Technologies to Support the Storage, Retrieval, and Use of 3-D Utility Location Data (2015)

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10 With the literature search complete, the next step was to develop the framework of policies, processes, procedures, and systems to store, retrieve, and use 3-D utility location data in highway renewal projects. This chapter outlines the following: • The approach and process used to develop the framework; • The key challenges that were identified; • The proposed framework and conceptual workflows; and • Data and administrative considerations. Approach and Process In developing the framework, the project team used a com- bination of best practices identified in the literature search, technologies and protocols under development by both the project team and other organizations, novel ideas from the project team, and commercially available hardware and software. This approach allowed the project team to select the best possible combination of protocols, models, and technologies. Workshop Development of the final strategy began with GTI, TRB, and Bentley Systems attending a workshop held in January 2013. The goal of the workshop was to discuss the requirements of a 3-D utility model for a DOT project area that could 1. Support the utility and project design; 2. Store 3-D as-built utility data at the completion of a DOT project; 3. Maintain an ongoing 3-D record of utility data as changes are applied over time; 4. Define a proof-of-concept project that could be used to test the 3-D Utility Data Model; and 5. Define a pilot implementation within a production environment. The workshop attendees agreed that one key element of a successful framework should be the integration of the 3-D Utility Data Model with existing business processes performed by DOTs. Every care should be taken to avoid creating a new database requirement that would require a new business pro- cess and therefore lead to higher production costs. The attendees spent time during the workshop discussing the legacy data that are typically associated with a highway construction project. Legacy data processing provides a wealth of data. The framework needs to address how these data could be used to assemble an initial 3-D project utility model. The attendees also discussed in significant detail the 3-D modeling requirements that they felt would aid in the design, construction, and recovery of utility infrastructure. This included a discussion on testing the effectiveness of distin- guishing data quality (defined by ASCE 38-02 as quality level A, B, C, or D). Key Challenges The following bullets present the key challenges that were identified during the workshop. • The project is intended to develop alternative strategies for acquiring 3-D utility location data and implementing a pilot project that includes a number of participating utilities within a defined geographic area. • The project will provide a demonstration of the access con- trol, data security, data source and quality level (based on the Standard Guideline for the Collection and Depiction of Existing Subsurface Utility Data, ASCE/CI 38-02), position- ing uncertainty, available characterization data, and liability issues that would be faced in a full-scale implementation of the system. • Ongoing database management issues, data ownership, and data sharing shall be discussed. Providing documented C h A P t e r 3 Solution Framework

11 examples of solutions to these administrative and legal issues is an important part of the project. • The project should include implementation of positional and structural data capture involving the participating agency and the participating utilities for new utility instal- lations and exposure of existing utilities, and the removal or updating of the status of those utilities that may have been relocated. • The project shall include the pilot implementation of com- puterized utility data, maps, and models. This implemen- tation will be used for locating and characterizing utilities for design purposes, as well as for damage prevention in excavation or construction projects. Existing laws and best practices regarding utility damage prevention should be followed. The advantages and disadvantages of the pro- posed approaches should be recorded. As a result of the workshop, a conceptual workflow was defined. This workflow included the following: • Registering legacy utility data (mostly from 2-D sources); • Creating an engineers’ repository; • Processing site data with traditional CAD and GIS tools; • Generating 3-D utility models from existing legacy con- tent; and • Storing all utility content in an open 3-D utility model based on Oracle Spatial (discussed in more detail in Chapter 4). Proposed Framework and Conceptual Workflow To provide context to support an understanding of the sys- tem architecture and administrative processes, the concep- tual workflow is described below. The workflow describes how data are initially captured for a project and moved through the subsequent processes of design and maintenance of the project area, continuing through to project closeout. Each process is intended to ensure that the system has a high level of data integrity and is kept current. The high-level workflow contains 14 key activities as listed below. Following the key activities list, graphical displays and summaries for four data input use cases are provided to add clarity and detail to these high-level workflow descriptions. 