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39 This chapter documents the uses and the practices as reported by seven state DOTs that demonstrated experience with innovative technologies for construction project delivery. The case examples of selected state DOTs document information regarding technology implementa- tion, use, benefits, challenges, and lessons learned for construction project delivery. Selection of Case Examples Data collected from the literature review and the survey questionnaire were used to identify state DOTs for further study using the following criteria: â¢ Experience with the use of various technologies in at least three of the five technology areas, â¢ Comprehensiveness and availability of documents and data, and â¢ Willingness of agency staff to participate. On the basis of these criteria, 14 DOTs from across the United States were selected initially for the case examples. Solicitation for participation occurred through phone calls and e-mails. Then, on the basis of the contacts made and the availability of DOT staff, the following seven DOTs agreed to participate in this study: Minnesota, New York State, Ohio, Pennsylvania, Utah, Washington State, and Wisconsin. Participation involved conducting structured interviews with state DOT staff that interacted with each of the technologies, collecting documents and reports, and reviewing the findings with staff for accuracy. The following is the case example protocol used in this synthesis to conduct the case examples: 1. Contact DOT representatives to request participation in the case example. Because of the various technologies investigated, several DOT contacts, with knowledge of and expe- rience with specific technologies, were provided by the initial contact representative for each case example. 2. Conduct interviews with key agency staff to identify the uses, benefits, and challenges of emerging technologies for construction project delivery and potential strategies to overcome challenges. Specific attention was paid to the ease of implementation and perceived benefits in using the technologies. 3. Collect documents and reports regarding the implementation, use, and regulations for technologies in construction delivery. 4. Follow up with the DOT representatives interviewed to verify the results documented in the case example and to obtain any additional information as needed. An interview questionnaire for each case example was structured around seven areas: (1) general information and use of technologies; (2) visualization and modeling technologies; (3) interconnected technologies for construction vehicles, equipment, and handheld tools; (4) safety C H A P T E R 4 Case Examples Using Technologies for Construction Delivery
40 Emerging Technologies for Construction Delivery technologies; (5) instrumentation and sensors; (6) UASs; and (7) final thoughts and lessons learned. This chapter documents the findings in a similar order as the interview questionnaire for each case example. Minnesota Department of Transportation Minnesota DOT constructs and maintains more than 29,000 lane miles of state and federal highways throughout the state. Annually, the department performs approximately 250 con- struction projects worth more than $1 billion in state and federal funding. Currently within Minnesota DOT, the Office of Construction and Innovative Contracting (CIC) promotes the use of many technologies included in this synthesis. Table 16 summarizes the types of technologies Minnesota DOT uses for delivering highway projects. Use of Technologies for Construction Project Delivery The Minnesota DOT considered the use of technologies to improve construction efficiency. The perception of the Minnesota DOT and the contractors working with it was that many tech- nologies available enabled them to perform tasks more efficiently, and subsequently improve labor productivity. The Minnesota DOT staff indicated that they constantly looked for technolo- gies to make the physical labor of a construction project more efficient. In recent years, the push for the use of various technologies resulted from Minnesota DOTâs e-construction initiative. When FHWA released EDC-3, Minnesota DOT was a leader in its Technology Types Uses Visualization and modeling â¢ Building information modeling â¢ Virtual reality and augmented reality â¢ LiDAR â¢ Wearable visualization devices â¢ Constructability reviews â¢ As-built documentation â¢ Construction simulations of bridges and structures â¢ Virtual design and construction â¢ QA/QC â¢ Construction inspections Interconnected technologies â¢ Earthwork equipment â¢ Paving equipment â¢ Haul vehicles â¢ AMG â¢ Location of vehicles and equipment â¢ e-ticketing â¢ Performance monitoring â¢ Inventory management Safety technologies â¢ Proximity warning alarms â¢ WZIAs â¢ DMSs â¢ VSLs â¢ Dynamic lane merging â¢ Automated cone placement and retrieval â¢ Accident avoidance â¢ WZI for motorists â¢ Removal of workers from harmâs way â¢ Enhanced protection for workers â¢ Incident tracking and analysis Instrumentation and sensors â¢ Audio/video/CCTV â¢ Remote sensing â¢ â¢ â¢ Structural integrity sensors Environmental conditions sensors Specification measurement sensors â¢ As-built documentation â¢ Monitoring of progress of work â¢ Location of materials â¢ Location of utilities â¢ Identification of optimal work conditions â¢ QA/QC â¢ Construction inspections Unmanned aircraft systems â¢ Multirotor â¢ Fixed wing â¢ Safety management â¢ Construction inspections Table 16. Technology types and uses for Minnesota DOT highway projects.
