or
65
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swells significant enough to cause a hazard to Be traveling public are under Me
immediate domain of maintenance. As a pavement becomes more and more
deteriorated, We amounts of these distresses become greater and greater. However, for
reasons of safety, the severity levels of the distresses will be kept somewhat in check
through proper maintenance.
The one data element of roughness/ride quality surveys that was found to have
potential use in He QA program Is He longitudinal profile measured by inertial
profilometers. These computerized profiles are usually stored for a time after
completion of a survey and may be available for visual examination. Though He
profiles are usually smoothed or filtered, He possibility exists Cat vertical deviations
identified In He computerized profile are indicative of localized defects Hat have not
been treated by maintenance.
The last type of pavement condition indicator data is distress. Evidence of distress
is manifested through various characteristics, such as cracking, rutting, and potholes in
asphalt pavement and spelling, cracking, and faulting in concrete pavement. Most
highway agencies perform either a visual or automated distress survey In order to
quantify He amount and severity of each distress type present In He pavement.
The correction or treahnent of distresses is not He full responsibility of
maintenance. Some distresses, such as fatigue cracking, rutting, or shattered slabs, are
He result of structural deficiencies and, when Hey occur on a large scale, must be
structurally improved through appropriate rehabilitation strategies. Nevertheless,
maintenance may be Involved in providing temporary fixes until a long-term
rehabilitation effort can be conducted.
Over distresses, such as bleeding, spelling, potholes, and bumps, require functional
improvements In order to restore adequate safety and, to a lesser extent, riding comfort.
Treatment of these types of distresses is usually provided by maintenance and,
therefore, the condition data for these distresses may be suitable for use as Indicators of
maintenance quality.
She over Hostesses, such as longitudinal and transverse cracking and joint seal
damage, are also largely He responsibility of maintenance. These types of distresses
are treated to preserve He pavement Investment (i.e., extend He life of He pavement).
Condition data for these types of distresses may also be applicable In He assessment of
maintenance quality.
The suitability of PMS distress data for use In He LOS rating system was found to
be dependent on many factors, the foremost of which include He following:
Frequency of pavement surveys Most PMS's entail annual (100 percent of
pavement sections sampled each year), biennial (100 percent of pavement
sections sampled every 2 years), or triennial (100 percent of pavement
66
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sections sampled every 3 years) surveys of a given facility type. For instance,
several SHAs, like Me Indiana and Wisconsin DOTs, perform annual surveys
of their interstate pavements and biennial surveys of Heir non-interstate
pavements. Since maintenance quality should at least be rated annually,
EMS data based on biennial or triennial surveys would not be adequate.
· Timing of pavement surveys Pavement management distress surveys are
often performed In the spring and early summer to avert He busy
.
construction schedule. LOS inspections, on the other hand, may be done
routinely win little regard to yearly seasons or construction/maintenance
seasons, or they may be done at selective times of He year. Any attempted
linkages between He two systems must take into consideration He need for
· e , e e
consistency In nnung.
Length of pavement survey segments-LOS sample segments will generally
range between 0.1 and I.0 mi (0.16 and 1.61 km). PMS survey scents may
, _ ~ . . - . . . ~
, ~ ~
range from 10(} it (3u.5 m' to the entire length or a pavement section (which
could be several miles). If Here is to be a linkage between He two systems, a
common length must be established.
· Availability of desired data Several highway agencies only collect key
distress data, such as cracking, rutting, and patching. In such instances, He
possibility of using PMS data for a more complete assessment of maintenance
quality is substantially reduced.
Accuracy of data and type of pavement surveys PMS distress data are
collected In a myriad of fashions, ranging from visual surveys of randomly
selected samples to automated continuous surveys. For PMS data to be
useful In He LOS ratings, He information must be collected from He same
sample units as He LOS ratings and the condition surveys must be objective,
accurate, and repeatable.
Should an agency be able to overcome the above linkage obstacles, it slid must
consider He nature of He PMS digress data collected. The agency must first review
each distress type and decide if maintenance has an obligation to correct * or whether,
by policy, it is a distress Hat is "out of maintenance's hands."
Bridge Management Systems
The Bridge Inspector's Tranung Manual (FHWA, 1991) states:
In 1971, the National Bridge Inspection Standards (NBIS) came into being. The
NBIS se! national policy regarding bridge inspechon frequency, inspector
qualifications, reportformats, and inspection and ratingfonnats. Because of the
requirements that must befulfilledfor the NBIS, it is necessary to employ a
uniform bridge inspection reporting system. A uniform reporting system is
essential in evaluating correctly and efficiently the condition of a structure.