1. The DOT creates a project boundary definition (narra- tive) in the content management system and, most impor- tant, in the 3-D utility storage system. The project boundary is created in 2-D geometry but is still stored inside the 3-D utility storage system. The project bound- ary is created and stored as a polygon feature. 2. The DOT appoints a utility data analyst for the project who is responsible for all data and data changes in the system. This role is given the name Gatekeeper, which will be used throughout this document. 3. The DOT provides utility feature definitions and layering standards for 2-D and 3-D CAD data and ASCE 38 data quality level requirements to the person/organization responsible for developing a base condition record of util- ity infrastructure locations. This work of acquiring the field utility information is usually performed by a DOT contractor, such as an engineering company or subsur- face utility engineering (SUE) firm. Additional utility information may come directly from a utility or govern- ment agency responsible for utilities. 4. The base conditions of the project site can be captured through utility records, field surveys, and other data sources. Much of the data is submitted in electronic files in CAD or GIS formats. Additional data in the form of images (raster scans of paper documents), PDF files, and raw data from various scanning and locating technologies may also be submitted for reference purposes and saved in offline storage in the content management system. 5. Utility files of CAD data submitted from the engineering, SUE vendor, or subcontractors are submitted to the Gatekeeper for loading into the content management system. Background data such as utility records, draw- ings, photos, and other background information are also submitted to the Gatekeeper to be included in the con- tent management system as supporting information. 6. All underground utility work requires the issuance of a right-of-way (ROW) permit. The ROW permit must be obtained by the entities performing construction work before the start of a project. The boundary of the ROW permit defines the area of construction where the loca- tion and/or status of utility structures will be changed. During the permit application process, the DOT provides the utility company with specific documentation require- ments for design and as-built files. The utility company must acknowledge these requirements. Each permit must be monitored to ensure that the required submit- tals are delivered to the DOT consistent with permit requirements. 7. Permits to proceed with work should be issued contin- gent on the satisfactory submittal of designs consistent with permit documentation requirements. Permit appli- cations for new work may be accepted contingent on the utility company’s compliance with submitting as-built documentation on prior projects for which construction permits have been issued. 8. In those states where ROW permits are not directly con- trolled by the DOT, the DOT provides specifications for data submittal for incorporation into local or state permit- ting agency protocols. The specifications address spatial accuracy, data quality, and utility feature data definition.

12 9. As part of the as-built documentation process, smart tags (such as RFID ball markers) should be installed by the permittee/utility contractor during the construction process in accordance with the DOT’s applicable policies to facilitate the relocation of utilities in the future. 10. During the project and after its completion, the Gate- keeper retains all documents that record changes to underground utility locations. Each record should be linked to an ROW permit or other administrative change to document the polygon features. 11. Excavation and utility work occurring within the project boundary during the project or after its completion is identified through the permit process and the One-Call system. If suitable land-based features exist that can be easily identified on aerial photography, during or after the DOT project, digitizing the One-Call ticket bound- ary is a recommended means of establishing a One-Call ticket polygon. One-Call polygon boundaries provide a means of checking, validating, and ensuring that an ROW permit was issued and that the proper documenta- tion was submitted and approved. Permit application boundaries without proper approvals can create warning notifications to the DOT Gatekeeper, alerting him or her that the system is missing critical documentation to maintain proper control of changes to the underground utility features. Measures must be taken to ensure that no physical changes are made in the utility underground with- out the proper documentation. 12. The Gatekeeper monitors One-Call tickets submitted within the DOT project boundary to identify excavation work. If excavation activity is detected that does not have the appropriate ROW permit, the DOT can contact the excavation contractor and/or utility company to require submittal of the appropriate permit application. 13. Utility companies collect location data according to the DOT requirements on newly installed or relocated facilities. 