Case Examples Using Technologies for Construction Delivery 41 efforts to move toward a paperless delivery process. The agency issued tablets to field personnel to use apps that assisted with construction-related processes and reduced or eliminated the need for paper documents. Further, Minnesota DOT used cloud-based servers to exchange and share real-time data with project participants during the development, design, and construction of a project. Some of the e-construction processes demonstrated that using certain technologies made construction projects more efficient to manage and construct. Minnesota DOT staff reported that new technologies were a welcome addition to current tools. The agency encouraged contractors to use technologies to deliver highway construction projects efficiently. Contractors working with Minnesota DOT requested the use of a specific technology for their construction means and methods, which MnDOT indicated they typically allowed as long as the technology did not compromise the project specifications or increase cost. While Minnesota DOT stated that they tended to lag behind contractors in the level of sophis- tication and use of technologies, the collaboration with their contractors has helped Minnesota DOT move toward greater use of technologies for construction projects. Although technologies positively influenced construction project delivery at MnDOT, one reported concern was how to adapt the technology to current processes and to use all collected data in an informative manner. The initial investment of resources toward the use of a technol- ogy tended to take time to gain interest and approval, even though Minnesota DOT may see the long-term benefits of a technology. Further, the legal staff at Minnesota DOT voiced concerns about the security of the data collected, how to keep the data safe and confidential, and what data were public information. Visualization and Modeling The Minnesota DOT began its investigation of the use of 3-D modeling ten years earlier and has advanced its use in visualization and modeling technologies within the past few years. To aid with the use of visualization and modeling technologies, upper management recently created the position of program delivery software manager. The managerâs responsibilities were to advance the use of 3-D and 4-D design and modeling and to provide leadership and support for the use of software programs for project management and delivery. From a legal perspective, Minnesota DOT staff indicated that they provided project design models to contractors for their discretionary use. Contractually, 3-D models were not a part of the contract documents, and the traditional 2-D plans still prevailed in the case of discrepan- cies. Yet, contractors continued to request 3-D models for AMG using electronic grade control for earthwork activities. Minnesoa DOT was investigating the process of developing, delivering, and incorporating 3-D models into the contract documents as MnDOT planned to phase out 2-D paper-based plans and to use 3-D digital models. Interconnected Technologies Many paving and earthwork contractors that contracted with Minnesota DOT used AMG and electronic grade control during construction for paving and earthwork operations. Minnesota DOT reported that a recent advancement complementing AMG was the use of intelligent compaction and paver-mounted thermal profiling devices. Minnesota DOT began using intelligent compaction and thermal profiling as a pilot project in which the agency pro- vided the equipment, devices, and software package to contractors for their use and feedback. Intelligent compaction uses pavement roller equipment that is instrumented with advanced technology devices along with GPS and wireless connectivity so that the devices take con- tinuous measurements of the asphalt compaction and transmit all data to a cloud server for
42 Emerging Technologies for Construction Delivery further analysis. Thermal profiling uses paver equipment that has an infrared temperature sensor system mounted to it that takes temperature readings during the asphalt paving process, creating a thermal profile of the pavement using a cloud-based server and software package. Minnesota DOT incorporated intelligent compaction and thermal profiling into all asphalt paving projects as the agency realized that these technologies might increase the overall life of the asphalt pavement and decrease annual roadway maintenance costs. Therefore, asphalt contractors that regularly worked with Minnesota DOT needed to possess these technologies; otherwise, the contractors would have been unable to do business with Minnesota DOT. This approach essentially forced the contractors to use a technology that MnDOT had deemed to add value to construction projects. Another area of interest to Minnesota DOT was the use of e-ticketing. The MinneapolisâSaint Paul area was working with a heavy equipment vendor and a local contractor to perform the first pilot test of e-ticketing for a project with asphalt paving. One of the primary benefits that Minnesota DOT saw in the use of e-ticketing was a safety practice to remove individuals from harmâs way as well as increased efficiency with asphalt materials and paving. With the traditional approach, a load of asphalt from a truck is automatically weighed, and a paper ticket is created and provided to the truck driver. Once the asphalt load is brought to the site and unloaded, the truck driver gives the ticket to a person in the field. Each time a load is dumped, someone in close proximity to moving heavy equipment takes a ticket. Using e-ticketing removes that person from the process and still satisfies FHWA by collecting real-time tickets as the unloading of a pavement material occurs. A second asphalt e-ticketing pilot project was planned for the near future, and Minnesota DOT plans to move toward e-ticketing for concrete pavement projects as well. Safety Technologies Safety is one of the core values of Minnesota DOT and is a primary concern to make sure workers safely perform work and travelers move safely through a work zone. Recently, Minnesota DOT began to look at how to place more emphasis on safety and enhance safety practices for construction work zones. This concept led Minnesota DOT to develop a toolbox of intelligent work zone systems. The toolbox allowed MinnesotaDOT to standardize the terminol- ogy and uses of advanced work zone safety tools. Some guidelines already developed for intelligent work zone systems at Minnesota DOT included conflict-warning systems, congestion-warning systems, dynamic lane merge systems, and travel time systems. Conflict and congestion warning systems are stand-alone systems that detect congestion or slowing traffic in an approach to a work zone and alerts upstream motorists that traffic is slowing down ahead. Dynamic lane merge systems, shown in Figure 26, vary the merging location at a work zone on the basis of the level of traffic flow. Low traffic volumes allow for early lane merging while congestion invokes delayed lane merging that instructs vehicles to alternate merging into one lane. Travel time systems calculate the approximate time from one location to another on the basis of the traffic volume and number of lane closures, and this time is broadcasted to traveling motorists using DMS. Instrumentation and Sensors Minnesota DOT developed a software program called VETA, an intelligent construction data monitoring system. VETA, a postprocessing and nonproprietary software, uses intelligent com- paction and thermal profiling data to map, edit, and analyze pavement performance, the project specifications, and compaction curves on the basis of the equipment-rolling pattern. Although VETA does not provide real-time mapping and does not provide data on live compaction
Case Examples Using Technologies for Construction Delivery 43 activities, VETA helps to analyze the massive amounts of data collected by the intelligent com- paction and thermal profiling devices. An example of implementing an instrumentation device comes from one of the Minnesota DOT districts in western Minnesota, in which the resident construction engineer used RTK rover devices for data collection and conducting inspections. A projectâs 3-D model is incorporated into the RTK rover device, and users then have a 3-D view of the project. In some instances, the model is loaded into the RTK rover before construction; this sequence allows field personnel to catch various errors and omissions before placement of work. Then, during construction, the RTK rover measures the project specifications, such Figure 26. Dynamic lane merge process used by Minnesota DOT.
