NCHRP Project 20–07/Task 357 A GUIDE TO COLLECTING, PROCESSING, AND MANAGING ROADWAY ASSET INVENTORY DATA FINAL REPORT Requested by: American Association of State Highway and Transportation Officials (AASHTO) Standing Committee on Highways Subcommittee on Maintenance Prepared by: Kathryn A. Zimmerman, P.E. Kartik Manda Applied Pavement Technology, Inc. 115 West Main Street, Suite 400 Urbana, Illinois 61801 June 2015 The information contained in this report was prepared as part of NCHRP Project 20-07, Task 357, National Cooperative Highway Research Program. SPECIAL NOTE: This report IS NOT an official publication of the National Cooperative Highway Research Program, Transportation Research Board, National Research Council, or The National Academies.
73
Embed
A GUIDE TO COLLECTING, PROCESSING, AND MANAGING …sp.maintenance.transportation.org/Documents/NCHRP 20-07_task 357 A... · A Guide to Collecting, Processing, and Managing Roadway
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
NCHRP Project 20–07/Task 357
A GUIDE TO COLLECTING, PROCESSING, AND MANAGING ROADWAY ASSET INVENTORY DATA
FINAL REPORT
Requested by:
American Association of State Highway and Transportation Officials (AASHTO)
Standing Committee on Highways Subcommittee on Maintenance
Prepared by:
Kathryn A. Zimmerman, P.E. Kartik Manda
Applied Pavement Technology, Inc. 115 West Main Street, Suite 400
Urbana, Illinois 61801
June 2015
The information contained in this report was prepared as part of NCHRP Project 20-07, Task 357, National Cooperative Highway Research Program.
SPECIAL NOTE: This report IS NOT an official publication of the National Cooperative
Highway Research Program, Transportation Research Board, National Research Council, or The National Academies.
ACKNOWLEDGMENTS
This study was requested by the American Association of State Highway and Transportation Officials (AASHTO), and conducted as part of the National Cooperative Highway Research Program (NCHRP) Project 20-07. The NCHRP is supported by annual voluntary contributions from the state Departments of Transportation. Project 20-07 provides funding for quick response studies on behalf of the AASHTO Standing Committee on Highways. The report was prepared by Applied Pavement Technology, Inc. The work was guided by a task group which included Tanveer Chowdhury, Virginia DOT; William D. “Bill” Drake, Jr, Louisiana DOTD; Christopher C. Harris, Tennessee DOT; Thomas J. Kazmierowski, Golder Associates; Mary A. Martini, Nevada DOT; Roger E. Smith, Texas A&M University (retired); Lonnie R. Watkins, North Carolina DOT; and Nastaran Saadatmand, FHWA. The project manager was Amir N. Hanna, NCHRP Senior Program Officer.
DISCLAIMER The opinions and conclusions expressed or implied are those of the research agency that performed the research and are not necessarily those of the Transportation Research Board or its sponsoring agencies. This report has not been reviewed or accepted by the Transportation Research Board Executive Committee or the Governing Board of the National Research Council.
NCHRP Project 20-07/Task 357
A GUIDE TO COLLECTING, PROCESSING, AND MANAGING ROADWAY ASSET INVENTORY DATA
FINAL REPORT
Requested by:
American Association of State Highway and Transportation Officials (AASHTO)
Standing Committee on Highways Subcommittee on Maintenance
Prepared by:
Kathryn A. Zimmerman, P.E. Kartik Manda
Applied Pavement Technology, Inc. 115 West Main Street, Suite 400
Urbana, Illinois 61801
June 2015
The information contained in this report was prepared as part of NCHRP Project 20-07, Task 357, National Cooperative Highway Research Program.
SPECIAL NOTE: This report IS NOT an official publication of the National Cooperative
Highway Research Program, Transportation Research Board, National Research Council, or The National Academies.