14. The Gatekeeper reviews the data submitted by the utility company and enters them into the content management system. Once the changes are made, the ROW permit polygon’s status is updated to show that utility and other underground features have been updated in the content management system. With this status change the source documents are used to build the 3-D geometry in the CAD environment, and the model builder is used to build, extract, and insert the 3-D utility features into the 3-D utility storage system. Data Input Use Cases Highway right-of-way 3-D utility location data can originate from the DOT, a DOT contractor (or SUE firm), or a utility company. For the purposes of process modeling, two data input use cases for a DOT project have been developed and are described below. Base Conditions The input data contain the original utility data collected to start the design phase of the project. The scope of the base conditions should clearly identify any utilities that are omit- ted from the base condition (e.g., residential service lines or underground street light circuits). The steps involved in base conditions data capture are as follows (see Figure 3.1): 1. DOT creates project. 2. DOT creates project boundary polygon(s). 3. DOT requests data from all utility companies (check in to content manager). 4. DOT requests utility data from existing project area data stores (check in to content manager). 5. DOT requests all permits issued for work in the project boundary (check in to content manager). 6. DOT classifies all records received in Steps 3, 4, and 5 according to ASCE 38. 7. DOT Gatekeeper verifies data classifications and releases for 3-D conversion. 8. DOT creates 3-D models of utility systems inside the project boundary. 9. DOT develops a list of those areas where the ASCE 38 classification dictates more investigation. 10. DOT Gatekeeper receives utility data submittals from investigation processes defined in Step 9 above and loads them into the content manager as field investigation and data collection progress (3-D data are loaded directly into 3-D storage, 2-D data are converted to 3-D and uploaded to 3-D storage system). 11. Design may proceed in areas not designated as under investigation in Step 9. Non-Project-Related Changes For this use case, data are submitted by the utility company for any work that results in a change in status or location of utility lines within the project boundary but is not directly related to the DOT project. The steps involved in non-project-related changes in data capture are as follows (see Figure 3.2): 1. DOT receives ROW permit request from utility company (permit pending). 2. DOT issues permit and data requirements to utility com- pany (data accuracy, ASCE 38) (permit issued). (text continues on page 15)

13 Figure 3.1. Initial system data load workflow. SUE Contractor(s) (Step 5) DOT Utility Analyst Define New Project Area (Step 1) Develop Project boundary (Step 2) Relocation Requirements in Project Area Utility Feature Requirements 3-D 2-D Geometry (National coordinate system) Feature Attributes (if known) Spatial accuracy (if known) Data Accuracy (if known) Meeting Participants: SUE, Utilities Delivery of the required utility inventory solicited (Step 3) Project boundary map Utility submit Directly to DOT (Step 4) Submit Electronic Drawings and Documents Gas, Sewer Telecom, Electric, Potable Water Submit Electronic Drawings and Documents Gas, Sewer Telecom, Electric, Potable Water Utility Feature Requirements 3-D 2-D Geometry National coordinate system Feature Attributes ASCE Classification A-D Utilities DOT Utility Data Analyst Data Review ASCE 38 Classification State Specific DOT Stds (step 6) DOT GATEKEEPER Approval Feature Load CAD File Check in 3D Utility CAD Models Spatial Data 2D Utility CAD Raster documents Survey records Other utility documents 3-D Utility StorageInitial System Data Load Work Flow Spatial Database ServerContent Management Server Returned for Update ASCE 38 Classification C-D (Step 7) Model Builder Model Builder 3-D/2-D Utility CAD Models CAD Design WS CAD Design WS

14 Figure 3.2. Utility data change control processing. SUE Contractor(s) DOT survey Utility Subcontractor Submit Electronic CAD/GIS Drawings and Documents Gas, Sewer Telecom, Electric, Potable Water Utility Feature Requirements 3-D Geometry Utility feature attributes National coordinate system Data Accuracy (ASCE Classification A-D) DOT Gatekeeper Data Review/Approval ASCE 38 classification State Specific DOT Stds Criteria .. DOT Utility Data Analyst Update project utility features Load content manager Update 3-D utility model CAD File Check in Returned for correction / update Utility submit Directly to DOT Submit Electronic Drawings and Documents Gas, Sewer Telecom, Electric, Potable Water Utilities DOT Utility Data Analyst Change Control Processing Review DOT permits Correlate one call notifications with DOT Permits Update status on utilities in question in project areas 3D Model Manage as-built data request document flow Message Utilities for As-built drawings for changes from open permits Allow issue of permits based on updated documentation (previously opened permits) Request as-built documents Manage permits Utility Data Change Control Processing (Continuous) 3-D Utility Storage Spatial Database Server Content Management Server Model Builder Source Documents 2-D CAD, Raster, PDF 3-D Utility Models permits 3D Utility CAD Models permits Returned for correction / update