44 Emerging Technologies for Construction Delivery as concrete pavement depth, on a continuous basis and with better accuracy than traditional inspection tools and methods. Unmanned Aircraft Systems Minnesota DOT explored the use of UASs for various applications including construction activities. As stated by transportation staff, the issue that impeded further investigation and the initial use of UAVs was the concern that senior leadership had for UAV use and the various strict regulations from FAA. Yet, with limited experience and regulatory barriers to the use of UASs, Minnesota DOT staff indicated potential for using UASs for monitoring environmental conditions such as erosion control and for inspections of areas that are difficult to reach, such as around bridge structures. Lessons Learned Minnesota DOT reported the following lessons learned from the use of emerging technologies for highway construction: â¢ Collaborate with other state DOTs. By collaborating with neighboring state DOTs, Minnesota DOT indicated that it became more aware of promising technologies. Once the agency initiated the investigation on the use of a technology, working with neighboring state DOTs assisted Minnesota DOT in learning about a technology. Another benefit was that contractors working with Minnesota DOT normally worked with the neighboring state DOTs as well. The use of similar technologies between states provided contractors with consistency and the ability to become an expert in the use of technologies. â¢ Understand the reasons to use technologies. Minnesota DOT noted the importance for staff to have not only a knowledge of the various technologies in use, but also an under- standing of the business side of a DOT. As technologies were adapted, Minnesota DOT reported the importance of having information technology staff who knew the technology in use and how that applied to the business strategy of constructing highway projects in the state. â¢ Leadership needed to champion the use of a technology. A leader or champion of a technology was needed to help implement and advance a technology at Minnesota DOT. For MnDOT to prove the value of a technology, leadership within the department was necessary to promote its use, gain approval, and educate users and the traveling public. New York State Department of Transportation The New York State DOT leads and assists with the construction and maintenance of more than 110,000 miles of roadways throughout the state, which includes the largest metropolitan city within the United States. With an annual construction budget of around $1.4 billion, New York State DOT constructs approximately 300 projects each year, currently ranging in cost from hundreds of thousands of dollars to well more than two billion dollars. The importance of the roadway system in New York, paired with the limited DOT annual budget, means that the New York State DOT has a responsibility to be as efficient as possible. To improve construction efficiency, the agency used or encouraged contractors to use innovative and emerging technologies, including visualization and modeling of construction projects and tasks, interconnected technologies for earthwork and paving operations and tracking and locat- ing vehicles, communication devices for construction work zone safety, instrumentation devices and sensors for evaluating work and inspections, and UASs. Table 17 lists the technology types and their use for construction delivery of highway projects at New York State DOT.
Case Examples Using Technologies for Construction Delivery 45 Use of Technologies for Construction Delivery Contractors were instrumental in encouraging the New York State DOT to explore the use of emerging construction technologies. New York State DOT staff mentioned that the highway construction contractors that worked with New York State DOT realized the benefits and time savings associated with the use of technologies and began developing their own 3-D models for various construction activities, such as AMG. Furthermore, the agency observed that the technically well-informed contractors were exploring various technologies and using them with increased frequency; this activity increased the demand for 3-D design and the request for the New York State DOT to provide contractors with project models. Agency staff realized that creating the model internally and providing it to the contractors provided cost savings since the contractor previously built this cost into estimates. The New York State DOT developed 3-D models that contractors used as a basis for their means and methods. To quantify the benefit of using innovative technologies during construction, the New York State DOT documented the time savings on a project that used various technologies and made a comparison to traditional approaches. Table 18 summarizes some of the time savings experienced on the Parksville Bypass project in Parksville. This project was one of the first projects in the state to use tablet and GPS devices in the field, which field personnel used to view a model of the site and to determine exact locations for excavation and site work. Further, the third-party inspection firm for this project used specialized software to make real-time calculations of quantities and volumes of materials, which were determined to be more accurate than more traditional field quantity measurement techniques. Technology Types Uses Visualization and modeling â¢ BIM â¢ VR and AR â¢ LiDAR â¢ Virtual prototyping â¢ Constructability reviews â¢ As-built documentation â¢ Simulating construction of bridges and structures â¢ QA/QC â¢ Construction inspections â¢ Project controls Interconnected technologies â¢ Earthwork equipment â¢ Paving equipment â¢ Haul vehicles â¢ AMG â¢ Location of vehicles â¢ Maintenance and performance monitoring â¢ Asset management Safety technologies â¢ DMSs â¢ VSLs â¢ Accident avoidance â¢ WZI for motorists â¢ Incident tracking and data collection â¢ Work zone traffic management Instrumentation and sensors â¢ Remote sensing â¢ Structural integrity sensors â¢ Environmental conditions sensors â¢ Specification measurement sensors â¢ Evaluation of structural members â¢ Verification of design during construction â¢ QA/QC â¢ Construction inspections â¢ Project controls UASs â¢ Monitoring progress of work â¢ Construction surveying â¢ Site mapping â¢ Material inventory â¢ Construction site security â¢ Construction inspections â¢ Traffic control and surveillance Table 17. Technology types of and uses for New York State DOT projects.
46 Emerging Technologies for Construction Delivery Visualization and Modeling Initially, contractors created 3-D models for projects to improve their means and methods and work productivity. As time went on, contractors began requesting 3-D models from the New York State DOT so that they did not have to create the model themselves. The agency now creates 3-D models for projects that contractors use. By providing the model, New York State DOT observed reductions of around $100,000 in each bid. These savings were attributed to the contractor not having to create the model and the ability to be more accurate in estimating quantities. Initially contractorsâ use of 3-D models to assist with means and methods meant that the contractors were able to be more efficient and quicker in their work and pace, but the inspection process used traditional methods that slowed down the contractor. As a result, the New York State DOT used GPS devices and advanced robotic total stations in the field during construction. As reported by DOT staff, the use of GPS and advanced survey equipment in the field helped to manage labor needs for surveying and inspections efficiently, such that one surveyor was needed to use a robotic total station. In the past, surveying took at least two or more people, as well as expending more worker-hours to complete the task. New York State DOT developed and then provided 3-D models to contractors as supple- mentary information for their discretionary use. However, New York State DOT staff reported that the 3-D model was not a part of the contract documents and that the traditional 2-D plans were still used to resolve disputes. However, the agency was in the process of developing a pilot program involving two to four projects that would use contractual 3-D models in the next few years. New York State DOT planned to invite contractors to bid on these piloted proj- ects, but only if they were willing to work together with the agency and understand the conditions. New York State DOT staff mentioned using visualization and modeling for major and com- plex projects and provided contractors with a 3-D model with automation information for bidding purposes. For large and highly visible projects, the transportation department was investigating the move toward the use of 4-D and 5-D models. At the completion of projects, New York State DOT instructed the contractor to deliver a 3-D as-built model as well as an as-built GIS model that included a list of assets. In fact, one of the regions of the New York State DOT required that all asset information be collected by using an RTK rover device, which the contractors were will- ing to purchase and use because of the initial success. Task Technology Equipment Process Savings Footer excavation GPS and 3-D model Either stake DTM or gather topographic shots and check with InRoads. Check the footer grade with GPS. Required 6 fewer worker-hours per footer Silt fence GPS Used to measure and record silt fence and temporary ROW fence location 50% faster than traditional methods Checking slopes/distances GPS Take shots at two locations and compute the distance and slope. 67% faster than traditional methods Temporary earthwork GPS and 3-D model Used to calculate earthwork volumes. Required 6 fewer worker-hours per day Site seedingâ temporary and final GPS and 3-D model Used GPS for perimeter, InRoads for surfaces. Required 14 fewer worker-hours per day Table 18. Recorded savings with the use of technologies for the Parksville Bypass project.