A Guide to Collecting, Processing, and Managing Roadway Asset Inventory Data Final Report
PROJECT OVERVIEW ................................................................................................ 1 RESEARCH SCOPE AND TASKS .............................................................................. 1
Task 1: Summarize the State of the Practice ........................................................... 1 Task 2: Identify Trends ............................................................................................. 2 Task 3: Develop Guidance ....................................................................................... 2
Task 4: Prepare Documentation ............................................................................... 2 DISTRIBUTION OF RESEARCH PRODUCTS ........................................................... 3
CHAPTER 2 – SUMMARY OF PRACTICE .................................................................... 4 INTRODUCTION ......................................................................................................... 4 TECHNOLOGY BEING USED TO ESTABLISH ASSET INVENTORIES .................... 4
AVAILABLE REFERENCES ON BUILDING AN ASSET INVENTORY ....................... 5 Data Collection Techniques ..................................................................................... 5
LiDAR ....................................................................................................................... 8 Data Quality ............................................................................................................. 9
STATUS OF ASSET INVENTORIES IN STATE DOTS ............................................. 10 Drainage Assets ..................................................................................................... 11
A Guide to Collecting, Processing, and Managing Roadway Asset Inventory Data Final Report
ii
LIST OF FIGURES
Figure 1. Inventory status of drainage assets (NCHRP 2015) ..................................................... 11 Figure 2. Inventory status of roadside assets (NCHRP 2015) ..................................................... 12 Figure 3. Inventory status of pavement assets (NCHRP 2015) ................................................... 12
Figure 4. Inventory status of traffic assets (NCHRP 2015) ......................................................... 13 Figure 5. Inventory status of special facilities (NCHRP 2015) ................................................... 13
LIST OF TABLES
Table 1. Suitability of different methods of data collection (Zimmerman and Stivers 2007) ....... 6
A Guide to Collecting, Processing, and Managing Roadway Asset Inventory Data Final Report
iii
AUTHOR ACKNOWLEDGMENTS
The research report herein was performed under NCHRP Project 20-07, Task 357 by Applied
Pavement Technology, Inc. (APTech). Ms. Kathryn A. Zimmerman, P.E., served as the
Principal Investigator for this study. She was assisted by Mr. Kartik Manda, an Engineering
Associate at APTech.
ABSTRACT
This project was initiated by the National Cooperative Highway Research Program to develop
guidance for establishing and managing roadway asset inventories. The resulting Guide, which
was written as a standalone document, can be used by transportation agencies to help make
informed decisions on the type of technology most appropriate for collecting asset inventory
information and the considerations that must be taken into account for processing and managing
the data. The study concentrated on both manual and automated data collection approaches,
including manual surveys, photogrammetric methods, and remote sensing technology (e.g.,
mobile LiDAR).
The Guide includes considerations that should be evaluated during all phases of establishing or
updating an asset inventory. First, the Guide addresses technical considerations that should be
taken into account regardless of the data collection selected, such as developing criteria for
classifying assets and developing data collection standards. Secondly, the Guide presents factors
to consider in determining the appropriateness of each of the three technologies used in
collecting inventory data. This section includes factors such as the level of accuracy required
and the visibility of the asset from the road. Next, the Guide includes considerations for
collecting the data, including differences depending on whether the data will be collected using
in-house personnel or an outside contractor. Finally, the Guide suggests considerations for
managing the data effectively, including topics such as storage requirements and update
schedules.
A Guide to Collecting, Processing, and Managing Roadway Asset Inventory Data Final Report
1
CHAPTER 1 – INTRODUCTION
PROJECT OVERVIEW
Over the past decade and since the passage of recent legislation (commonly known as Moving
Ahead for Progress in the 21st Century Act or MAP-21), there has been an increasing emphasis
on the use of performance data to drive agency investment decisions as part of a comprehensive
asset management program. While inventory and performance data has been collected on
pavement and bridge assets for many years, there is less consistency in the status of roadway
asset inventories for other assets such as guardrails, culverts, and signs.
National Cooperative Highway Research Program (NCHRP) Project 20-07, Task 357 was
initiated in 2014 to develop guidance for establishing and managing roadway asset inventories
among state Departments of Transportation using current technology. This document represents
the Final Report for the project. It summarizes the project activities and documents the
assessment of current practice that was conducted during the early stages of the project. The
information gathered from this activity served as the basis for developing the Guide, which is
presented as a standalone document as an attachment to this Final Report. The Guide considers
both manual and automated technologies and includes factors that highway agencies should
consider when deciding which approach to use for building its asset inventory. Once the
decision is made, the Guide includes recommendations for making the best use of the technology
for collecting, processing, and managing roadway asset inventory data, such as guardrails, tower
lighting, signs, and drainage features. It is important to note that the Guide does not address the
performance criteria that are often used to monitor the level of service being provided to the
traveling public or to prepare maintenance budgets. Although the Guide focuses primarily on
building, maintaining, and managing asset inventories, the same technology can often be used to
evaluate asset performance. As a result, many of the same considerations identified for
establishing an asset inventory are relevant to the process of assessing the condition of these
assets.
RESEARCH SCOPE AND TASKS
The project objective was to develop practical guidance that could be used by highway agency
practitioners for collecting, processing, and managing roadway asset inventory data. This
objective was accomplished through the completion of the four tasks described below.