15 3. Utility company submits a One-Call ticket request. 4. The system determines if the excavation area defined by the One-Call ticket is within the boundary of a DOT proj- ect. If overlap occurs, the system supervisory applications verify submittal status on an ROW permit and issue a sta- tus message to the DOT Gatekeeper if the One-Call ticket is in an area without an ROW permit. 5. If there is an ROW permit, the system changes the status on the ROW permit when the One-Call mark-out order is issued (construction). The content manager defaults to a second status (waiting for as-built). 6. Utility owner relocates facility and collects and transmits as-built data according to ROW permit instructions. 7. Gatekeeper reviews as-built information, checks the infor- mation in to the content manager, and updates the ROW permit status. Then, the system automatically sets a third status on the ROW permit as 3-D updates pending or built per design. 8. Engineering updates the 3-D model per as-built docu- ments and sets final permit status (permit closed). 9. Gatekeeper verifies changes to the system. Data and Administrative Issues A number of data and administrative issues need to be con- sidered and addressed when the 3-D utility model is initially developed and as it is maintained for long-term use. Data Collection The framework is based on the premise that the DOT creates an initial 3-D utility model by loading source data, utility spa- tial files, utility design files, reports, sketches, and raster rep- resentations of utility locations into the content manager for conversion. There is no assumption that the data are com- plete or reliable. Instead the available data are loaded into the content manager and characterized by quality levels. The intent is to create a mosaic of utility features that can be updated and refined over time. Certain utilities may not be captured at all during creation of a project’s base map. These might include street lighting, signage, traffic control loops, and residential services. As such, it is critical that the initial project defini- tion contain metadata that clearly indicate any utility information that is unconfirmed or missing from the initial 3-D model. The base utility map will likely be composed of both 2-D and 3-D representations of underground utilities with the appropriate ASCE 38 quality level. By loading the data in all of their various states of quality, a baseline is set that allows the DOT to focus its efforts on verification of incomplete data or data of unknown quality. This eliminates the expenditure of funds for validating data that are known to be accurate. The process of developing this mosaic of different quality level data also allows for the development of work plans targeted at updat- ing the most important data. All utility data must be classified according to ASCE 38 when loaded into the content manage- ment system. Data received that are not classified according to ASCE 38 will be classified as unknown quality. All data that are loaded in this manner shall be characterized through notation of the means and basis under which they were collected. This characterization will be recorded in a note field accompanying the data as they are filed in the content management system. In the event that the information has no geographic location data, the document will initially be associated with an area defined by the DOT project boundary. A primary objective is to create utility features that are reli- able for design purposes from the various base map data sources. This process is critical so that all of the data loaded at the beginning of the project can be used to determine which data are in need of updating and further field investi- gation. The overall goal is to provide as much high-quality data to designers at the beginning of the project as possible to reduce the amount of new data that must be collected. Utilities with underground facilities whose location stays constant but undergoes a status change should provide an update of this information to the DOT. Abandoned facilities are a good example of such a requirement covered under this condition. Field Data Collection When new underground construction is performed through an open trench, the permitting processes should mandate col- lection of both horizontal and vertical utility data. Utility locations should not be reported relative to local landmarks but should be recorded based on a national coordinate system. Spot checks of horizontal and vertical utility locations in the field through excavation, as well as surface geophysical tech- niques, should be used to upgrade quality level classifications in accordance with ASCE 38-02 Standard Guideline for the Collection and Depiction of Existing Subsurface Utility Data. Utilities that are directionally drilled have the same quality level requirements. During drilling operations, the drill head should be tracked with aboveground locating equipment. Many locating and data capture technologies for utilities can produce vast quantities of raw data that have limited direct value for permanent storage. If the raw data are deemed important and the file size is reasonable, the data can be stored in the content management system. If the data set is very large, such as the data resulting from any laser scanning technolo- gies, it is recommended that the data be housed in an offline storage system. References to the location of this storage should be catalogued in the system for future use. Online stor- age of raw data cannot be accommodated in the 3-D model.