Case Examples Using Technologies for Construction Delivery 47 As its 3-D visualization and modeling technologies evolve and improve, the New York State DOT indicated that it was addressing file transfer issues because of the availability of various software programs and equipment for use by contractors. For example, the agency used a specific vendor for surveying, which used DWG files. Contractors may use other equipment, which uses CSV files. In conversations New York State DOT had with the con- tractors on data transfer, an agreement was established to share XML files, as they are useable in most software packages. Interconnected Technologies The use of AMG by contractors for earthwork and paving operations was implemented on a regular basis. Some of the initial 3-D models created by the New York State DOT contained more data points and information than necessary for the contractor for AMG. Therefore, agency DOT staff mentioned that they were working with contractors to simplify the 3-D model infor- mation into a usable form for contractors without requiring large amounts of time refining the file for their specific use. For vehicle and equipment locations and monitoring, most contractors that worked with the New York State DOT had construction equipment and hauling vehicles equipped with GPS to locate them visually and to determine speed and direction. As noted by the department, by geolocating equipment and vehicles, contractors could reduce and sometimes eliminate idle time in the hauling. Furthermore, the New York State DOT indicated that it was piloting e-ticketing for pavement projects. Safety Technologies Safety was a primary concern for the department, not only in construction work zones, but also along its entire highway infrastructure system. The New York State DOT used intrusion detection systems to warn workers in work zones when a vehicle or object inadvertently entered the zone. The DOT was testing the use of balloon lighting for nighttime construction in work zones. Balloon lighting is a type of site lighting system that provides the most optimal lighting conditions for nighttime construction work without the noticeable glare and shadows that are apparent with traditional lighting systems that cause distractions to the traveling public. The balloon lighting system is versatile as it is quickly set up and taken down and is completely mobile, and the balloon lights are interchangeable, depending on the activity or tasks taking place. Many of the balloon light bulbs use light emitting diodes (LEDs), which offer greater durability and less susceptibility to inclement weather than traditional incandescent or halogen luminaires. Additionally, the New York State DOT indicated that it was using halo lighting for workers. Halo lighting, shown in Figure 27, is an LED lighting system located along the brim and around a workerâs hardhat. The halo lighting provides a better view of a worker in a nighttime work zone than one with a single direction flashlight attached to a helmet. In both balloon and halo lighting, NYSDOT saw the benefits in their use and received mostly positive feedback in their use. A drawback to these two lighting systems is that both are expensive commodities compared to traditional work zone lighting safety systems. Instrumentation and Sensors Within each of its 11 regions, the New York State DOT has a set of survey coordinators. Yet, as New York State DOT staff indicated, when the department worked on hundreds of construction and maintenance projects each year, the limited number of survey coordinators in each region could not keep up with the work. To alleviate the amount of work on the survey coordinators,
48 Emerging Technologies for Construction Delivery the New York State DOT began training its inspectors to use technologies in the field to check the accuracy of work put in place. The training included using GPS and 3-D models in the field to mea- sure specifications and quantities. The inspectors in the field were then provided with handheld technological devices that allowed the inspectors to collect quantities using GPS. Additionally, the departmentâs highway projects had the contractors supply their own supervisors in the field with GPS devices. With both the department and the contractors taking measurements in the field with GPS devices, the New York State DOT and contractors noticed that the accuracy in quantities improved and the measured values by the contractors and the department showed lower variances. The New York State DOT reported that it also used GPR for inspection and quality manage- ment purposes. The agency was in the process of developing underground tomography, similar to an X-ray of the ground beneath a project, to help locate utilities and other potential obstruc- tions before excavation began. The plan was to provide the tomography and the 3-D model to a contractor to use on a project. Inspections of these projects can use the digital tomography and the 3-D model along with field GPS instrumentation and sensor devices to place the work accurately. Specifically, for using construction surveying technologies, the New York State DOT indi- cated that it developed a contract control plan, a way to have contractors verify that they used the same control method as the departmentâs design team. The department required contractors to verify the original ground truth of existing terrain and to ensure agreement with the New York State DOTâs expectations for calculating quantities. The agency noted that having a contract control plan and establishing the original ground truth helped to reduce disputes. Unmanned Aircraft Systems The New York State DOT did not possess the authority to use UASs directly for construction activities. However, contractors working for the department were not held to the same regula- tions and used UASs for a variety of construction activities related to bridge inspections and progress monitoring. Regarding contractors using UAVs to fly over a site on a regular basis, the New York State DOT mentioned a requirement that if contractors noticed a discrepancy when flying a UAV over a site, contractors were to notify the department t of the discrepancy and were then to conduct a more detailed survey. The detailed survey was then provided to the New York State DOT for review. Although the state DOT did not have authority to use UASs, there were on-going efforts to gain formal authority. On the basis of benefits seen in contractorsâ use of UASs, the New York State DOT staff reported that they were in the process of meeting with state and federal officials Figure 27. Halo lighting system attached to a hard hat for work zone workers (Hedmond 2017).