Furthermore, it is a valuable aid in establishing maintenance priorities and
replacement pnonties, and in determining structure capacity and the cost of
67
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~ - ~
maintaining the nation's bridges. The information necessary to make these
defe~inations must come largely from the bridge inspection reporting system.
ConsequeniZy, the importance of the reporting system cannot be overemphasized.
The success of any bridge inspection program is dependent upon its reporting
system.
The NBIS requires that Me findings ant! results of a bridge Inspection be recorded
on standard forms. Although He Structures Inventory and Appraisal Sheet (SINAI shown
in figure 5 Is not a stanciard form, it represents a list of bridge data that each State must
perioclicaDy report to FHWA for ah public structures within its inventory. Many SHAs
have developed Heir own standard forms using He SI&A sheet as a guide.
A considerable effort has been made by the FHWA to make the information and
knowledge available to accurately and thoroughly Inspect and evaluate bridges.
Through He manuals developed by FHWA and training courses taught by He National
Highway Institute (NHI), a major effort has been accomplished to standardize He
complex issue of bridge inspection.
As He areas of emphasis in bridge inspection programs change due to newer types
of design and construction techniques, He guidelines for inspection must also be
modified to Increase uniformity and consistency. A primary use of the inspection
reports is to provide guidance for immediate foDow-up inspections or corrective
actions. These reports provide information that may lead to decisions to limit or deny
He use of any bridge determined to be hazardous to public safety.
Deficient bridges are divided into two categories: structurally deficient and
functionally obsolete. Generally speaking, structurally deficient bridges are weight-
restricted due to condition, are in need of rehabilitation or, in rare instances, have been
denied access by He public. Functionally obsolete bridges are normally structurally
sound but do not meet current standards for deck geometry, clearances, or approach
alignment.
At He close of He inspection, He bridge inspector must use his experience to
document inspection deficiencies Cat have been observed. A Borough and well-
documented inspection is essential for making informed and practical
recommendations to correct bridge deficiencies. A well-prepared bridge inspection
report not only provides information on existing bridge conditions, but it also serves as
an excellent reference source for future inspections.
The accuracy and uniformity of information ~ tal to He management of an
agency's bridge program. QC is He enforcement tool used on a daily basis to ensure
He inspection conclusions and recommendations are based on correct information.
Many States are assigning He final review and signing of inventory results to the chief
inspector, who should be a professional engineer or have a minimum of 10 years
experience in bridge inspection. Quality assessment is usually accomplished by
68
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NATI ONAL BRI OGE I NVE~ORY -
*~**~*~** IDENTIFICATION *~*~***~**
( 1 ) STATE NAME - CODE
( 8 ) STRUC, URE NUMBER #
( S ) I NVENTORY ROUTE ( ON/UNDER ) - =
(2) STATE HIGHWAY DEPARTMENT DISTRICT
3 ) COUNTY CODE _ ( 4 ) Pl ACE CODE
(6) FEATURES INTERSECTED - ( 112)
( 1 ) fACI LITY CARRI ED - ( 104 )
( 9 ) LOCAT I ON - ( 26 )
11 ) MI LEPOINT ( 100 )
16) LATITUDE _ ~ _ . ' (17) LONGITUDE D _~(~01)
98) BORDER BRIDGE STATE COOK _ ~ SHARE X ( 102)
9 ) BORDER BRIDGE STRUCTURE NO . # ( 103 )
(~10)
(2Q)
(21)
(22)
(371
*** STRUCTURE TYPE AND MATERIAL ****~****
(43) tTRUCTURE tYPE MAIN: MATERIAL
TYP E - CODE
(44) STRUCTURE TYPE APPR: MATERIAL
TYP" - CODE
NUMBER OF SPANS IN MAIN UNIT
NUMBER OF APPROACH SPANS
(45]
( 46 ) NUI'It~K US Mr~nu^~n ton
(1G7) DECK STRUCTURE TYPE - CODE_
t 108) WEARING SURFACE / PROTECTIVE SYSTEM:
A) TYPE OF WEARING SURFACE
8 ) TYPE OF .~BRANE
C) TYPE OF DECK PROTECTION
CODE _
CODE _
CODE
a********* AGE AND SERVICE ******~****~***~*~**
(27) YEAR BUILT
1Q6) YEAR RECONSTRUCTED
(42) TYPE OF SERVICE: ON
UNDER -CODE
~ 28 ) ACHES: ON STRUCTUREUNDER STRUCTURE
(29) AVERAGE DAILY TRAFFIC
( 30 ) YEAR OF AOT 19
( 19 ) BYPASS, DETOUR LENGTH
~09) TRUCK ADT _ X
MI
LENGTH OF MAXIMUM
STRUCTURE LENGTH
CURB OR SIDEWALK:
****~***** GEOMETRIC DATA **~***********~****~*
SPAN Fr
__ LEFT ._ FT RIGHT . FT
BRIDGE ROADWAY WIDTH CURB TO CURB . FT
FT
(48)
(49)
(50)
( 5- ) -^ ~-- · ~ _ # ~
(52) DECK WIDTH OUT TO OUT
( 32 ) APPROACH ROADWAY WIDTH (~/SHOULDERS )
( 33 ) BRIDGE MEDIAN - CODE _
(34) SKEW _ DEG (as) STRUCTURE FARED
(10) INVENTORY ROUTE MEN YERT CLEAR ~IN
(47) INVENTORY ROUTE TOTAL HORIZ CLEAR .
