J.3_FHWA_RESEARCH_AHC-Vol-II-Final_Draft.pdf

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FOREWORD

The Federal Highway Administration (FHWA) conducted research to document gaps for implementing Automation in Highway Construction and to develop guidance for state transportation departments to assist them in implementing and using automation to improve project delivery. There are two volumes of the final report for each of the two objectives. Part I of the final report presents a description of the key automation technology areas and the associated benefits, challenges, and solutions. Part II of the final report (this volume) presents an overview of enabling technologies and policies for automation in highway construction, along with implementation strategies, design procedures and practical guidelines to properly generate

3D models for uses in construction and other phases of highway project delivery.

Developing 3D digital design data for use in automation in highway construction requires tighter accuracies on both survey control and topographic survey. 3D design practices are well entrenched in state transportation departments, but automation technology requires added detail in 3D design models and additional effort to output data in a portable and durable format, organize, and describe that data. Construction specifications need to be performance-based incorporating practices to manage the use of automation technology in a flexible manner to adapt to conducive project characteristics and evolving technologies. There is a growing desire to use

3D models as construction contract documents. Consistency in 3D data and survey methods employed by the contractor and inspector is important to isolate tolerance and measurement differences. Use of 3D data to automate inspection tasks, especially acceptance and measurement processes, can enhance transparency, make inspectors available to observe construction, and enhance safety. The training needs for implementing automation in highway construction are vast, and especially disruptive for inspectors.

Jorge E. Pagán-Ortiz

Director, Office of Infrastructure

Research and Development

Notice

This document is disseminated under the sponsorship of the U.S. Department of Transportation in the interest of information exchange. The U.S. Government assumes no liability for the use of the information contained in this document.

The U.S. Government does not endorse products or manufacturers. Trademarks or manufacturers’ names appear in this report only because they are considered essential to the objective of the document.

Quality Assurance Statement

The Federal Highway Administration (FHWA) provides high-quality information to serve

Government, industry, and the public in a manner that promotes public understanding. Standards and policies are used to ensure and maximize the quality, objectivity, utility, and integrity of its information. FHWA periodically reviews quality issues and adjusts its programs and processes to ensure continuous quality improvement.

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1. Report No.

FHWA-XX-NN-NN

2. Government Accession No.

N/A

3 Recipient Catalog No.

N/A

4. Title and Subtitle

AUTOMATION IN HIGHWAY CONSTRUCTION:

Final Report - Part II

A Design Guidance and Guide Specification Manual

5. Report Date

July 2015

6. Performing Organization Code

N/A

7. Author(s)

Francesca Maier and Dr. Jagannath Mallela of Parsons Brinckerhoff

Helga N. Torres, J. Mauricio Ruiz, and Dr. George K. Chang of Transtec Group

8. Performing Organization Report No.

N/A

9. Performing Organization Name and Address

Parsons Brinckerhoff The Transtec Group, Inc.

100 S. Charles Street 6111 Balcones Drive

Baltimore, MD 21201 Austin, TX 78731

10. Work Unit No. (TRAIS)

N/A

11. Contract or Grant No.

DTFH61-13-C-00026

12. Sponsoring Agency Name and Address

USDOT-Federal Highway Administration

Office of Infrastructure R&T

Infrastructure Analysis and Construction Team

6300 Georgetown Pike, HRDI-20

McLean, VA 22101

13. Type of Report and Period Covered

Draft Final Report

14. Sponsoring Agency Code

N/A

15. Supplementary Notes

Contracting Officer’s Representative: Richard Duval

16. Abstract

Automation in Highway Construction includes an increasing number of technologies that collect, store, analyze, and process information to make, support or execute an appropriate action or decision that results in enhanced construction outcomes. The goals of automation in highway construction are to increase the speed, efficiency, and/or safety during the construction process. This is in conjunction with components, processes, and software that assist in a more efficient system of construction.

The primary objectives of this project are to address gaps identified for implementing automation in highway construction and to develop guidance for state transportation departments to assist them in implementing automation to improve accelerated project delivery. There are two volumes of the final report for each of the two objectives.

Part I of the final report presents a description of the key automation technology areas and the associated benefits, challenges, and solutions.

Part II of the final report (this volume) presents an overview of enabling technologies and policies for automation in highway construction, along with implementation strategies. The Part II report also includes design procedures and practical guidelines to properly generate 3D models for uses in construction and other phases of highway project delivery.

17. Key words

Automation in highway construction, intelligent construction, automation, guidelines, guide specifications

18. Distribution Statement

No restrictions.