Case Examples Using Technologies for Construction Delivery 49 to learn how to change the status. As an example of the benefits of UASs, the department needed 3 years and 30 people to evaluate the compliance of 8,000 handicap ramps by using mobile and ground-based LiDAR equipment. Conversely, a consultant using a UAV with attached surveying equipment collected data on 1,000 handicap ramps and evaluated them in 3 hours. Lessons Learned As reported by the New York State DOT, some lessons learned from using innovative tech- nologies for construction delivery follow: â¢ Use of the same control points. When using 3-D models and technologies in the field, the DOT mentioned the importance for the agency and contractors to use the same control points. Verifying and using the control and the original ground truth help to ensure that the New York State DOT and contractors are using the same data for calculating quantities. â¢ Training inspectors to use technological devices in the field. The DOT noted that training inspectors to use technologies, such as GPS handheld devices and 3-D models, helped field operations become more efficient and inspections to become more accurate. Ohio Department of Transportation The Ohio DOT constructs and maintains more than 43,000 lane miles of state and federal roadways that handle the fourth largest volume of commercial freight along the fourth largest Interstate network in the United States. The department constructed approximately 1,100 proj- ects, with a capital cost of around $2.33 billion in 2017 and $14 billion spent on transportation construction projects since 2011. The implementation of innovative and emerging technologies varied, with the use of modeling and visualization technologies the most mature, though considered by Ohio DOT staff to be in the pilot stage. Various safety technologies were in place for urban roadways that required traffic management. Recently, the state of Ohio created the DriveOhio divi- sion to handle interconnected vehicles, which encompassed interconnected technologies for construction. Ohio DOT also employed various instrumentation and sensors technologies for inspections and continued to explore the use of UASs to perform construction-related activities. Table 19 outlines the technologies in use for construction delivery as noted by Ohio DOT. Use of Technologies for Construction Delivery As reported by Ohio DOT staff, the traveling public and the state legislature constantly asked for large and complex projects to be delivered faster. Because of this situation, the department realized several years earlier that the use of technologies could make construction delivery more efficient. One of the first endeavors undertaken by Ohio DOT was the move to a paperless e-construction delivery process, which included initiatives such as maintaining documents in cloud-based databases and allowing contractors to access SiteManager to approve change orders electronically. Further, department staff mentioned that they would like to see contractors pro- vide estimates and sign documents electronically. Ohio DOT planned to move toward reducing the use of 2-D plans in favor of 3-D digital models. Department staff explained that they used performance specifications to allow contractors to determine technologies that may be needed to adhere to the project specifications. Ohio DOT did not specify the technologies to use; contractors make those decisions. The flexibility in allowing various technologies for construction helped contractors to implement what they
50 Emerging Technologies for Construction Delivery needed to perform successfully. On the basis of feedback from agency staff, contractors liked the flexibility in using innovative and advanced technologies, which allowed them to use technolo- gies that made them more efficient and provided greater cost savings. The combination of using performance specifications and the ability of contractors to use technologies permitted better accuracy and potential cost savings. Department staff noted that bids were more accurate when contractors used technologies to prepare a bid and projects tended to have fewer change orders when technologies were used during construction. The most common barrier mentioned by Ohio DOT staff to the use of technologies for con- struction was the lack of technical skills possessed by department employees. Despite this con- cern, the department had not implemented formal training in these technologies. However, staff reported plans in place to develop formal training for visualization and modeling technologies as well as UASs. To understand and to learn about visualization and modeling technologies, Ohio DOT brought in software and hardware vendors to explain the technologies. The next step was hiring consultants to provide training and to supplement users in areas where department staff lacked knowledge and skills. As the pilot testing for visualization and modeling continued, Ohio DOT reported its hope to move forward with consultants to train staff to improve their knowledge base and skill sets. Significant factors in the success of using technologies were the cooperation of the contrac- tors that performed work for Ohio DOT and the cooperation between design and construction personnel. Cooperation was attributed to contractorsâ request that the department move for- ward with the use of technologies for construction delivery; the consensus was that contractors wanted to use technologies with potential and realized benefits. In the past, as staff noted, the department tended to push contractors to work in a certain way, but with the infusion of more technologies into the construction process, Ohio DOT was listening to contractorsâ requests to use specific technologies. Visualization and Modeling Ohio DOT staff mentioned that the overall goal was for the department to use 3-D for most projects in the future. As part of its e-construction initiative, Ohio DOT planned to Technology Types Uses Visualization and modeling â¢ Building information modeling LiDAR â¢ Constructability reviews â¢ Simulation of construction of bridges and structures â¢ QA/QC â¢ Construction inspections Interconnected technologies â¢ Earthwork equipment â¢ Paving equipment â¢ AMG â¢ Location of vehicles Safety technologies â¢ Proximity warning alarms â¢ WZIAs â¢ DMSs â¢ VSLs â¢ Queue detection system â¢ Intrusion detection â¢ Enhanced protection for workers â¢ WZI for motorists â¢ Work zone traffic control â¢ Incident tracking and analysis Instrumentation and sensors â¢ Remote sensing â¢ Specification measurement sensors â¢ Environmental conditions sensors â¢ Monitoring progress of work â¢ Location of utilities â¢ Placement of work â¢ QA/QC â¢ Construction inspections UASs â¢ Construction documentation â¢ Construction surveying â¢ Construction inspections â¢ Table 19. Technology types and uses for Ohio DOT projects.