Task 1: Summarize the State of the Practice
The project began with a series of activities designed to provide a good understanding of the
state of the practice. One of the activities included a literature search of the readily available
documentation on collecting, processing, and managing roadway asset inventories. One of the
major sources of information included the results from NCHRP Synthesis 470, titled
Maintenance Quality Assurance Field Inspection Practices (NCHRP 2015). The preparation of
the synthesis included the conduct of a survey into the practices in state highway agencies for
collecting inventory information on a variety of different types of assets (e.g., culverts,
sidewalks, fences, pavement shoulders, and signs). This information proved to be very useful in
determining the status of asset inventories and the methods used to collect the information.
Information from the synthesis is included in Chapter 2 of this report.
In addition to reviewing reports and other forms of documentation, the project team conducted
interviews with both data collection vendors working in the state data collection market and state
A Guide to Collecting, Processing, and Managing Roadway Asset Inventory Data Final Report
2
DOT practitioners who have used different forms of technology to establish asset inventories.
The information from the interviews influenced the development of the Guide and some of the
information is used to illustrate the considerations identified.
At the conclusion of Task 1, a summary report was prepared and distributed to the project’s
Technical Panel for review and comment. The feedback provided by the Technical Panel was
also instrumental in shaping the Guide’s content.
Task 2: Identify Trends
The information obtained during Task 1 served as the basis for identifying trends in the asset
inventory information being collected by state agencies and the methodologies being used.
Additionally, the interviews with state practitioners provided a good understanding of the factors
that influenced the selection of a technology for building their asset inventories. The states
selected to be interviewed represented a range of data collection methodologies, including both
manual and automated approaches. The trends that were observed are incorporated into the
Guide.
Task 3: Develop Guidance
During Task 3, the research team used the information obtained during Tasks 1 and 2 to develop
the framework for creating the Guide. The Guide, which is presented as an attachment to this
Final Report, addresses the following four steps associated with collecting, processing, and
managing asset inventory data:
Step 1: Getting ready to select a methodology – This step includes the organizational
issues that need to be addressed to assess an agency’s needs. This step involves deciding
what assets to include in the inventory, identifying the users of the data, determining the
level of detail needed, and establishing the characteristics that will be used to describe
each asset.
Step 2: Selecting a methodology – Using the information obtained during step 1, the
second step involves selecting the most appropriate methodology to meet the agency’s
needs. The decision is based on a number of different factors, related to the visibility of
the asset from the road, the level of detail needed, safety considerations, the potential for
collaboration with other data collection activities, and available resources.
Step 3: Collecting the data – Immediately before and during the data collection processes,
steps need to be taken to ensure the quality of the data. This step includes the activities
involved in securing a data collection vendor (if appropriate), establishing test sites to
verify the technology provides the necessary data, and monitoring the quality of the data
throughout the data collection process.
Step 4: Processing and managing the data – The final step involves processing the data to
extract the necessary information and ensuring that the data is updated on a regular cycle.
This step contains the factors that must be taken into consideration to ensure the best
possible use of the information within the agency.
Task 4: Prepare Documentation
The last project task involved preparing this Final Report, which includes the guidance described
earlier.
A Guide to Collecting, Processing, and Managing Roadway Asset Inventory Data Final Report
3
DISTRIBUTION OF RESEARCH PRODUCTS
This document was developed primarily for maintenance personnel in state DOTs responsible for
developing and maintaining a roadway asset inventory. It is designed to assist these individuals
in determining the type of technology most appropriate for building and maintaining the
inventory, the technical and organizational considerations that should be addressed prior to
building the inventory, and the data processing and management issues that should be addressed
with each of the different forms of technology. The considerations described in the Guide are
not unique to practices in state DOTs; therefore, the information provided in this document can
be equally useful to maintenance personnel in cities, counties, or other transportation agencies.
In addition to maintenance personnel, other practitioners may benefit from the information
provided in this Guide. For instance, the information may help an agency that is using
automated equipment for pavement management data collection find new uses for the digital
images that are being collected. Similarly, an agency that is using a vehicle equipped with
LiDAR for collecting inventory information may discover new applications for the technology to
support the agency’s design activities.
In addition to making this report available through the NCHRP website, the information
contained in this document will be distributed to practitioners through technical presentations at
meetings such as the Transportation Research Board (TRB) Annual Meeting and meetings of the
American Association of State Highway and Transportation Officials’ (AASHTO)
Subcommittee on Maintenance. Opportunities to present the information through webinars
and/or workshops will also be sought.