16 The installation of smart tag markers on newly constructed utilities should be seriously considered for all future installa- tions. For example, VDOT requires that RFID ball markers be installed at a frequency ranging from 25 feet to 50 feet, depend- ing on the level of congestion, along utility lines as they are exposed. Additionally, smart tag markers should be installed in any excavation, such as test holes, performed during the initial data validation and design phase. The location and identification of the markers can be added to the utility spa- tial database as RFID locating features. These markers will provide an enhanced utility location verification tool during the design and construction phase of future projects. The markers provide a quick way to verify existing utility features without excavation and can reduce the occurrence of excava- tion damage and its consequences. GTI has developed a GPS-based technology in other research projects that can be used to record the locations of utility fea- tures with high levels of spatial accuracy and precision. This technology could be deployed during a DOT construction proj- ect, providing a means of recording new utility installations and updating and/or correcting existing utility locations in real time. The system is unique in that it allows for the precise updating of utility features that are housed in a geospatial envi- ronment without any back-office processing. Data Quality and Accuracy Standards Implementing quality and accuracy standards is an impor- tant part of ensuring the integrity and reliability of the sys- tem. The DOT provides data accuracy and quality level requirements for each project. The DOT may specify differ- ent accuracy and quality level requirements for different util- ity types. For example, the DOT may require a higher level of accuracy for positional data of critical utilities, such as trans- mission facilities and communications cables that are dedi- cated to vital services. ASCE 38 should be used as the data quality standard. It is worth noting that ASCE 38 is not an accuracy standard but is instead an accountability standard that requires a pro- fessional’s seal. This seal indicates that all data were collected under the responsible charge of that professional and that judgment was then used to assign a quality level—A, B, C, or D. There is no universal agreement or compliance with these standards in the industry to date, and the definitions are sub- ject to change. It is therefore important to store the date, method of collection, and other information recorded in the field related to data quality. One requirement of the system is that it facilitate the view- ing of data by quality levels. Quality level designation enables designers to distinguish between different accuracies and dif- ferences between horizontal and vertical measurements. This applies to 2-D and 3-D representations of the data. All utility location data that are loaded into the 3-D utility model must be consistent with the project datum and coor- dinate system. Data that are received with a different datum and coordinate system must be converted before incorpora- tion into the 3-D utility storage system. If the data are sub- mitted by an outside agency and are not consistent with the datum and project coordinate system, the data must be sub- mitted with metadata clearly defining the datum and coordi- nate system used. Information must be recorded in the metadata of any spatial data using NSDI FGDC-STD-001 CSDGM. If the data are in CAD format, the datum and coor- dinate system must be incorporated into the attribute data describing the files that are included in the content manage- ment system. Data created specifically for the project (engi- neering designs) must be consistent with the datum and coordinate systems specified by the DOT. Quality Assurance and Quality Control For purposes of this project, quality assurance is defined as the oversight of processes and organizations responsible for implementing and maintaining proper quality control of the data, the systems used to process the data, and organizations that create data. Quality control processes are used to ensure that the required standards and specifications are met in the creation and collection of data required for a project. It is recommended that sampling plans consistent with NSDI FGDC-STD-007.3 be implemented to measure and quantify data accuracy. This sampling process, which produces utility location data certified to a quality standard, is a primary qual- ity control function. Data delivered to the DOT for the intended use of upgrading the quality levels of a set of utility features stored in the system must meet the certification requirement of ASCE 38. It is recognized that some data may be loaded into the sys- tem that has not been certified to ASCE 38. When data that are not certified to ASCE 38 are loaded into the system, this condi- tion must be noted. The system should have a status defining no ASCE 38 classification. Data loaded into the system in this condition serve as a starting point for additional field investi- gation work. According to SUE practices, data quality validation and cer- tification are accomplished by sign-off on all work submitted to the DOT by a registered professional engineer. Production projects should use this practice as much as possible by having an approval step before any utility data are loaded into the content management system or the 3-D storage. The Gate- keeper will look for evidence that the data are certified to a given quality level by a registered professional. Source docu- ments such as CAD models, images of paper drawings, and any other electronic documents added to the content manage- ment system should be classified with the appropriate quality