Case Examples Using Technologies for Construction Delivery 51 move from 2-D printed plans to digital 3-D and potentially 4-D models within the next 5 years. The agency typically used 3-D modeling for specific projects that involved complex scope and the building of reinforced structures and for projects located in highly urbanized areas with high traffic volumes. Ohio DOT reported being in the process of improving its visualization and modeling tech- nologies so that a high level of detail could be provided for a structure (e.g., bridges, barrier walls, guardrails, and drainage structures), but presented in a way that it was easy to follow and use for both Ohio DOT staff and contractorsâ staffs. Once a project was under construction, agency inspectors would have a mobile device in the field that would geolocate the inspector within the proximities of the project and allow a more accurate inspection. For each location, the inspec- tor would annotate specific aspects or components of a project in the model that would then be recorded into a database via a cloud server. Once the information was entered, the program would automatically flag any noted discrepancies. DOT staff mentioned that a project along I-71 in Grove City, south of Columbus, used a 3-D model for major portions of the work. This $40+ million project, part of FHWAâs EDC-3 initiative, included major pavement rehabilitation of I-71 from SR-665 to Stringtown Road. Using local consultants, Ohio DOT created and delivered a 3-D model, which included electronic deliverables such as 3-D triangles, 3-D linestrings, LandXML alignments and surfaces, and all computer-aided design and drafting files, to the contractors bidding on the project. Contractu- ally, the department included the 3-D model for earthwork, pavement work, and maintenance of traffic. Contractors then used the model to develop a proposal that included the critical path method schedule to show when traffic control would be needed, when the contractors would plan to bill for pavement work, and when the contractors would plan to finish the earthwork tasks. So that contractors could use the 3-D model, Ohio DOT developed and supported the quantities in the 3-D model, and all quantities in the 3-D model superseded the quantities shown in the 2-D plans. DOT staff reported that the data and information provided to the winning contractor for the I-71 project was more than needed. The department anticipated time savings with the use of the model on the I-71 project, but the contractor stated that extra time cleaning and organiz- ing the data was not worth the extra effort. Furthermore, the department planned to develop a 4-D model to include the time component of the project. However, Ohio DOT and the contrac- tor were unable to find a suitable software program for producing a 4-D model for a horizontal infrastructure project. Ohio DOT noted that more software options for vertical construction projects were available than for horizontal highway construction projects. Ohio DOT was concerned with the incompatibility of software and hardware for visualiza- tion and modeling. The department used a specific brand of software for visualizations and modeling, but the contractors that worked with Ohio DOT used a variety of other software products. DOT staff said that they provided files from which a contractor could use the model- ing information to recreate the model in their software systems. However, staff anticipated a move toward providing more usable models to the contractors so that contractors would not have to recreate the model. Interconnected Technologies Three-D modeling allowed for development of AMG for use with earthmoving and paving equipment. These projects included grade specifications provided by Ohio DOT to the contractor. The contractor then could choose, on the basis of means and methods, to use connected equipment based on the specifications and the information provided for the AMG.
52 Emerging Technologies for Construction Delivery The I-71 Grove City project successfully used AMG for earthwork and paving operations during construction. Safety Technologies Safety was a concern for the Ohio DOT; protecting the lives of workers and motorists in a construction work zone was always a priority. The use of technologies in work zones provided safer working and traveling conditions, as more useful information was provided to motorists and workers. For highway projects, the DOT allowed contractors to use their means and methods to apply safety technologies at their discretion as long as the depart- ment approved them. Also, the agency could choose to include various safety technologies as part of the project specifications. When Ohio DOT included a specification for safety technology in the project documents, the contractor included it in its costs as part of executing the contract. Some of the safety technologies used for construction safety included mobile DMS, VSL zones, and queue detection. The DMS system allowed Ohio DOT to broadcast traffic and conges- tion information for motorists approaching a construction work zone. VSL zones were used by assigning predetermined speed limits based on worker presence, positive protection in use, work zone conditions, and the original speed limit for that section of roadway. Ohio DOT used two variations of queue detection warning systems for projects that had either recurring congestion or in situations when slowing or stopping traffic in a work zone could surprise motorists, such as coming over a hill or an embanked turn. The department also collected traffic information in work zones and was involved with an FHWA initiative to use the data to improve safety in work zones. Instrumentation and Sensors Instrumentation technologies provided Ohio DOT and its contractors more accurate and less invasive devices to allow for better measurements for specifications and project perfor- mance measures. The department ran several demonstration projects for instrumentation technologies, including thermal profiling, measuring environmental conditions, density mea- sures, radiographic weld checking, and infrared sensors to measure the placement of rebar in a structure. The use of these technologies was intended to gain better measurements for QA/QC purposes and to conduct inspection tests that were nondestructive and more accurate and to collect much more data for analysis. Unmanned Aircraft Systems In 2015, Ohio DOT began exploring the use of UASs for various activities, including specific construction tasks. The UAS program promoted UAVs and the associated system technologies for the entire state of Ohio and did not necessarily focus on construction, surveying, and mapping. The UAS program focused more on the actual UAVs and equipment and on the rules and regulations for flying a UAV. However, within the design and construction divisions of Ohio DOT, staff were investigating cameras, surveying and mapping tools, and navigation systems on board a UAV along with the software for postprocessing the collected data. Contrac- tors working with the department were using UASs for various construction tasks, including site mapping, and monitoring work progress, but the contractors used these data for internal purposes and did not typically share this information with Ohio DOT. Agency staff mentioned that the department had not determined potential benefits from using UASs for construction regarding accuracy and the automation system aboard the UAV. Various