(S3) MIN VERT CLEAR OVER BRIDGE RONY _ F1 _ IN
(54) MIN VER1. UNDERCLEAR REF ~ _ _ FT_ IN
(as) MIN LAT UtlDERCLEAR RT REF ~ _ . FT
( 56) MI?. LAT UNDEPtCLEAR LT . FT
***a****** NAVIGATION DATA ********
(38) NAYIGAT$0N CONTROL ~ CODE (90)
111) PIER PROTECTION ~COt)E _ (92)
(39) NAVIGATION VERTICAL CLEARANCEFT A)
116) VERT-LIFT BRIDGE HAY MIN VERT CLEAR= FT B)
( 4Q) NAVIGATION HORIZONTAL CLEARANCEFT C]
STRUCTURE INVENTORY AND APPRAISAL -/OD/YY
**~******~*~*~*****~**~**~****~*~*~*
SUFFI CI ENCY RATING =
STATUS =
a**** CLASSIrlCATIt)N ************ CODE
NSIS BRIDGE LENGTH ~
I GHWAY SYSTEM ~
FUNCTIONAL CLASS -
DEFENSE HIGHWAY -
PARALLEL STRUCTURE
DIRECTION OF TRAFFIC
TEMPORARY STRUCTURE
DESIGNATED NATIONAL NETWORK -
. TOLL -
t~tAIHTAI ~ -
OWNER -
HISTOQICAL SIGNIFICANCE
*~*~*~* CONDITION **~*~**~* CODE
( 58 ) DECK
( 5g ) SUPERSTRUCTURE _
( 60 ) SUBSTRUCTURE _
( 61 ) CHANNEL & CHANNEL PROTECTION
( 62 ) CULYERtS
******* LOAt) RATING AND POSTING *a****** CODE
(31 ) DESIGN LOAD ~ _
(64) OPERATING RATING ~ ~~
( 66) INVENTORY RATING ~ =
( 70 ) BRIDGE POSTING ~ _
(41) STRUCTURE OPEN, POSTED OR CLOSED ~ _
DESCRIPTION ~
*******a APPRAISAL *** CODE
( 67 ) STRUCTURAL EVALUATION
(68) DECK GEOMETRY
(69) UNDERCLEARANCES, VERTICAL ~ HORIZONTAL
( 71 ) WATERWAY ADEQUACY
( 72 ) APPROACH ROADWAY ALIG -
( 36 ) TRAFFI C SAFFrY FEATURES
(113) SCOUR CRITICAL BRIDGES
****** PROPOSED IMiROVEMENTS **********a
(7S) TYPE Of WORK - CODE
(76) LENGTH OF STRUCTURE IMPROVEMENT
(94) BRIDGE IMPQOY~ENT COST
(95) ROADWAY IMPROY~ENT COST
( 96 ) TOTAL PROJECT COST
(97) YEAR OF IMPROVEMENT COST ESTIMATE
t 114 ) FUTURE AOT
(115) YEAR OF FUTURE ACT
S 000
S -000
S' ,' ',000
19J20_
i**** INSPECTIONS **
INSPECTION DATE _ / _ t 91 ) Frequency ~
CRITICAL FEATURE $NSPECTI~: (93) CEl DAY
FRACTURE CRIT QUAIL - - _ ~A) _/
UNDERWATER INSP - = - _ ~8) _/
OTHER SPECIAL INSP - - ~C) _/
Figure 5. FHWA structure inventory and appraisal sheet (FHWA, 1991).