A Guide to Collecting, Processing, and Managing Roadway Asset Inventory Data Final Report
4
CHAPTER 2 – SUMMARY OF PRACTICE
INTRODUCTION
An agency’s ability to make sound, defensible investment decisions relies in part on the
availability of a comprehensive asset inventory, a method of assessing current conditions and
performance, and tools for evaluating the impacts of different investment strategies on network
performance. Establishing an inventory is a fundamental step in establishing an asset
management program.
This chapter introduces the manual and automated technologies that are commonly used to
establish asset inventories and documents the use of the technology in practice. The chapter also
summarizes the status of asset inventories in state highway agencies, as documented in a
synthesis of practice and from phone calls with maintenance practitioners. It concludes with the
emerging practices identified from the literature and as part of the interviews with data collection
vendors.
As much as possible, the summary of practice focuses on the technology used for collecting,
processing, and managing roadway asset data. A great deal of information is also available on
assessing the condition and performance of roadway assets, but that information was considered
to be outside the scope. However, similarities in the technology used for establishing an
inventory and conducting a condition survey exist. For instance, cameras and other equipment
can be added to the vans used for conducting pavement management surveys to facilitate the
extraction of asset inventory data (AASHTO 2006).
The information obtained through the investigation into current practices, including the
interviews with state DOT practitioners, provided much of the basis for the information
contained in the Guide.
TECHNOLOGY BEING USED TO ESTABLISH ASSET INVENTORIES
There are several different methodologies being used to collect inventory information and to
assess the condition of roadway assets. These techniques range from manual surveys that use
“processes where people are directly involved in the observation or measurement of pavement
surface properties without the benefit of automated equipment (McGhee 2004)” to automated
surveys that involve “data collected by imaging or by the use of noncontact sensor equipment
(McGhee 2004).” Today’s manual surveys often take advantage of hand-held computers and
other forms of technology that have greatly improved the efficiency of data collection and
processing activities. Data collected using automated methods can be evaluated using software
tools that automate the extraction and interpretation of the data (commonly referred to as fully
automated) or through semi-automated methods that require some human interaction to extract or
interpret the data. Some agencies are also using mobile imaging with or without Light Detection
and Ranging (LiDAR), a three-dimensional (3-D) technology that can rapidly acquire a great
deal of highly-detailed geospatial information. Each approach has certain advantages and
disadvantages, which may include some of the following (McGhee 2004):
Manual data collection techniques are most appropriate for assets that are not readily
available from the travel lanes. Traditionally, the methodology is slow and safety of the
crews may be an issue, but the recent use of hand-held computers for recording survey
information has increased the efficiency of this process.
A Guide to Collecting, Processing, and Managing Roadway Asset Inventory Data Final Report
5
Automated (or mobile) data collection techniques allow multiple assets to be assessed at
the same time while traveling at traffic speeds. However, the assets must be visible from
the travel lane and the equipment typically requires specialized equipment and operators.
Automated processing allows large amounts of data to be available quickly, but the
interpretation is constrained by the computer’s ability to recognize certain types of assets
and their characteristics.
Semi-automated processing is slower than automated processing, but it provides for
human interpretation of data from the field in a safe, workstation environment.
Mobile LiDAR data can be collected quickly and with high accuracy for 3-D mapping,
but the amount of data collected can require substantial resources to process.
AVAILABLE REFERENCES ON BUILDING AN ASSET INVENTORY
Data Collection Techniques
Recognizing that an asset inventory is a key component to a comprehensive asset management
program, AASHTO developed the Asset Management Data Collection Guide to address the data
collection needs associated with asset management (AASHTO 2006). This reference documents
the struggles transportation agencies have had to collect, store and analyze comprehensive
inventory data for non-pavement and non-bridge assets and the advances that have occurred with
handheld mobile computing devices in conjunction with Geographic Information Systems (GIS).
The report also provides guidance on prioritizing the assets to include in the inventory based on
asset category, rank, and relative importance to the agency (AASHTO 2006). Other factors, such
as asset value, the availability of data collection protocols, the ease of evaluation, the overall
value to users, and data collection frequency, are also factors to consider when prioritizing
assets. For those items included in the inventory, the report outlines the necessary decisions to
assess the condition of the asset, including the method of assessing performance, the level of
detail and accuracy needed, inspection frequency, and sampling strategy.