Case Examples Using Technologies for Construction Delivery 53 types of UAVs have different types of equipment on board, and without testing all these different variations, Ohio DOT had difficulty in understanding the actual value of implementing UASs for construction. However, Ohio DOT staff mentioned some testing occurred with UASs for construction inspection purposes at locations that were difficult or unsafe for a person to access. Lessons Learned Based on the discussions with Ohio DOT staff, lessons learned from using technologies for construction delivery include the following: â¢ Championing of the use of technology. The department reported that for a 3-D model of a highway project to be worthwhile and useful for a contractor, Ohio DOT had to support its use and stand behind it just as it would with a 2-D design. â¢ Lack of developed technologies. Ohio DOT indicated that 3-D modeling had more immediate value than 4-D models. The intent with the EDC-3 was to use 3-D models and to incorpo- rate the time component to create the 4-D model. However, the Ohio agency reported that 4-D modeling software for infrastructure projects was not at the level that it needed and put this process on hold until improvements in the software packages were available for highway infrastructure construction. â¢ Performance specifications for the use of technologies. Ohio DOT reported that the use of performance specifications provided contractors flexibility in the use of technologies for con- struction and that contractors were perceived as more advanced in the use of technologies than the department. Contractors wanted to use technologies on Ohio DOT projects as they realized the benefits of their use, and the department encouraged technology use with the inclusion of performance specifications in the contract documents. â¢ Technologies making construction delivery more efficient. Ohio DOT realized that advanced technologies provided a way for human resources to be more efficient; improved efficiency resulted in better accuracy and effective management of worker-hours. The department indi- cated that efficiently managing project personnel allowed the completion of more activities and projects. Pennsylvania Department of Transportation The Pennsylvania DOT is responsible for construction and maintenance of approximately 50,000 centerline miles of Interstate and state highways, which includes 24,000 bridges through- out the state. On an annual basis, the DOT constructs about 800 projects, utilizing $2.4 billion of the annual DOT budget. Because of the size and volume of traffic that moved along Penn- sylvania roadways, Pennsylvania DOT noted the need to operate as efficiently as possible to construct critical highway projects throughout the state. In an effort to improve efficiencies and use the resources available, the DOT used technologies in the areas of 3-D modeling, interconnected equipment for earthwork and paving, advanced safety technology warning systems, and various instrumentation and sensor devices and was exploring the use of UASs. Table 20 outlines the types of technologies used on the departmentâs highway construction projects. Use of Technologies for Construction Delivery Pennsylvania DOT staff mentioned that one of the driving forces behind the inception of technologies for construction delivery was a champion within the department who could lead the efforts in educating and using the technology. Several years earlier, a district executive
54 Emerging Technologies for Construction Delivery at the department saw an opportunity to use more technologies for construction and super- vised a staff wanting to use technologies in their positions. At first, Pennsylvania DOT used SharePoint to route document reviews between the various DOT units, the contractor, and the design team. After experiencing success in sharing information electronically, the agency had several app-based tools that field and design personnel could use for many areas of work, including design, construction, and maintenance and operations. The information technology team at Pennsylvania DOT continuously developed various apps as requested by internal staff who would like an app that could perform a function electronically and eliminate paper-based documents and processes. Before a technology became a mainstay, the implementation of new technologies at Pennsyl- vania DOT was for a one-off or a specific situation in which the department would gauge the value of a technology. On large projects, greater than $100 million in scope, Pennsylvania DOT allowed the use of technology tools to help overcome the vast and complex nature of the projects and to be more accurate and efficient in putting work in place. Visualization and Modeling Pennsylvania DOT envisioned that projects with large scopes of work would justify the use of 3-D modeling. However, staff reported that they developed only a few models mainly for proj- ects with large earthwork quantities in the previous 2 years. When the department developed a 3-D model for a project, it provided the 3-D model as reference documentation for contractors. Contractors used the 3-D model for estimating quantities for bidding purposes and for tracking the progress during construction. The more sophisticated contractors took the model data from the DOT and developed their own model that provided contractors with more of the means and methods details that pertained to the actual construction work. With the development of 3-D construction design models, Pennsylvania DOT investigated the legal implications of moving from traditional 2-D plans to 3-D models as part of the contract documents. One issue related to the contractual repercussions when a model had an incorrect quantity or error shown. The DOT initially wanted to add a disclaimer to the 3-D model to use at the contractorâs own risk, but DOT lawyers cautioned that if a Pennsylvania DOT 3-D model Technology Types Uses Visualization and modeling â¢ Building information modeling LiDAR â¢ Constructability reviews â¢ As-built documentation â¢ Verification of completed work Interconnected technologies â¢ Haul vehicles â¢ Earthwork equipment â¢ Paving equipment â¢ AMG â¢ e-ticketing Safety technologies â¢ Proximity warning alarms â¢ DMSs â¢ Queue detection system â¢ Accident avoidance â¢ WZI for motorists â¢ Removing workers from harmâs way Enhanced protection for workers â¢ Work zone traffic control Instrumentation and sensors â¢ Audio/video/CCTV â¢ Remote sensing â¢ Specification measurement sensors â¢ Recording of placement of work â¢ Identification ofoptimal work conditions â¢ QA/QC â¢ Construction inspections UASs â¢ Monitoring progress of work â¢ Material inventory â¢ Construction site security â¢ â¢ Table 20. Technology types and uses for Pennsylvania DOT projects.
Case Examples Using Technologies for Construction Delivery 55 contained an error, then the department needed to admit the error to the contractor and to cor- rect it in the model. Further, the DOT realized that the design team for a project needed to be more diligent with the development of the 3-D model and to understand how this model was to be used during construction. Overall, Pennsylvania DOT was moving toward the use of 3-D models for most projects, as the models became part of the contract documents, and thus moving away from the less detailed 2-D plans. In its current form, once a project with a 3-D model was let for bidding, the model was then a part of the bid package to interested contractors. During the procurement phase, the 3-D model contained locked and hidden elements so that the bidding firms could not make any changes. When awarding the project, the department provided the contractor with an unlocked version of the 3-D model and allowed the contractor to use the model for whatever purpose they wished. Pennsylvania DOT mentioned instances in which contractors used 3-D models for construction including detailing quantities, AMG for paving and earthwork equipment, investi- gating potential constructability issues before performing the work and simulating various crane setups and milling operations. Interconnected Technologies As a part of its paving operations, Pennsylvania DOT, taking cues from several nearby DOTs already using this technology, experimented with e-ticketing for asphalt paving. Although Pennsylvania DOT saw potential in the e-ticketing system, the results in piloting this technol- ogy were fewer than anticipated. In an instance described by staff, the primary issue that the contractor noticed on one of the first e-ticketing pilot projects was that the contractor had to bring in a second person to monitor the individual who was collecting the e-ticketing informa- tion in the field with an iPad. The project manager noticed that the individual with the iPad was not paying attention to the heavy vehicles and equipment traveling nearby. To protect this person, a second person was needed, which made the situation less efficient. However, the agency noted that pilot testing was performed so that issues such as this were solved before full implementation. Another area using connected equipment was trenching and trench safety. Pennsylvania DOT used remote-controlled trench compactors (see Figure 28), pump roller machines about the size of a small compact car. The compactor uses a pump that varies the pressure Figure 28. Remote controlled trench compactor (ForConstructionPros.com 2018).