69
I,
it.
,..
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Despite being more qualitative than quantitative, attribut~based statistical QA was
judged to be the more appropriate methodology for the present time, and therefore was
chosen for use in He prototype QA program. Although Be method of variables better
captures the spins of CQI, Me vast majority of highway agencies would be unable to
apply this method because of its much greater demand for resources, particularly
labor-hours.
A second consideration of statistical applications in LOS field inspections was We
method used to compute LOS ratings. In current maintenance rating programs, a
percentage statistic is computed for each feature/characteristic by summing the
number of segments in which a given feature/characteristic met He standard and Hen
dividing it by He total number of segments. He resulting statistics for each
feature/character~stic are Hen combined win venous feature/characteristic weights
and element weights to produce an overall LOS rating.
In the prototype QA program, an LOS rating is computed for each sample roadway
segment using He established feature/characteristic weights and element weights. An
overall LOS rating is Hen determined by computing the statistical mean. This
approach allows an agency to determine He variance and standard error in He ratings
which, In turn, can be used to calculate future sampling requirements. The details of
this computational approach are given in the following section titled "LOS Analysis."
a
A third consideration of statistics In LOS field inspections pertained to He need for
a pilot field study, or a trial run of LOS inspections. A pilot study provides insight
about the inherent variability of LOS ratings, which can then be taken into
consideration when determining He required sample size for (future) formal LOS
inspections. For a given confidence level and precision, greater variability In LOS
ratings results In a higher number of roadway segments to be sampled.
Pilot studies were noted as having been performed by He Virginia, Maryland, and
Florida DOTs during He implementation phase of Heir quality assessment programs.
However, a pilot study is not entirely necessary, as a statistical formula exists that
allows computation of He required roadway sample size based on a specified
confidence level and precision. Unfortunately, the price for guaranteeing precision and
being able to do without a pilot study is an increase In sample size. Even for sizeable
variability in LOS ratings (standard deviation of 3 to 4 percentage points), considerably
larger sample sizes would be required by foregoing a pilot study.
Since a pilot study has He makings to serve as He first formal round of LOS
inspections He number of samples taken In He pilot may satisfy He requirements for
formal LOS inspections or can be supplemented win additional samples and because
considerably fewer samples are likely to be required in comparison with nonpilot-
based sampling, a pilot field study was advocated In the prototype QA program. The
results of He pilot inspection round can serve as a baseline of existing maintenance
conditions from which future improvements in maintenance quality can be measured.
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A fourth aspect of statistics in LOS field inspections was We sample segment
selection procedures and Me corresponding sampling rates. As win customer surveys,
a sound sampling process was developed to help implementing agencies determine the
required number of sample segments to inspect, given a desired precision and
confidence level and a preliminary estimate of Me variance In LOS ratings.
Reviews of Me sampling procedures used by Florida and Maryland indicated Mat
sampling requirements in these agencies' programs are determined periodically using
the statistical bootstrap method, a relatively sophisticated resampling procedure that
uses no explicit formulas in relating population size, sample size, confidence level, and
precision. This approach to determining sample size was considered impractical as
most implementing agencies would need to seek Me assistance of a statistician. To
keep Me sampling process as simple as possible' a basic formula Ocular to one used
by Virginia-was identified which could be used by those individuals leading the QA
program implementation effort. The formula was proposed in the Implementation
Manual and is as follows:
z2 X ~
n=
n
where: n = required sample size.
s = standard deviation of Me ratings from Me pilot study.
~ = desired precision.
z = z-statistic (for 95 percent confidence, z=~.96~.
Eq. 3
It Is clear in this formula Mat Me necessary sample size increases as Me desired
precision increases. That is, if one wants more precise results (smaller value of d), then
a larger sample swe is required.
The method recommended in Me prototype QA program for selecting roadway
sample segments was simple random sampling, performable through a random
number generator function available In most statistical or spreadsheet computer
software. This method assures each individual segment In Me total roadway
population Me same chance of being chosen for field inspection.