A separate study conducted for NCHRP investigated the use of asset management principles for
managing ancillary assets other than pavements and bridges. Included in the report is a hierarchy
intended to serve as the basis for classifying information on these assets, which includes asset
class, asset elements, and sub-elements as appropriate (Rose et.al. 2014). The report also
provides guidance for managing signs, traffic signals, markings, barrier systems, and lighting
with information for establishing the inventory, assessing conditions, and estimating service life.
The AASHTO Asset Management Data Collection Guide compares the advantages and
disadvantages associated with manual, mobile and satellite data collection techniques (AASHTO
2006). For instance, manual data collection methods are reported to be relatively accurate and
they allow access to assets that are not visible from the road; however, the process can be slow
and labor intensive (AASHTO 2006). It also exposes agency personnel to safety hazards caused
by interactions with traffic. The Guide identifies the collection of multiple data items at traffic
speeds as an advantage to mobile data collection processes (AASHTO 2006). However, it is
only suitable for assets that can be seen from the road and it requires special equipment that often
forces agencies to contract out the data collection services. The suitability of different data
collection methods for various types of assets was documented by Zimmerman and Stivers
(2007) and is presented as Table 1.
A Guide to Collecting, Processing, and Managing Roadway Asset Inventory Data Final Report
6
Table 1. Suitability of different methods of data collection (Zimmerman and Stivers 2007).
The AASHTO Asset Management Data Collection Guide indicates that it might be cost-effective
for state highway agencies using automated technology to collect pavement condition
information to begin extracting asset inventory data for some assets from the images that are
collected. It also identifies the manual method as the most commonly used method for
establishing a roadway asset inventory and assessing asset condition (AASHTO 2006).
The feasibility of using automated equipment for building roadway inventories was documented
in an NCHRP report that describes the use of technology for georeferencing the data (NCHRP
2000). A 2004 NCHRP Synthesis describes the use of automated data collection devices in state
highway agencies (McGhee 2004). A survey conducted for the synthesis found that the most
commonly employed methods of automated data collection make use of acoustic or laser sensors,
and image-processing tools. At that time, digital imaging was reportedly preferred over analog
imaging techniques (McGhee 2004).
In 2005, the FHWA conducted a case study to document the techniques being used by eight state
highway agencies to manage roadway safety hardware, such as longitudinal barriers, crash
cushions, attenuators, end treatments, breakaway supports, and work zone hardware (FHWA
Asset
Categories Asset Types
Data
Collection
Method
Asset
Categories Asset Types
Data
Collection
Method
Drainage Culvert Manual Traffic Items Signal Manual
Curb and gutter Manual Sign Manual or
Mobile
Sidewalk Manual Pavement markings Manual or
Mobile
Ditch Manual Pavement marker Mobile
Drop inlet and storm
drain
Manual Overhead sign structure Manual or
Mobile
Erosion control Manual Traffic barrier/median
barriers
Manual
Under or edge drain Manual Highway lighting Manual or
Mobile
Roadside Fence Manual or
Mobile
Guardrail &
Attenuators
Guardrail Manual or
Mobile
Grass mowing As Needed Guardrail end treatments Manual or
Mobile
Brush As Needed Impact attenuator Manual or
Mobile
Landscaping Manual Other Facilities Tunnels Manual
Sound barrier Manual Rest areas Manual
Pavement Shoulder Manual or
Mobile
Weigh stations Manual
Lane, paved Manual or
Mobile
Roadside Graffiti Manual
Lane, unpaved Manual or
Mobile
Roadside Litter Manual or
Mobile
A Guide to Collecting, Processing, and Managing Roadway Asset Inventory Data Final Report
7
2005). The study found that the New Mexico Department of Transportation (DOT) used an
automated vehicle to capture right-of-way images for its state-maintained roadway safety assets.
The inventory is updated, and conditions assessed, by field personnel equipped with hand-held
computers with Global Positioning Satellite (GPS) features. In the office, a “Virtual Drive” was
set up to enable agency personnel to view highway segments and to determine the adequacy of
signage, guardrail treatments, and other roadway hardware. The report indicates that the other
seven states also use right-of-way images to build their asset inventories and handheld devices to
collect condition information. The report concluded that the use of right-of-way imagery and
GPS coordinates at a workstation was a common approach to establishing an asset inventory
among state agencies and that manual data collection methods were more commonly used to
collect condition information on these assets (FHWA 2005).
The use of automated and manual data collection techniques for collecting information on
roadway safety hardware was discussed with participants as part of a peer exchange on Asset
Management and Safety. Meeting participants reported that most were using manual field
inspections in combination with one or more additional data collection methods (FHWA 2011).