19. Security Classif. (of this report)

Unclassified

20. Security Classif. (of this page)

21. No. of Pages

19. Security Classif.

(of this report) iv

Contents

ACKNOWLEDGMENTS

DISCLAIMER

1. INTRODUCTION

1.1 OBJECTIVE

1.2 SCOPE

1.2 GLOSSARY OF TERMS

2. DEVELOPMENT OF AUTOMATION TECHNOLOGY GUIDELINES

2.1 OBJECTIVES

2.2 STAKEHOLDERS

2.3 POLICY AREAS

2.4 CAPITAL AND HUMAN RESOURCES INVESTMENTS

2.4.1 Hardware

2.4.2 Software

2.4.3 Changing Job Functions

2.4.4 Training Needs

3. IMPLEMENTATION STRATEGIES

3.1 FORMAL IMPLEMENTATION PLANS

3.2 NOTABLE IMPLEMENTATION STRATEGIES

3.2.1 Establishing a Vision

3.2.2 Defining a Purpose and Need

3.2.3 Identifying Known Issues

3.2.4 Implementation Goals

3.2.5 Establishing an Implementation Team

3.2.6 Specific Activities

3.2.7 Tracking Performance

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3.3 IMPLEMENTATION PLANNING RESOURCES

4. ENABLING TECHNOLOGIES AND POLICIES

4.1 IN PLACE CAPABILITIES

4.2 CAPABILITIES REQUIRING DEVELOPMENT

4.2.1 Survey

4.2.2 Subsurface Utility Engineering

4.2.3 Design

4.2.4 Bidding

4.2.5 Construction

4.3 IMPLEMENTATION MATURITY

5. INTRODUCTION TO AUTOMATION TECHNOLOGY APPLICATIONS AND

GUIDELINES

6. SURVEYING

6.1 ESTABLISHING SITE CONTROL

6.1.1 Control Accuracy

6.1.2 Situating Control

6.2 METADATA

6.3 ACCURACY TOLERANCES FOR TOPOGRAPHIC SURVEY

6.4 USE OF REMOTE SENSING

6.5 NON-TRADITIONAL SURVEY PRODUCTS

7. SUBSURFACE UTILITY LOCATION

7.1 PURPOSE OF SUBSURFACE UTILITY ENGINEERING

7.2 DATA QUALITY LEVELS AND APPLICATIONS

7.3 DATA QUALITY LEVELS AND APPLICATIONS IN PROJECT DELIVERY

7.4 USING 3D SUBSURFACE UTILITY LOCATION INFORMATION

8. DESIGN

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8.1 APPLICATIONS IN DESIGN DEVELOPMENT

8.2 CONSIDERATIONS FOR STANDARD DETAILS

8.3 CADD DATA TYPES AND 3D MODELING APPROACHES

8.4 GUIDE 3D MODEL STANDARD

8.4.1 3D Model Content

8.4.2 3D Model Density

8.4.3 3D Model Segmentation

8.5 GUIDE 4D AND 5D MODEL SPECIFICATION

8.5.1 4D and 5D Model Usage Cases

8.5.2 4D and 5D Model Target Audiences

8.5.3 Steps in Creating 4D and 5D Models

8.5.4 Viewing 4D and 5D Models

8.6 GUIDE 3D DATA REVIEW PROTOCOLS

8.7 CONTRACT DOCUMENTS

8.7.1 Contract Plans

8.7.1 Contract 3D Models

9. GUIDE SPECIFICATIONS

9.1 CONTROLLING WORK: PLANS AND WORKING DRAWINGS

9.1.1 Contract Documents

9.1.2 Hold Harmless Statements

9.1.3 4D and/or 5D Models

9.1.4 3D As-built records

9.2 CONTROLLING WORK: CONFORMANCE WITH PLANS AND

SPECIFICATIONS

9.3 CONTROLLING WORK: CONSTRUCTION STAKES, LINES AND GRADES .. 107

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9.4 CONTROLLING WORK: INSPECTION OF WORK

9.5 CONTROLLING WORK: QUALITY CONTROL PLAN

9.6 MEASUREMENT AND PAYMENT

9.7 EARTHWORK, FINE GRADING, BASE COURSE AND PAVING

10. CONSTRUCTION

10.1 CONSTRUCTION DATA MANAGEMENT

10.1.1 Establishing a Model of Record

10.1.2 Managing Design and Field Changes

10.1.3 Digital As-built Records

10.2 LOW ACCURACY POSITIONING

10.3 HIGH ACCURACY POSITIONING

10.4 AGREEING CONTROL AND SITE LOCALIZATION OR MAPPING

PROJECTION

10.4.1 Source of RTK Correction for GNSS

10.4.2 Base Station Set-up

10.5 AUTOMATION FOR CONSTRUCTION ENGINEERING AND INSPECTION ... 123

10.5.1 Use of As-Built Data for Measurement and Acceptance

10.5.2 Capturing As-Built Data with Field Survey

10.5.3 Capturing As-Built Data with Remote Sensing

10.5.4 Limitations of Real-time Observations

11. AUTOMATION TECHNOLOGY INTEGRATION

12. CONCLUSIONS

13. REFERENCES

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Tables Table 1: Stakeholders in Automation in Highway Construction implementation

Table 2: Recommended modifications to manuals

Table 3. Sample Resource Assignment Matrix

Table 4. Initiative Planning Worksheet (Maier, et al., 2013)

Table 5. Capability/maturity matrix for enabling infrastructure (Maier, et al., 2013)

Table 6. Capability/maturity matrix for applications of Automation in Highway Construction

(Maier, et al., 2013)

Table 7. Minimum positional accuracies for mapping control to support Automation Technology.