Recognizing Me need to obtain adequate sampling representation among various
roadway subsets, Me option of stratifying (i.e., subdividing) Me total roadway segment
population was also featured in the prototype QA program. The stratification could be
according to geography (district, residency, maintenance unit)' facility type (functional
class, highway system), or any combination Hereof, with simple random sampling
carried out for each strata. It was recommended Mat Me total number of strata be
limped to 10, since Me added benefit associated wad more Man 10 was considered to
be marginal in comparison with the cost of increased sample sizes. The precedence for
stratified sampling in maintenance quality assessment is well established, with Me
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OCR for page 80
LOSS =
Virginia DOT stratifying by highway system (interstate, primary, secondary highways),
the Maryland DOT by county (23 total), and Me Florida DOT by bow maintenance unit
(30 total) and functional classification (urban limited access, rural limited access, urban
arterial, rural arterial).
T..05 Ar~a~
As discussed previously, Me computation of an overall LOS rating under Me
prototype QA program entails computing individual l.OS ratings for each sample
segment and Men calculating Me statistical mean and variance. These calculations are
made using equations 4 and 5, shown below.
L
n
where: LOSS = mean segment LOS.
LOSsi = individual segment LOS values for n sample segments.
n = number of sample segments.
s2 -
-
where: s2 = sample variance of segment LOS ratings.
LOSsi = individual segment LOS values for n sample segments.
LOSs = mean segment LOS.
n = number of sample segments.
(LOSsi- LOSs)2
no
Eq. 4
Eq. 5
The standard donation and We appropriate confidence interval are Men computed
using equations 6 and 7 Oven below.
s = Is2
Eq. 6
where: s = standard deviation of segment LOS ratings.
s2 = sample variance of segment LOS ratings.
fOSs+(zxs/In) Eq.7
where: LOSs = mean segment LOS.
z = z-staUstic (~.96 for 95 percent confidence, 2.8 for 99.5 percent
confidence).
s = standard deviation of segment LOS ratings.
n = number of sample segments.
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If the LOS of a highway facility, as a whole, is to be analyzed, then a 95-percent
confidence coefficient (i.e., z equal to 1.96) is recommended in equation 7. However, if
~. . . ~. .
individual highway elements are to be examined to Determine which elements cause a
facility to be deficient, Men a higher level of confidence (99.5 percent [z = 2.81) is
required. The higher confidence coefficient is necessary because multiple confidence
intervals (one for each element) are being constructed for examination.
OA of LOS Rating Teams
Since most implementing agencies are likely to establish multiple LOS rating teams
(i.e., satellite teams), a QA process for ensuring accurate (i.e., consistent and unbiased)
rating results from all teams was deemed essential to the prototype QA program. Two
alternatives for performing annual QA checks of satellite teams were identified, one
based on analysis of variance and We other based on two-sample z-tests.
The analysis of variance approach entailed having each satellite team individually
inspect a common set of randomly selected roadway segments. The variability of
segment ratings, both within teams and between teams, is calculated and a statistical
determination made as to whether significant differences in ratings exist among the
teams. If significant differences were not found to exist, then the teams would be
consistent and no further analysis would be necessary. If, on the other hand, significant
differences were found to exists Men Me teams whose ratings differed from Me
collective team rating would require adjustments in their rating process in order to
bring Weir ratings in compliance with consensus ratings.
The two-sample z-test approach entailed having a central-office rating team an
ideal team, whose ratings are considered accurate perform field inspections In each
satellite team's domain. A cannon set of randomly selected roadway segments are
independently inspected at Me same time by bow Me central-office team and Me
satellite team. The paired ratings from all sample segments are Men statistically
analyzed via Me z-test In order to determine if Me satellite team's ratings are
significantly different from the central-office team's ratings. If not, then the satellite
team would be in compliance with the central-office team and no further analysis
would be necessary. If so, Men Me satellite team would require adjustments In Weir
rating process in order to bring their ratings into compliance with the central-office
team.
The preferred method of QA checks on LOS rating teams was the two-sample z-test.
This method was considered easier from a field coordination and execution standpoint,
and it involved simpler statistical calculations. Just as important, however, was the fact
that key personnel from the QA program administrative staff would remain active in
the LOS rating system and could possibly identify areas of improvement. The complete
set of steps for conducting z-test QA on LOS rating teams is detailed In Me
Implementation Manual.