For example, the report indicates that surveys for night retroreflectivity of signs could be done
manually in conjunction with automated surveys featuring GPS capabilities to improve location
accuracy. The feasibility of using LiDAR to inventory roadway assets was also discussed, but
participants indicated that the cost-effectiveness of the technology had not yet been
demonstrated.
The Asset Management and Safety Peer Exchange participants reported that lack of resources
had been an obstacle to having data available on all safety assets. They indicated that they often
had robust inventories for signals, signs, guardrails, and lighting, but little information on road
edge delineators, for example (FHWA 2011). They also discussed the level of detail required for
inventorying and assessing the condition of safety assets and reported that they often had trouble
effectively using all the data collected. The most pressing issues identified by the Peer Exchange
participants concerning their safety asset inventories included (FHWA 2011):
Location referencing accuracy and consistency.
Temporal referencing accuracy and consistency.
Availability of trained personnel.
Availability of tools and systems in order to integrate safety-related asset data with other
data.
A Peer Exchange conducted in 2009 with state maintenance personnel indicates that manual data
collection techniques for inventorying and assessing the condition of roadway assets are used
most often, even though their agencies were using automated techniques for pavement distress
surveys (Adams et al. 2009). The participants in the peer exchange expressed interest in some of
the new technological advancements (e.g., LiDAR), but questioned the cost-effectiveness of the
technology.
A domestic scan that was conducted in October 2011 investigated best practices for collecting
and reporting highway maintenance performance information (NCHRP 2012). The participants
confirmed that most participants were using some type of manual survey to collect maintenance
inventory and condition information. However, some of the participants reported that
technology had advanced to the point that it could improve the efficiency of data collection
A Guide to Collecting, Processing, and Managing Roadway Asset Inventory Data Final Report
8
activities. For example, the Utah DOT reported on a pilot study they had conducted that showed
that data collected using handheld devices as part of their manual surveys could be collected as
quickly and as accurately as data collected with automated data collection vans (NCHRP 2012).
In a study conducted for the North Carolina DOT, the Institute for Transportation Research
Education at North Carolina State University compared the results of both manual and mobile
data collection techniques to establish a roadway asset inventory (Cunningham et al. 2013). The
results indicate the mobile data collection vehicles located roadway assets accurately, as long as
there were no obstructions from landscaping or other vehicles (Cunningham et al. 2013). Mobile
data collection methods were reported to show promise for accurately identifying feature
characteristics, such as asset type, and measurements of asset height and road grade were
measured within allowable tolerances. These devices were found to be less accurate with
measurements parallel to the direction of traffic, such as offset distance or width. There were
also several point features, such as drop inlets or attenuators, which proved to be difficult to
georeference (Cunningham et al. 2013).
An ongoing Strategic Highway Research Program 2 (SHRP2) study compared the accuracy of
data produced by mobile imaging techniques with data collected from a manual inventory of
eleven different roadway attributes. The initial findings indicate that there is a high degree of
agreement between the two approaches in terms of the total number of items counted, but less
accuracy in identifying the geospatial location of each item (Smadi 2014).
LiDAR
The use of LiDAR in transportation agencies was explored in a report prepared by the Wisconsin
DOT (WI DOT 2010). This study documents applications for three types of LiDAR, including
airborne, mobile, and terrestrial LiDAR. It explores applications in surveying, highway design,
PURPOSE OF THIS GUIDE ........................................................................................ 1 GUIDE ORGANIZATION ............................................................................................. 1 GUIDE FOCUS ............................................................................................................ 2 USING THE GUIDE ..................................................................................................... 2
CHAPTER 2 – DATA COLLECTION METHODS ........................................................... 3
ADDITIONAL READING MATERIAL ......................................................................... 12
CHAPTER 3 – GUIDELINES ........................................................................................ 14 STEP 1: GETTING READY TO SELECT A METHODOLOGY .................................. 15
Select Assets to Include in the Inventory ............................................................... 15
Determine Resource and Other Constraints .......................................................... 17 Identify Users ......................................................................................................... 17
Establish a Data Dictionary .................................................................................... 18 STEP 2: SELECTING A METHODOLOGY ............................................................... 19
Evaluate Asset Visibility from the Road .................................................................. 19
Identify Other Data Collection Efforts ..................................................................... 21 Summary ................................................................................................................ 22