Table 8. Sample Survey Metadata

Table 9. Minimum network accuracies for different feature types

Table 10. Survey Resolution Required to Support AMG Operations

Table 11. Suitability of LiDAR methods by topographic mapping accuracy ranges

Table 12. LiDAR method suitability for different project characteristics

Table 13. Project characteristics favorable for different LiDAR methods

Table 14. Locating technologies and resulting data for different quality levels

Table 15. Applications of 3D models during design development (Maier, et al., 2013)

Table 16. CADD design methods and their uses

Table 17. 3D Model content by CADD data type

Table 18. 3D Model content by project type and applicable AMG methods

Table 19. 3D Model content by design milestone

Table 20. 3D Model density by design milestone

Table 21: Usage cases for 4D and 5D models

Table 22: Target Audiences for 4D and 5D models

Table 23. Examples of visual inspection strategies

Table 24. Notable practices for creating contract plans

Table 25. Type, format and metadata for bid reference files

Table 26. Areas of Standard Specifications affected by automation implementation in highway construction

Table 27. Requirements for as-built data by intended use of data ix

Table 28. Data types that can constitute the Model of Record

Table 29. Pertinent information for a Contract Control Plan (New York State, 2014)

Table 30. Inspector Tool Selection Guide

Table 31. Use of Field Surveying Tools to Measure Quantities x

Figures

Figure 1. Integration of Automation Technology on the Southeast Freeways Project (Parve, 2012)

Figure 2. A workflow for developing automation technology guidelines

Figure 3. Implementation Process

Figure 4. A workflow for increasing capacity with enabling technologies and policies

Figure 5. Planning for automation technology integration begins at project inception

Figure 6. Workflow for producing survey products to support automation in highway construction

Figure 7. Workflow for setting site control to support automation in highway construction

Figure 8. Effective control siting to support site localization for a linear project

Figure 9: Relationship between survey observations and elevations computed for a DTM

Figure 10. Unfiltered point cloud

Figure 11. Workflow for selecting subsurface utility locating techniques

Figure 12. Workflow to integrate 3D utility data into 3D Model or project plans (adapted from

SHRP2 R01)

Figure 13. Workflow for updating design policy documents to produce 3D data for Automation in Highway Construction

Figure 14. Workflow for using 3D models in design development

Figure 15. A CADD template representing a two-lane road with shoulders

Figure 16. A string model that uses rules to offset the baseline horizontally and vertically

Figure 17. Workflow for creating a standard 3D model specification

Figure 18. Approximation of curved objects in DTMs and 3D line strings

Figure 19. The mid-ordinate distance is the distance between a chord and the true arc

Figure 20. Workflow for developing a 4D/5D modeling plan

Figure 21: An example of a 3D still image from a 4D model for a technical audience

Figure 22: An example of a construction sequence viewed in the 4D modeling software

Figure 23. Workflow for producing contract documents and models

Figure 24. Workflow for providing contract models (Oregon Department of Transportation, 2012) xi

Figure 25. Workflow for developing Construction Specifications that support automation

Figure 26. Workflow for managing construction with automation technology

Figure 27. Workflow for establishing a Model of Record

Figure 28. Workflow for managing field or design changes in Model of Record

Figure 29. Workflow for preparing digital as-built records

Figure 30. Screen shot of an alignment preloaded in a mobile device

Figure 31. Workflow for establishing a plan for high-accuracy positioning

Figure 32: High accuracy AMG operations require very high accuracy vertical control

Figure 33: The site localization resides in the data collector and requires 5 control points

Figure 34: Workflow for using real-time verification in construction inspection

Figure 35: With a robotic total station any paving issues can be identified in real-time

Figure 36: Static LiDAR can be used to collect as-built data

ACKNOWLEDGMENTS

This project is possible due to the funding from FHWA and the assistance from state transportation departments leading efforts to implement Automation in Highway Construction.

The contribution of FHWA staff and other individuals is also acknowledged. A partial list is presented below.

Alexa Mitchell, Missouri DOT

Brad Hollister, Wisconsin DOT

Brett Dean, New York State DOT

Brian Smith, Iowa DOT

Bruce Dana, Florida DOT

Bruce Flora, Flora Surveying Associates

Cathy Cassar, Michigan DOT

R. David Unkefer, FHWA

Della Mosier, Oregon DOT

Douglas Townes, FHWA

John Lobbestael, Michigan DOT

Kathryn Weisner, FHWA

Lance Brown, Kiewit

Lance Greer, W.W. Clyde & Co.

Lance Parve, Wisconsin DOT

Laura E. Chummers, Parsons Brinckerhoff

Michael Kennerly, Iowa DOT

Nelson Aguilar, Caltrans

Rachelle VanDeventer, Michigan DOT

Ryan Forrestel, Cold Spring Construction

Stacy Kubit, Parsons Brinckerhoff

DISCLAIMER

This report represents the results of research conducted by the authors and does not necessarily represent the views or policies of the State transportation departments whose policies and practices have been referenced.

1. INTRODUCTION

While no state transportation department has fully implemented an integrated automation technology solution programmatically, there are several examples of very mature project-level implementations from around the United States that form the backdrop for the guidance developed in this report. In this report, there was not an attempt to capture a nationwide perspective but rather a collection of noteworthy practices being gleaned as part of a number of

“in motion” parallel efforts including the Federal Highway Administration’s Every Day Counts

(EDC) technology deployment outreach, the American Association of State Highway and

Transportation Officials (AASHTO) Domestic Scan program, and the National Cooperative

Highway Research Program (NCHRP) research, and state and regional conferences. Documented sources of notable practice were sought to provide illustrative guidance and guide specifications including survey, design and CADD manuals, construction specifications, special provisions and special notes, construction manuals, training materials, conference proceedings, and implementation documents.