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Customer Input
A major part of Me modern-day quality movement is recognition of Me customer's
needs. The Demoing philosophy defines quality as "whatever We customer wants"
(Miller and Krum, 1992~. However, because not all customers want Me same Ming and
because customers' wants and needs change over time, it Is necessary to continuously
assess and measure customer satisfaction.
For maintenance agencies, of course, Me primary customers are Me highway users.
Most everything a maintenance agency does is a service to Me traveling public,
whether it's of direct notice to Hem (like keeping the highway system safe,
comfortable, and attractive) or is substantially less perceptible (like keeping He system
structurally sound). Since the customers are paying a substantial part of He bill for
maintenance through highway user taxes, it is only appropriate to ask or solicit their
· ~
op~uons.
Win more and more emphasis being placed on He customer, solicitation of
customer input was made a key albeit, optional-component of He prototype QA
program. The combination of knowing the level to which customers want the highway
cut v
system Initially kept (customer expectations) and He levels to which they're satisfied
over time (customer satisfaction) allows an agency to make He proper adjustments In
maintenance effort.
The inclusion of customer input into He prototype program prompted
consideration of two main items. First, He method most suitable for soliciting
customer opinions needed to be selected. Second, the detailed procedures for carrying
out He selected methoc! needed to be established.
As discussed in chapter 2, several methods have been or are currently being used to
solicit customer Input. These include focus Croups, formal and informal surveys,
--rid c7----r-#~ , ~
~ ~ ~ . ~ ~ ~ ~ ~ . ... ~ ~ ~
customer panels, and formal and informal teeanacx ores. l-nou~n eacn
method has advantages and disadvantages, only formal questionnaires, conducted by
mail or telephone, were judged appropriate for determirmag highway users,
expectations of service. These types of surveys, when properly constructed and
adm~rustered on a statistical basis, yield the most reliable and representative customer
inputs. The over techniques usually result In considerably biased, qualitative, or
inadequate input. A Bird type of formal questionnaire survey- personal
interviews-generates useful and reliable information, but was found to involve
extremely high costs.
-a r
Table 12 highlights some of He important facets of two recent customer surveys,
One conducted by the Minnesota DOT to determine both customer expectations and
customer satisfaction and He over conducted by He Pennsylvania DOT to deter~rune
customer expectations. This information reveals much about He resources required to
obtain reliable customer input. It also illustrates some of the key differences between
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OCR for page 83
Table 12. Key facets of Minnesota (SMS, 1994) and Pennsylvania
(Pennsylvania DOT, 1993) customer surveys.
Minnesota
Pennsylvania
Mine Conducted
Source Listing
Pretest
Sampling Type
November 1994.
Telephone listing.
Focus group.
April 1994.
Pennsylvania Driver's License database.
·
Disproportionate stratified random sample
(based on 1990 Census of Minnesota
County populations and aggregated into
eight maintenance districts).
N/A
Random sample (using random number
generator).
Survey Type
Sample Size
Formal telephone questionnaire survey of
customer expectations and customer
- satisfaction.
1,200 originally proposed phone interviews
(300 in each of 2 districts and 100 in
each of 6 districts), 1,244 actual phone
interviews. 10% of households contacted
refused to participate, and less than 2% of
the respondents terminated their
participation in the survey midway.
Formal mail-in questionnaire of customer
expectations only.
4,800 mailed out (400 in each of 12
counties); 1,018 properly completed
responses for 21~% overall response
rate.
1~.
Cost
Timeframe and Staff
61 total questions, Minute phone time.
$40,000 (approximately $32/respondent).
2 weeks using several telephone survey staff
(responses entered directly into computer
at time of survey).
25 rating questions, 1 page.
$20,000 (approximately $20/respondent).a
1.5 months using three in-house
individuals committed part time.a
N/A
a
Not available.
Pennsylvania conducted a customer satisfaction survey shortly after Me customer expectations survey. The
back-to-back surveys were conducted over a Month timeframe at a reported combined cost of $40,000.
mail-in and telephone surveys, such as the cost of the surveys and the time frame and
staffing needed to complete Me surveys.