17 level noted on the metadata associated with each record filed in the system. In the context of the SHRP 2 R01A project, quality control tasks are performed before the data are entered into the sys- tem. The project team envisions that these policies will be established by the users of and contributors to the system. A critical requirement of any system used to track change is a process to ensure and maintain data quality. Unknown, poor, or incomplete data can result in a system with limited value. The Gatekeeper is responsible for monitoring and approv- ing all data flows into the system. Responsibility for all data flows into the system does not necessarily suggest that data cannot be loaded by multiple individuals or organizations, but it does suggest that versioning and revision control of data is the sole responsibility of the Gatekeeper. Specifically, the Gatekeeper is responsible for identifying suspect data, selecting the more accurate and reliable data when conflicting data are submitted, promoting and demoting data, request- ing additional or more reliable data, adding missing data, and assuring quality designation of submitted data. Data collected by any means are candidates for inclusion into the system. The Gatekeeper reviews all data, including the metadata. When the accuracy of the data being submitted is unknown, this condition is noted in the metadata, and the data quality grading is adjusted accordingly. The Gatekeeper has the authority to incorporate data sub- mitted from other stakeholders into the permanent record after the appropriate review. The Gatekeeper is responsible for ensuring the most current information is available in the system, reflecting the best-known underground utility infor- mation for the project area. Updates to the 3-D storage are the responsibility of the DOT engineering and design depart- ments; the Gatekeeper primarily serves a control and audit function. The Gatekeeper is responsible for system monitoring to ensure that the change control features (permits) status is accurate and that the underlying documentation reflecting changes in the project area is consistent with the changes that have taken place in the field. At a minimum, if there are changes in the project area, the Gatekeeper is responsible for ensuring the system reflects changes even if the system lacks details of the changes. This will be a common condition since human interaction with the system is part of the process flow. The system is designed to define the areas where change has taken place so that the underground exploration and defini- tion activities can be focused on areas requiring more detail. Security and Access Controls Since this system is operated primarily for the management of the DOT right-of-way, the security and access controls should be managed by each state DOT. All modifications and addi- tions of data should be within the strict control of the DOT and follow internal security and access control protocols. Util- ities would benefit from read access to the data, but read access should be limited geospatially to an area of limited size. Orga- nizations that issue permits should also be granted read access to the 3-D utility store and write access so they can spatially define the limits of the permit areas. The Gatekeeper should be the only person authorized to provide access to files or spa- tial data for modification within the system. Access to the data should only be granted to authenticated users who are defined by roles whose definitions are con- trolled by the Gatekeeper. Given the sensitive nature of some of the data, background checks might be considered before granting access to the data. Permitting The ROW permit process is the mechanism used to commu- nicate and ensure compliance regarding data submittal requirements. At a minimum, the submission of data during the permit application must address both horizontal and ver- tical locations of any modifications of utility infrastructure within the project boundary. The permit must include lan- guage requiring drawings that reflect as-built conditions for each permit issued, showing where the utility facilities are moved or created in the project area. Additionally, the system must register and track the location and status of each permit by the requesting utility and track the identity of the permit requestor. This tracking is needed to ensure that on subse- quent permit requests the person or agency requesting a new permit has no outstanding permits for which the required as-built drawings have not been submitted.