At the project level, there are examples of an integrated approach to leverage a shared 3D digital dataset for automating a range of highway construction applications like Automated Machine

Guidance (AMG), construction layout and real-time field verification to accept completed work.

These projects shared the cost of creating and maintaining the necessary data while realizing the full benefit of each individual automation application. Figure 1, adapted from the Wisconsin

DOT Southeast Freeways project (Parve, 2012), serves as a good example to illustrate how automation can be integrated into the various phases of the project for more efficient delivery.

The vision for automation in highway construction is that the necessary 3D engineered data can be shared amongst and across a multitude of automation technology uses that are applicable to each project. These automation technologies may include remote sensing survey techniques such as Light Detection and Ranging (LiDAR), unmanned aerial vehicles (UAV), 3D model-based design, 4D and 5D construction simulation, subsurface utility location technologies, Automated

Machine Guidance (AMG) construction, electronic construction documents accessed via mobile devices (a part of e-Construction), and non-destructive methods for measuring and accepting construction (e.g., including ground penetrating radar, paver-mounted thermal profiler, intelligent compaction and real-time field verification with location-aware survey instruments).

Figure 1. Integration of Automation Technology on the Southeast Freeways Project (Parve, 2012).

1.1 OBJECTIVE

The objective of this project is to address challenges and opportunities identified for automation in highway construction from project development through construction and develop guidance for state transportation departments to assist them in determining how best to use automation to improve effective and accelerated project delivery. Some automation applications may warrant programmatic implementation, while others may warrant use on a project-by-project basis. The study involved collecting, organizing and analyzing data from various state transportation departments and other facility owners using automation technology.

Part I of this study relayed implementation and success stories from transportation agencies on the use of automation. The main goal of this document, Part II, is to provide design guidance and accompanying guide specifications for highway agencies to successfully implement automation in highway construction. The guidance covers how to generate 3D digital design data for downstream uses in construction, while the guide specifications provide information on how to manage the use of these data in construction.

1.2 SCOPE

The scope of this report does not imply a positive return on investment for implementing automation technology on all projects regardless of type, size and range of construction activities. Further research is being conducted into making value judgements on where automation in highway construction is beneficial. This guidance is intended to be used after the decision to implement automation technology has been made. The scope is built on the premise that to be able to optimally use automation during the construction phase of a highway project, preparation begins during the planning, surveying, and design phases.

Chapter 2 describes the objectives and stakeholders involved in an implementation, as well as affected policy areas, impacts on capital and human resources and change instruments for implementing automation technology. There are a number of investments in enabling technologies and policies that a state transportation department needs to implement to reap the benefits of a coordinated approach to automation in highway construction. These are covered in

Chapter 3. Implementation strategies used by agencies that have implemented mature (though not necessarily comprehensive) automation practices are contained in Chapter 4. Chapter 5 introduces the guidelines that follow in Chapters 6 through 10.

Chapter 6 describes the needs for capturing survey data prior to design. Chapter 7 introduces practices subsurface utility locating. Design development to support the uses of 3D engineered data, including 4D and 5D models, is described in Chapter 8. Guide specifications are discussed in Chapter 9. The guidance concludes in Chapter 10 with the use of 3D engineered data in construction by both the contractor and the owner. Chapter 11 discusses current successful automation technology integration and introduces future trends that should be planned for.

Chapter 12 provides conclusions and Chapter 13 lists the references and cited works.

1.2 GLOSSARY OF TERMS

A glossary of terms is provided to aid in understanding the terms used in the following sections.

Some of these terms were defined in Part I of this research report.

3D Engineered Model A 3D model of a roadway or related feature that is developed to the appropriate engineering precision to support construction applications.

3D Solid Primitives Solid 3D CAD objects that do not have any intelligence. They are based on regular 3D geometric shapes like cylinders and cubes. 3D

Solid Primitives may be mathematically extracted from Point Clouds to represent pipes, bridge piers, bridge girders, utility poles, etc. in CAD objects that are easier to manipulate for clash detection or visualization.

4D Model A simulation of how a facility changes over time, usually during construction. A 4D model is the product of connecting a 3D model to a schedule, introducing the 4 th dimension of time.

5D Model A simulation of how a facility changes over time where the related costs of those changes are included in the simulation. Usually, the changes involve construction and the costs are incorporated in the schedule. The 5 th dimension represents cost.

Absolute Accuracy Also called Network Accuracy. The level of accuracy in relation to a global coordinate system. In simple terms, the accuracy with which something can be located in the world.

AMG Automated Machine Guidance. Use of survey-grade position sensors and on-board computers to guide the operator or control the hydraulics of construction equipment.

Classification The process by which software sorts LiDAR data points into categories based on predefined rules. Predefined categories include ground, vegetation, noise, and water.