STEP 3: COLLECTING THE DATA ........................................................................... 22 Secure Data Collection Equipment and/or Vendor ................................................. 22 Develop Data Collection Protocol ........................................................................... 23
Conduct Personnel Training and Equipment Calibration ........................................ 24 Conduct Quality Control and Acceptance Testing .................................................. 25
STEP 4: PROCESSING AND MANAGING THE DATA ............................................. 25 Develop In-House Technical Expertise .................................................................. 25 Formulate Data Processing Procedures ................................................................ 25 Provide Access to Data .......................................................................................... 26 Address Organizational Issues ............................................................................... 27
Implement Data Governance Standards ................................................................ 27 Develop Plans for Inventory Updates ..................................................................... 27
Other Considerations ............................................................................................. 28 EXAMPLE .................................................................................................................. 29
The Scenario .......................................................................................................... 29 The Process ........................................................................................................... 29
ACCELERATING THE LEARNING CURVE .............................................................. 30 Challenges and Possible Remedies ....................................................................... 31 Benefits Realized ................................................................................................... 31
ADDITIONAL READING MATERIAL ......................................................................... 32
A Guide to Collecting, Processing, and Managing Roadway Asset Inventory Data
ii
CHAPTER 4 – FUTURE DIRECTIONS ........................................................................ 33 FUTURE MODIFICATIONS TO THE DATA COLLECTION PROCESS .................... 33
ADVANCEMENTS IN DATA PROCESSING TECHNIQUES .................................... 35 SUMMARY ................................................................................................................ 35 ADDITONAL READING MATERIAL .......................................................................... 36
APPENDIX A – SAMPLE DATA DICTIONARY ..........................................................A-1
APPENDIX B – TYPICAL CONTENT IN A DATA COLLECTION RFP ......................B-1
A Guide to Collecting, Processing, and Managing Roadway Asset Inventory Data
iii
LIST OF FIGURES
Figure 1. Characteristics associated with manual data collection techniques. .............................4 Figure 2. Extract from a manual data collection form used by the Alabama DOT
ata%20Collection%20Form.pdf). .................................................................................5 Figure 3. Characteristics associated with photogrammetry. ........................................................9 Figure 4. Characteristics associated with mobile LiDAR. .........................................................11 Figure 5. Guidelines for developing or updating a roadway asset inventory. ............................16
Figure 6: Relation between decision making levels and detail and amount of data required
(Flintsch 2006). ...........................................................................................................18 Figure 7: Relative comparison of resource requirements, data utility, and costs (not to scale). .....21 Figure 8. Factors in selecting a methodology for building a roadway asset inventory. .............22 Figure 9. Screenshot of New Mexico RFI spatial map with assets identified (Hensing and
A Guide to Collecting, Processing, and Managing Roadway Asset Inventory Data
A-1
APPENDIX A – SAMPLE DATA DICTIONARY
Attenuators – Energy absorbing barriers which provide protection from vehicles striking rigid bodies such as bridge columns and barrier walls.
LRS to reference Log mile location of front nose of attenuator.
GPS to reference GPS location of front nose of attenuator.
Feature Type 04
Feature Char Choose from the following types
00758 - GREAT
00759 - TRACC
00760 - Quadguard
00761 - Hex-foam Sandwich
00762 - React
01330 - TAU-II
01331 - SCI
01332 - HEART
01333 – QUEST
Feature Location Choose from the following locations
1-Left
2-Right
4-Median Right
6-Median Left
7-Centerline
Height Report tallest height to nearest 0.1 feet. Measure vertically from the ground to the top of the attenuator
Width Report widest point to nearest 0.1 feet.
Length Report length to nearest 0.1 feet. Measure linearly along the centerline of the attenuator from the front nose to the point where the attenuator connects to
A Guide to Collecting, Processing, and Managing Roadway Asset Inventory Data
A-2
the rigid body that it is protecting.
Notes Only permanent installations shall be inventoried. Attenuators used for construction shall be excluded.
Attenuators located along the center of the roadway or at the end of median barrier walls shall be coded as Feature Location = 7-Centerline.
If an attenuator is found that does not match any of the examples provided, contact the State Project Manager.
Flat-Sheet Signs – A roadway sign which is fabricated using thin aluminum sheeting and a reflective sheeting to display directions and instructions to drivers. Flatsheet Signs are normally less than five feet in either width or height and do not contain reinforcing ribs on the back side.
LRS to reference Log mile location of the sign.
GPS to reference For ground-mounted signs, GPS will reference edge of sign closest to roadway (signs in right shoulder reference bottom left edge of sign, signs in left shoulder reference bottom right edge of sign). For overhead signs, GPS will reference center of bottom edge of sign.