The development of procedures for conducting mail-in and telephone surveys
Occurred in four key areas: statistical sampling, questionnaire development, in-house
. ~. ~. ~
testing of the questionnaire, and format conduct or tne survey. As discussed previously
. . ~· ~- ~
in this chapter, random sampling and suatlnea random sampling were found to be the
most conducive sampling methods. Win Me ideal survey population defined as "users
of Me highway facilities maintained by Me agency," appropriate source listings to
represent Me survey population were identified based on Me experiences of various
SHAs, including Maryland, Pennsylvania, Oregon, and Minnesota. State Depardnent
of Motor Vehicles (DMV) or Driver's Licensing Bureau (DEB) agencies were considered
Me best sources, as Me records maintained by these entities typically include Me names
of inHi~ririll~lc lir~n~H to drive or prorate vehicles within Me State alone with Me
~ . ~ 1
corresponding phone numbers and mailing addresses.
-, ~
Telephone listings are also considered a viable source. This type of source listing is
easier to access but is considerably more biased Man Me two previous lists because of
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OCR for page 84
Me potential for households win no telephone or win an unlisted number (it should
be noted Cat random-digat dialing [RDD] is a technique Cat can be used to eliminate
Me bias associated win unlisted telephone numbers). To reach Me right customers and
limit bias, Me phone interviewers can ask to survey Me licensed driver in Me
household wad Me most recent birthday, as was done by a surrey consultant for Me
Minnesota DOT (SMS, 1994~.
In the design of maintenance questionnaires, it was determined Cat Me most
appropriate way to measure Me importance of or satisfaction win various maintenance
work items Is to use rating scale questions. Scales of 1-5, I-10, and I-100, win ~
representing "not Important" and 5, 10, or 100 representing "very unportant," are
effective means of measuring customer expectations and satisfaction, particularly when
Me questions are posed in simple terms to which Me customer can relate (e.g., potholes,
smoothness, visibility). Refraining from Me use of technical questions, such as "what
degree of reflectivity is acceptable for striping?" is also important. The traveling public
is most valuable in defining what it expects when traveling on Me highway system, but
it is the job of Me professionals In Me agency to work out technical issues.
To maintain as high a response rate as possible and We highest degree of
consideration for Me questions, questionnaires must be kept short and concise. A I- to
3-page mail-~n survey or a 5- to 10-m~nute phone survey is usually sufficient for asking
Me questions pertinent to customers' expectations or satisfaction. On mail-in surveys,
Me survey form must be made attractive (proper text arrangement, spacing, and style)
so Cat participants are more receptive to Me survey.
As was pointed out by Kopac (1991), "Regardless of how carefully Me questionnaire
has been worded, it should not be assumed that it win work wed until it has been
tested under field conditions." Hence, informally pretesting Me survey on non-
professionals was emphasized, as it will provide useful feedback on the clarity,
interpretation, and logical sequencing of Me questions, as well as Me length,
receptiveness, and effectiveness of me survey.
O ,
The decision of whether to administer Me questionnaire survey by mad! or by
telephone is largely clependent on costs and Me availability of staff and over in-house
resources. Again, table 12 shows Me costs, time frame, and staffing Cat were required
for conducting Me Minnesota telephone and Pennsylvania mail-~n surveys. This
information, along win samples of each agency survey, were featured In Me
Implementation Manual.
Adjusting to Improvements in State of the Art
Many advancements In highway maintenance have been made in Me last half
century. These advancements were spawned by Me desires of maintenance
practitioners, researchers, and ~ndus\Ty personnel to make operations safer and more
84
f
OCR for page 85
cost-effective, and to make highway features last longer. The advancements have come
in Me way of new materials (and new formulations of existing materials), new
equipment (and modifications to existing equipment), and new technologies, and Weir
acceptance into practice has been made possible through on-the-job training,
demonstrations, instructional workshops, experiments, and research reports and
symposiums.
Future advancements In highway maintenance are certain to occur, and training and
education of employees is essential if continuous unprovement is to be sustained. For
this reason, employee training was made a key component In me prototype QA
program. Training helps provide employees win me proper skills and knowledge to
do their jobs right. And when jobs are done right, the quality of the service or product
· · ~
IS improved.
Several important ideas about employee training were recognized In Me
development of this program component. First was Me idea Mat an employee's
resistance to change is often rooted in Me lack of appropriate skills or resources.
Although a poor attitude may be a part of Me problem, it Is more likely Mat an
employee wishes to do a good job, but simply lacks Me knowledge or tools to
accomplish it.
Another important aspect Mat was recognized was ensuring that employees become
familiarized win Me work issues so Hey understand Me Importance of Heir job
function. Training employees to think about He work Hey perform, why it's
perfonned, and ways in which it could be improved, creates greater potential for
technology advancements for the agency and promotes motivation and self-esteem for
He employees.