Corridor Model A method of modeling linear designs in CADD. The corridor combines horizontal and vertical alignments, superelevation definitions and a parametric cross-section definition with a DTM surface to create a 3D approximation of the design concept. The corridor model can output

DTMs of proposed surfaces like subgrade for use in AMG.

CORS Continuously Operating Reference Stations. Continuously operating

GNSS receivers in a fixed location that compute and broadcast a position correction for use in RTK GNSS applications.

DTM Digital Terrain Model. A digital topographic model of specific area of a ground surface minus objects such as trees, vegetation and structures that can be manipulated through computer aided design programs. All elements of the DTM are spatially related to one another in three dimensions represented as a network of triangular or polygonal faces.

DTMs for design and construction commonly use a triangulated irregular network (TIN).

Geospatial Data 2D or 3D data that is spatially referenced by being projected onto a mapping coordinate system such as a State Plane Coordinate System.

GNSS Global Navigation Satellite System. A system of navigation that uses a global network of satellites to provide autonomous geospatial positioning. The network of satellites includes the United States’ GPS system, Russia’s GLONASS, and will include China’s BeiDou and

Europe’s Galileo.

GPS Global Positioning System. A subset of GNSS comprising the satellites owned by the United States. Often used colloquially to refer to GNSS as a whole.

LandXML A data exchange format based on XML (extensive markup language) for horizontal construction data that provides support for surface, alignment, cross-section, pipe network, and point data types.

LiDAR Light Detection And Ranging. A remote sensing survey method. A sensor sends a pulse of light and measures the returning beam to define the position of the remote object that reflected the beam of light. The

LiDAR sensor may be mounted on a tripod (static LiDAR), mounted on a vehicle and in-motion (mobile LiDAR) or mounted on an aerial vehicle such as an airplane or helicopter (aerial LiDAR).

Local Accuracy Also called Relative Accuracy. The accuracy of the position of a point in relation to other points in the dataset. Local accuracy may exceed

Absolute (or Network) accuracy for a particular dataset. Local accuracy is a consideration for measuring depths, lengths or areas, which are unrelated to the geospatial location of the features.

Metadata A description of the basis of the data, typically survey data but may relate to any 3D data. Metadata usually includes the definition of the horizontal and vertical datums that relate 3D coordinate data to a physical location on the surface of the earth.

NSRS National Spatial Reference System. A consistent coordinate system used throughout the United States. The NSRS defines latitude, longitude, height, scale, gravity, and orientation.

Network Accuracy Also called Absolute Accuracy. The level of accuracy in relation to a global coordinate system. In simple terms, the accuracy with which something can be located in the world.

Point Cloud A collection of data points, often collected with remote sensing methods like LiDAR, which is so dense as to define the whole scene.

Point clouds often contain hundreds of thousands of points and may have a point density greater than one point per inch.

Point Density The number of survey data points per unit area. This may relate to field survey points or points within a point cloud generated by remote sensing methods such as LiDAR.

Relative accuracy Also called Local Accuracy. The accuracy of the position of a point in relation to other points in the dataset. Relative accuracy may exceed

Absolute (or Network) accuracy for a particular dataset. Relative accuracy is a consideration for measuring depths, lengths or areas, which are unrelated to the geospatial location of the features.

Remote Sensing Remote sensing is a survey method that obtains information about the position of objects without coming into contact with the object. LiDAR and photogrammetry are examples of remote sensing methods.

Resolution The degree of detail that is provided in a 3D dataset. For a DTM, Resolution is a product of point density and absolute accuracy.

Robotic Total Station A Total Station that automatically tracks the target and is controlled from a distance by a remote control (usually the data collector attached to the target).

RTK Real-Time Kinematic. A method of correcting systemic errors in a

GNSS position created by atmospheric perturbations. A RTK unit receives both a GNSS position and a correction and applies both in real-time to determine position. The correction is calculated and broadcast by base station of known position.

RTN Real-Time Network. A similar concept to RTK, but instead of receiving the position correction from a defined physical station, the correction comes from a virtual reference station. The correction from the virtual reference station is computed using position corrections from a network of physical stations.

Rover A mobile survey instrument with a data collector that allows the operator to determine position in real-time. The survey instrument may be an RTK GNSS receiver, a combination RTK GNSS receiver and laser-receiver, or a target for a Robotic Total Station.

Site Calibration Also called a Site Localization. A survey technique by which design grid coordinates are translated into coordinates on the ground with scaled distances. A site calibration computes a rotation and scale factor for horizontal layout and creates a vertical datum.

Site Localization Also called a Site Calibration. A survey technique by which design grid coordinates are translated into coordinates on the ground with scaled distances. A site localization computes a rotation and scale factor for horizontal layout and creates a vertical datum.

Template A parametric CADD object that defines the cross-sectional shape of an object. The template is extruded along a line in 3D space to create a 3D model. In corridor modeling, the parametric relationships in the template are calculated at defined template drop locations. In corridor models, the density of template drops defines the resolution of the 3D model.

TIN Triangulated Irregular Network. A type of DTM (see above) created by applying an algorithm (usually the Delaunay Triangulation) to connect irregularly spaced points into triangular faces. TINs are usually used to define elevation surfaces for CADD and AMG.