Feature Type 06
Feature Char
The 5-digit code that corresponds to a specific MUTCD code will be entered (to be provided by the State)
Feature Location Choose from the following types
1-Left
2-Right
3-Overhead Right
4-Median Right
5-Overhead Left
A Guide to Collecting, Processing, and Managing Roadway Asset Inventory Data
A-3
6-Median Left
7-Centerline
Feature Condition Choose from the following conditions
1-Poor: Sign may be damaged or non-reflective to the point that it cannot be clearly read by traffic. It may also be out of plumb enough that it is not legible.
2-Fair: Sign is clearly visible, mostly reflective, may have minor damage that does not interfere with the intended message of the sign, may be out of plumb, but still readable by traffic.
3-Good: Sign is clearly visible, reflective, free of damage, and plumb.
Sign Orientation Choose from the following
1-North
2-South
3-East
4-West
5-Northeast
6-Northwest
7-Southeast
8-Southwest
Sign Mount Type Choose from the following
01 Grnd Single Post-U shape
02-Grnd Single Post-square tube
03-Grnd Double Post-U-shape
04-Grnd Double Post-square tube
05-Grnd Double Post-W-beam
06-Grnd Triple Post-U-shape
07-Grnd Triple Post-square tube
08-Grnd Triple Post-W-beam
09-Bridge Mounted
10-Cantilever Overhead
11-Truss Bridge Overhead (This will include normal truss bridges intended solely for signs)
Comments Enter the sign legend (Anything not denoted by the MUTCD code such as speed limit value for speed limit signs or other text like town names).
Height Report height of sign to nearest 0.1 feet. Use the standard size that matches closest to the measurement; otherwise record to the closest inch. All measurements will be converted to feet before delivery.
A Guide to Collecting, Processing, and Managing Roadway Asset Inventory Data
A-4
Width Report width of sign to nearest 0.1 feet. Use the standard size that matches closest to the measurement; otherwise record to the closest inch. All measurements will be converted to feet before delivery.
Notes Legend that is written in the comments will follow rules put forth in Appendix A to ATTACHMENT E.
Digital signboards will not be extracted. Only permanent sign installations will be collected, construction signs will be excluded.
A Guide to Collecting, Processing, and Managing Roadway Asset Inventory Data
B-1
APPENDIX B – TYPICAL CONTENT IN A DATA COLLECTION RFP
The guide provides links to Requests for Proposals that were issued by the Tennessee and Utah
DOTs for building their roadway asset inventories using automated techniques. Since publishing
the RFPs in full is prohibitive, a summary of the key technical portions of a data collection RFP
is provided here.
In practice, the RFPs that were used in building this summary contained requirements for
collecting both roadway asset inventory information as well as pavement condition data for
pavement management surveys. Because of this, the RFPs may contain more detail than is
required if the contract had been issued only for the roadway asset inventory. However, agencies
realize the greatest benefits from the use of automated technology when multiple agency needs
are addressed, so this was not considered to be a major issue. Agencies are encouraged to
carefully consider their data collection goals and objectives, their data needs, and available
resources when using this information to develop an RFP.
The introductory sections of an RFP typically include the following.
Reason for issuing the RFP and the goals it is intended to accomplish.
Background information on the current state of the agency and its asset inventory.
Information about the procurement process and pre-bid meeting.
Intended length of the contract and the price guarantee period.
Regulations on partnering, joint ventures, use of sub-contractors and so on.
Terms and conditions relating to insurance, auditing, contract issuance and other agency
policies.
The technical specifications outlined in the body of the RFP typically includes the following
types of information.
General information on mileage, anticipated schedule, and other basic requirements.
Data collection specifics concerning data accuracy, routes to be included, route
numbering approach, and so on.
Division of responsibilities among the agency and the contractor, including a list of the
information and assistance that will be provided by the agency.
Specifics regarding the agency’s data collection requirements and guidelines.
Data processing specifics (if any) and data delivery format, including any requirements
for the vendor to provide data in a digital user format that can be accessed without
proprietary software.
Functionalities expected in the software and tools provided by the vendor.
Proposed training schedules for agency personnel to collect, process, and manage the data
using tools provided by the vendor.
Data storage and data hosting responsibilities.
Data ownership declarations.
A Guide to Collecting, Processing, and Managing Roadway Asset Inventory Data
B-2
Detailed quality control/quality assurance strategies and timelines for remedies.
Historic data integration strategy.
Incentives and disincentives based on quality, timeline, and deliverables.
Some of the common appendices or addendums included with an RFP are listed below.
Selection criteria.
Network maps.
Data dictionaries for assets to be included in the inventory.
Condition assessment manuals (if in the same RFP).
A sample contract with standard provisions that will be included.