A third aspect Hat was considered unportant In He educational process was
communication. Because He natural tendency of most employees is to do He best job
Hey can win very little complaining, some employees' need& be Hey new
equipment, improved work skills, or additional staff may go unaddressed.
Eventually, Heir work performance can suffer, giving rise to internal disputes. By
instructing employees In He art of communicating with peers and supervisors and
resolving small problems initially, a major step can be taken In avoiding major conflicts
down He road.
Quantifiable and Replicable Results
Consistency and repeatability of ratings should be a significant concern of any
unplemendug agency. Without He QC function being performed throughout He
implementation process, He ratings Hat are produced will most likely be challenged.
To prevent major issues being made of LOS ratings, formal LOS training and a pilot
field study were made major components of He QA program. These programs will
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help familiarize LOS raters with the rating process and will provide an estimate of the
inherent variability of ratings among teams (if Were is more than one) once a
reasonable level of consistency has been achieved throughout training. Although
variability must be expected among the LOS ratings, it is important to minimize it to
acceptable limits and then document it for later use in determiriing the required sample
size for formal LOS field inspections.
The objective of Me LOS training component is to make sure that raters look at the
same features In each case and arrive at He same basic conclusions concerning Weir
evaluations. Having a good description or specification of when a
feature/characteristic meets or exceeds desired conditions is a key factor in this phase.
Success in establishing this critenon will enable an agency to begin establishing He
credibility of its QA system, whereas a lack of proper descriptions may have He
opposite effect and cause further efforts to be ineffective.
The objective of He pilot field study is to determine He variability of ratings among
He different rating teams. Win an initial estimate of He variance among teams, He
required number of sample segments to be rated during He formal inspection process
can be calculated for a given precision and confidence level.
The QA/QC process for LOS rating teams, which was touched upon earlier, also
helps effect consistent rating results. If a team's ratings become statistically
significantly different from He central-office team's ratings, Den actions are
immediately taken to bring Bat team's ratings into line wad He central-office team's
ratings. The actions may include helping He team deter~riine which
features/characteristics are present at a Even sample segment or reinforming Rem of
how a certain condition standard is Interpreted.
Pros and Cons of Implementation
Why should any agency consider abandoning past management practices and set
out on a new direction for its maintenance operations? The answer can be very
straightforward; it shouldn't if it has accomplished He following goals:
Assurance Hat its highway maintenance and operations meet or exceed the
expectations of He traveling public.
Has a good relationship win He groups (e.g., highway commission, Governors
office, legislature, county/city commissioners) having final say over agency
budget requests.
· Obtained adequate funding for agency maintenance needs.
· Provided equal LOS for all components of He highway system.
· Provided employees win the skills and equipment to accomplish assigned tasks
In a cost effective and efficient manner.
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Agencies that have not met most of these goals make prime candidates for installing
the prototype QA program, the main advantages of which include the following:
~ ~ _ ~ ~
Identification of customer expectations concerning Me LOS at which Hey wish
We highway system to be maintained.
Identification of the key activities involving workloads necessary to accomplish
He desired LOS.
· Ability to document and transmit to field forces He amount of deficiencies
allowable before an activity no longer meets the desired LOS.
· Ability to identify factors Hat reflect He relative Importance of individual
maintenance features/charactenstics and Heir unpack on He highway facility as
a whole.
· Establishment of a maintenance work priority system, showing which work win
be performed first in He event of funding shortfalls or in emergency situations.
· Ability to monitor He actual LOS being achieved In each category or work
activity within a maintenance unit, region, or district.
· Ability to identify locations Hat have extra resources (labor, equipment, and
materials) or need additional resources in order to accomplish established LOS.
Ability to produce budget requests showing He e~asJdug LOS, He
proposed/desired LOS, and the funding required to achieve and maintain the
desired LOS.
Ability to measure customer satisfaction win He LOS being provided.
Establishment of a uniform LOS in all management areas widen He
maintenance and operations group.
At He same time, highway agencies enticed by these numerous benefits must
consider He foHow~ng disadvantages in implementing He prolotvae OA program:
, ~_ ~
Permanent change in management philosophy and attitudes towards the
commitment to the agency's maintenance and operations workforce and how
work is accomplished.
Cost of developing, Implementing, and monitoring LOS goals.
Potential employee, union, and special-interest concerns with the development
and implementation of LOS criteria.
cat ~
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Representative terms from entire chapter:
los ratings