2. DEVELOPMENT OF AUTOMATION TECHNOLOGY GUIDELINES

The rapidly evolving technology advancements make it an enormous task for implementing agencies to update standards, policies and specifications and train their personnel to accommodate new technologies. The solution and challenge that implementing agencies must grapple with is to introduce technology agnostic, performance-based guidelines that are sufficiently flexible to adapt to change; this is a significant undertaking.

To develop guidelines for the specific automation technologies identified in Volume I requires making refinements to a broad range of policies, standards and specifications, and a body of knowledge that reaches far beyond any one individual or organization. There are significant enabling technologies and policies and staff training that must precede the use of automation in highway construction.

Though the magnitude has not yet been quantified by project type, delivery method, construction activities, duration or other factors, it is anticipated that automation in highway construction provides a number of efficiency, safety and time-saving benefits. Upfront investment may be large but incremental progress should yield positive results. Ultimately, a coordinated, performance-based approach to agency business should provide a flexible approach to maintaining a highway system in an environment that supports innovation. This would allow the selective use of automation technologies appropriate to individual project characteristics. Figure

2 outlines the workflow for incrementally modifying guidelines to support automation.

Figure 2. A workflow for developing automation technology guidelines.

2.1 OBJECTIVES

New technology is replacing less efficient technology and workflows in design and replacing less safe and less efficient practices in construction. However, policies to manage due diligence and practices to equitably allocate and manage risk in the age of automation are not keeping pace. Construction documents have not materially changed over the years. Automation in highway construction has data needs that are not supported by paper plans or by the processes and methods to develop those paper plans. The breadth of policy and practice touched by automation implementation is broad; from detailed nuances of topographic survey accuracy thresholds to retrieving as-built data from construction equipment to processing 3D data with hardware and software to measure pay quantities and accept work.

The breadth of automation technology integration means that practical and actionable implementation requires some focus on deliberate objectives. There are some logical preemptive investments, identified as “Enabling Technologies and Policies” in Chapter 4. In terms of a comprehensive strategy for automation in highway construction, the first necessary step for an agency is to define short, medium and long-term objectives for automation technology implementation.

As a leading State, Wisconsin DOT began with a process to define the impact that delivering 3D digital design data to contractors would have on institutional and legal issues, and relevant design and construction work processes. After stakeholder consultation, the objectives were broadened to 3D technologies in general (Vonderohe, 2009).

While there is strong hypothetical bias and optimism for the positive impact of Automation in Highway Construction on safety, efficiency, and construction outcomes, there is not much documented return on investment or business case analysis to guide investment in any one area before another.

Michigan DOT began with broad objectives for automation and noted anticipated benefits to using 3D engineered models and electronic data (Lobbestael, et al., 2012). In their Development

Guide, these benefits are noted to arise from:

1. More accuracy and data intelligence used in electronic design documents,

2. More accessible visualization available during the design process,

3. Enhanced ability to detect and mitigating clashes,

4. Greater ease of data migration from survey to design to construction,

5. Easier realization of the design intent during construction,

6. Better construction quality outcomes,

7. More accurate and more consumable digital as-built records, and

8. Digital data that is preserved in an accessible format for future use.

By contrast, Oregon DOT’s original implementation impetus had a narrower focus. Oregon’s contractors were noted to be using AMG in an effort to reduce construction cost. It was recognized that Oregon DOT used software and processes that could produce the necessary data for AMG operations, but there was a lack of clear guidance and consistency in the timing and nature of 3D digital data provided to contractors. (Mosier, et al., 2013)

2.2 STAKEHOLDERS

In order to develop practical and implementable policies and processes, agencies should consult with affected stakeholders with strong technical and institutional knowledge. One of the challenges to implementing guidelines for automation in highway construction is that the changes necessary to support automation technology often need to occur prior to the construction phase. While it can be empowering to the designers to let them lead the change, they do need information on the requirements for construction or the changes will not be effective. Table 1 is a list of potential stakeholders to an automation implementation and their role in the process.

Table 1: Stakeholders in Automation in Highway Construction implementation.

Stakeholder Consultation Role

Survey Topographic survey, construction oversight

Design CADD automation, 3D model reviews, design/constructability reviews, contract documents, processing survey/CADD data for construction engineering and inspection

Contracts Contract documents, bid documents

Construction Constructability reviews, field survey methods for measurement/inspection, specifications

Information Technology

Planning and specifying new information technology resources to support networked, mobile field inspection tools and new computer hardware, software and storage capacity for survey, design and contract management.

Contractors

Topographic survey requirements, 3D data requirements, impact of specifications on safety and efficiency, as-built data from AMG, field survey methods for measuring and checking work

Consultants Impact of new guidelines on business, reasonable timeline for change. Lessons learned from design-build experience.

Local public agencies Impact of new guidelines on business, reasonable timeline for change

Small businesses Impact of new guidelines on business, reasonable timeline for change

Disadvantaged Business

Entities Impact of new guidelines on business, reasonable timeline for change

State Licensing Boards Laws for digital signatures and digital seals.

Contractor association advocacy has helped to identify contractor needs and make a case for augmenting contract documents with 3D digital design data. Many design automation departments have made changes to the way 3D data is used in design and then shared prior to bid. Construction specifications have been modified or special provisions created to allow optional AMG construction with reduced staking and some obligations to provide equipment and training. Construction engineers and inspectors are beginning to develop digital methods for construction oversight. Some state transportation departments have created special provisions to enable contractors using AMG to provide equipment and training for inspectors. This has left most State construction departments in a reactive position for implementing automation via digital, 3D data-driven workflows for measurement and acceptance. With more consultation with construction surveyors, broader usage cases may be identified for real-time field verification processes for measurement and acceptance. (Struthers, et al., 2015)

There has been much focus on the 3D digital design data upon which many automation technologies rely, but many automation processes also rely heavily on survey equipment and methods. While construction surveying is typically not a licensed practice, there is a very important role for surveyors to play in planning and implementing automation policies and guidelines (Darter, et al., 2015). Contractors are important partners because they have the most experience with automation and have been using automation technology at risk. Consequently, many contractors have implemented procedures internally that optimally balance the cost of data acquisition and preparation with the benefits of efficient, high-yield operations.

2.3 POLICY AREAS

A number of current policies and specifications can be revised to accommodate automation in highway construction. These changes can be managed within the current policy framework. With two notable exceptions, the changes are within the control of the state transportation department.

The exceptions are laws governing use of digital signatures and digital seals on engineering contract documents, both of which are usually controlled by the State licensing board.

As the primary sources of policy for digital data, the Survey, Design, and CADD manuals could be modified to include provisions for creating and delivering the 3D data that automation technologies need. Many States have a Construction Manual that provides guidance to construction managers and inspectors in conducting their activities. Recommended modifications to manuals are shown in

Table 2.

Table 2: Recommended modifications to manuals.

Manual Recommended Adaptations

Survey Manual

See Chapter 6

Considerations for establishing site control.

Inclusion of metadata.

Accuracy tolerances for topographic surveying.

Use of remote sensing.

Non-traditional survey products.

Design Manual

See Chapter 7 and 8

Subsurface utility locating technologies.

Potential applications of 3D models in design development.

Possible revisions to standard details.

Creating a 3D Model standard.

Creating 4D and 5D Model specifications.

Implementing 3D data review protocols.

Processes for creating contract documents and bid reference documents.

CADD Manual

See Chapter 8

A 3D model guide specification that defines standards for creating and managing 3D models, in addition to standards for the outputs from 3D models.

3D data review protocols.

Construction Manual

See Chapter 10

Construction data management.

Low accuracy positioning.

High accuracy positioning.

Automation processes for construction engineering and inspection.

Corridor models are an effective way to model for AMG equipment because the broad brush of a

15-ft long blade can be replicated digitally with a corridor template. When implementing automation in highway construction with a desire that design data should be used directly by contractors and inspectors, it is an opportunity to revisit standard details to determine if changes could provide efficiencies in modeling and in construction. Specific areas that may be affected are introduced in Chapter 8.2.

As construction methods change rapidly with evolving automation technology, new document and data types are introduced that do not have contract language to manage them. Automation technology implementation provides an opportunity to review, measure, and accept work based on digital objective evidence.

Guide specifications are provided in Chapter 9. There are guide specifications for accommodating automation in highway construction with modifications to the following sections of the standard specification:

1. Controlling Work: Plans and Working Drawings.

2. Controlling Work: Conformance with Plans and Specifications.

3. Controlling Work: Construction Stakes, Lines and Grades.

4. Controlling Work: Inspection of Work.

5. Controlling Work: Quality Control Plan.

6. Measurement and Payment.

7. Earthwork, Fine Grading, Base Course and Paving.

2.4 CAPITAL AND HUMAN RESOURCES INVESTMENTS

Automation in highway construction creates a paradigm where skilled professionals execute their work in a streamlined, digital environment that replaces manual tasks with automation. Some of the benefits of automation include fewer workers exposed to heavy equipment or less time to execute inspection tasks (Darter, et al., 2015). However, automation in highway construction is not perceived as an opportunity to reduce the construction workforce. Rather, it is an opportunity to produce better construction outcomes by introducing processes that allow inspectors to document as they inspect and spend more time observing construction. This involves investing in people to create a highly skilled workforce that makes use of sophisticated hardware and software.

2.4.1 Hardware

Hardware may be needed in the survey, design or construction offices. It is less common that survey and design hardware needs upgrading. Provision of equipment and training for construction field staff can be managed in a variety of ways. An agency may purchase equipment, lease equipment or the contractor may furnish equipment for the duration of construction (Struthers, et al., 2015). The latter may be attractive because it takes procurement out of a capital budget. However, when furnishing the equipment is a line item in a bid for optional use of automation technology contractors may consider this detrimental to their ability to be competitive and may be a disincentive to the use of automation.

2.4.2 Software

Investment in software goes beyond the cost of the software licenses and support agreements.

Most agencies have invested in software standardization and CADD automation to provide consistency in datasets and efficient data creation. With new software comes the cost of creating new standards and new automation tools. There is also a cost associated with migrating or accessing legacy datasets.

New software may be needed for survey, design and construction staff to support automation in highway construction. Software to manipulate and process LiDAR data is rapidly evolving.

Many agencies are in the process of evaluating or updating their CADD software for design.

There may be a need for new CADD software licenses for construction staff to use on site.

Construction staff may wish to review the contractor’s AMG models, create staking data, evaluate potential design revisions, or process as-built survey data to measure or accept completed work. CADD software used by the survey and design office may fulfill these purposes, or construction software may be a better fit.

2.4.3 Changing Job Functions

Until recently, construction surveyors set the stakes and hubs that translated the information on the plans into a format that was interpreted on the ground in a consistent manner by the contractor and inspector. Automation technology perform layout in real-time using position sensors and an on-board computer or hand-held data collector. This places layout in the hands of the equipment operators and inspectors who usually are not surveyors. Consequently, the adoption of automation in highway construction requires broader understanding of survey methods.

With automation technology, construction surveyors have a changing role from pounding stakes and hubs to providing oversight. By contrast, preconstruction job functions are not materially affected. Surveyors have new considerations for control and topographic survey accuracy.

Designers need to add more detail, document designs in new digital formats and data types, and create protocols to review the digital data. Contracts officers need to ensure that contract language and specifications adequately address the use of digital data in construction.

2.4.4 Training Needs

New workflows that replace laborious, manual processes with automation is the goal of automation in highway construction. As a consequence, the training needs created by automation technology implementation are vast. The need for training is one of the most often cited barriers to implementation. There are different levels of training that are needed at different times.

Webinars or short presentations can raise awareness by disseminating information, but often does not advance implementation. Many agencies have found that hands-on training in new methods and processes can be delivered in the classroom or online (Struthers, et al., 2015).

An integrated automation technology implementation affects surveyors and designers who typically are not involved in construction. Overview training of how the changes imposed upon them improve outcomes in construction can be beneficial. Some states have provided this through outreach to stakeholders at annual consultant or contractor association training conferences. Florida DOT hosts an annual Design Expo where there have been many of such sessions and the archive of presentations is available online.

Once new policies, specifications or standards are created, these need to be implemented and some changes may affect how people do their jobs. Practical, hands-on training needs are greatest in 3D design, use of CADD automation, and in methods for performing real-time verification (Darter, et al., 2015). Just-in-time training has been found to be most effective for hands-on training in workflows or new software tools (Struthers, et al., 2015). Training in survey principles and real-time verification methods can be provided to construction field staff through a provision in a Special Provision or Specification. This option is described in the guide specifications in Chapter 9.

3. IMPLEMENTATION STRATEGIES

The culture at an implementing agency will affect the way in which automation in highway construction will be mainstreamed. State transportation departments have taken different paths to implement automation technology with some adopting a formal, agency-wide implementation plan while others adopting it on a project-by-project basis based on resources and interest at a regional/local level. In the view of the authors of this report, a formal plan is not essential to advancing implementation. The common thread to how transportation agencies moved implementation forward rapidly is that a small team with decision-making power and executive sponsorship managed the implementation.

The need to explicitly quantify the benefits of implementing 3D Models and their related automation technology uses before any investments are made to change the traditional business practices would be a significant obstacle. Quantifying the benefits of implementing automation in highway construction is a particularly difficult challenge. A majority of the costs overruns associated with the traditional project delivery process accrue in the construction phase in the form of errors, omissions, inaccurate quantities, unresolved transitions that need to be field fit, and in the perpetuation of construction methods and inspection protocols that could be made safer and more effective. However, the investments to realize the benefits of automation must be made in the project scoping and design phase through accurate survey and 3D Model development that facilitates better construction.

Implementing enabling technologies and policies to create 3D data during design is a first necessary step and can be managed within a design or a design automation department. Putting

The implementation of Automation in Highway Construction should be viewed in a holistic manner and should include costs and benefits spread across all project phases at a programmatic level to leverage the cost efficiencies associated with targeting a program of projects rather than a single project.

the 3D data to work in the field (and post-construction) takes a coordinated effort from multiple departments. Input from the range of stakeholders identified in Chapter 2.2 above is important.

3.1 FORMAL IMPLEMENTATION PLANS

Creating a formal implementation plan to mainstream automation in highway construction is a recommended strategy. An implementation plan is a means to recognize the totality of actions to consider, identify the various internal and external stakeholders and to facilitate the broad collaboration required to achieve the end result. Writing the plan is only part of the journey;

executing the plan is where the majority of the effort occurs. The implementation plan should provide a structured approach to mainstreaming automation, create a clear purpose for implementation, set goals, establish criteria for success, and provide for input from people with multiple perspectives to identify opportunities for success and plan to overcome obstacles.

Figure 3 is a sample flowchart for the implementation process.

Figure 3. Implementation Process.

As shown in Figure 3, common elements of an implementation plan include:

The Vision for the future post-implementation that provides a broad message that unifies the organization in support of the plan.

The Purpose and Need establish a logical case for why change is needed. This helps to secure executive sponsorship and funding for the implementation.

Known Issues that may provide obstacles to the implementation if managed or overcome.

Goals that align with the agency or organizations strategic goals. Goals are outcomes that are intended by the implementation.

Team Members who will be responsible, accountable, consulted and informed of activities in the plan. These are people who will do the work and people who will be affected by the consequences of implementation tasks.

Activities that describe the steps taken to implement the plan.