56 Emerging Technologies for Construction Delivery applied to the surface, which a person controls with a remote control outside of the actual trench. The compactor travels the length of the trench to compact a lift, then moves out of the way to allow earthwork equipment to add more material, and the compactor travels the length of the trench again compacting that lift. The process repeats itself until the correct level and compaction are achieved. The ideal situation when using remote-controlled trench compactors exists as one person can control the machine without entering the trench and thus is out of harmâs way. Safety Technologies Many safety technologies were used by Pennsylvania DOT. Most projectsâexcept small projects with low traffic volumesâused some, if not all, of these technologies. The safety technologies of interest at the DOT were queue detection and proximity safety systems. Pennsyl- vania DOT had a few units of a proprietary queue detection and intrusion alarm system; to test. The devices were attached to equipment surrounding a work zone and which linked wirelessly to a small vibrating device attached to worker safety vests. If something triggered the deviceâ something had intruded the work zone geofence inadvertentlyâthe device sent a signal to the workersâ device, which then vibrated to indicate that the workers needed to leave the area imme- diately. This system was based on a U.S. defense proximity system, but was a proprietary system; its use was therefore limited. However, as technologies continue to advance, Pennsylvania DOT will consider queue and intrusion detection systems as it sees significant potential in the use of these safety systems for construction work zones. Instrumentation and Sensors Pennsylvania DOT staff noted that they distributed tablets to field personnel to use during construction of a project and to access the apps that the department developed to assist with the construction and inspection process. The tablet devices contained either various apps that Pennsylvania DOT had developed or apps from third-party developers that the department had tested and verified. One such app that helped with pile installation and inspection could measure the ringing frequency of a pile hammer as it hit a pile to indicate the pile depth. The app provided accurate measurements and showed potential for further use. Pennsylvania DOT developed another app to conduct construction inspections electronically. The app, called MCDocs, pro- vided construction and contract documents electronically in the app for review during inspec- tion. Then, the inspector recorded the inspection report in the app; once an inspection was complete, the inspector submitted the report electronically. Pennsylvania DOT also used instrumentation for specific situations. In one instance cited by DOT staff, the department used a handheld weather station device to collect climate conditions for bridge deck pouring activities. The handheld device could measure the current humidity level and wind speed to make sure that the proper range was adhered to before placing the deck. Essentially, the tool helped determine the evaporation rate of the concrete mixture so that the contractor would know if it could safely place the deck and cover it without compromising the surface integrity of the pavement. With the move to the use of tablets in the field, Pennsylvania DOT had an app to create an electronic heat sticker with a barcode for inspection samples. The sticker contained project and sample information. The sticker was printed from a printer connected wirelessly to a field tablet and then affixed to the sample and sent in for testing. The tablet devices helped to eliminate unnecessary paper documents and provided the sample identification information in a server so that project personnel could access it more efficiently than tracking down a hard copy of the document.
Case Examples Using Technologies for Construction Delivery 57 Also for construction inspections, Pennsylvania DOT allowed contractors to use non- destructive tests for quality control in measuring the concrete pavement thickness. Once con- crete was paved over a washed metal plate placed on the subbase, a ground-penetrating radar device could measure the thickness by using magnetic waves. This information was a DOT specification for concrete paving projects, but contractors were not readily using this method, as the department commonly utilized concrete core cylinder tests for quality acceptance purposes and contractors tended to use the more traditional core sampling process. Unmanned Aircraft Systems Pennsylvania DOT had not fully embraced the use of UASs for construction purposes. There were internal concerns that dialing in the accuracy of a UAS was much more difficult than previ- ously thought. The department believed that advanced ground-based surveying technologies could produce the same, if not better, accuracy without the need to deal with strict FAA rules and regula- tions. Pennsylvania DOTâs policy about UAS usage to comply with FAA rules, regulations, and plans was in the works, along with plans to explore more possibilities of using UASs for construction. Although Pennsylvania DOTâs UAS usage for construction purposes is limited, the depart- ment allowed contractors to use UASs, which they did on large and complex projects for generating quantities and cost estimations. However, an issue existed in documenting quanti- ties; Pennsylvania DOT required a conventional survey for final quantities and did not accept quantity values collected with an UAV with surveying equipment. Therefore, the contractorâs use of UASs was mainly for internal purposes only. As for the potential value of UASs for construction, Pennsylvania DOT staff presented an example situation: a recent bridge rehabilitation project that had a nest of endangered birds liv- ing in the bridge abutments. Accessing this area of the bridge was extremely difficult, so the DOT flew a UAV with attached camera and video equipment to the nest location under the bridge to see if the birds were there and if the eggs had hatched. Field personnel would fly the location once in the morning and once in the afternoon; if the all-clear were given, work would continue. Once the birds returned to the nest and the eggs began to hatch, work was halted until further notice. The use of a UAV with communication and camera equipment simplified the process. Lessons Learned On the basis of discussions and investigation of Pennsylvania DOT, lessons learned as reported by staff include the folowing: â¢ Leadership to champion the use of technology. The DOT indicated that without someone to lead the efforts in the use of a technology, the technology may not advance to implementation and use on construction projects. Many technologies discussed here are a result of champions leading the efforts at Pennsylvania DOT. â¢ Having the right people use a technology. Pennsylvania DOT reported that having individu- als comfortable working with technology made a big difference in understanding and gaining the full value of the technology. If users cannot establish a comfort level, they then do not see the need to change a process or procedure that works in its current state. Once establishing a comfort level, people are more willing to change their processes and procedures and are more willing to allow the use of technologies by contractors. â¢ The business case for using technology. Pennsylvania DOT considered and experimented with many technologies, but to move a technology into regular practice, the department needed to demonstrate its value and potential for large-scale deployment. Pennsylvania DOT continued to use and explore innovative technologies and was strategic in its testing and implementation decisions.
58 Emerging Technologies for Construction Delivery Utah Department of Transportation The Utah DOT is responsible for construction and maintenance of more than 6,000 centerline miles of roadways throughout the state. Utah DOT annually constructs more than 150 projects, with a capital budget of approximately $1 billion. To minimize impacts to the traveling public and the economy, Utah DOT employed various technologies to deliver highway construction projects. The types and uses of technologies at the department, shown in Table 21, varied in their use and maturity. Most technologies had been initiated within the past 10 years, with some in the pilot or assessment phase. Use of Technologies for Construction Delivery The Utah DOT employed technologies during project delivery to improve efficiency. The department consistently looked for ways to make agency staff, consultants, contractors, and inspectors more efficient. Greater efficiency translates to the ability to perform more work with available funds. Improvement was therefore critical to Utah DOT as staff mentioned that the workforce remained constant while the transportation system and associated work increased. The DOT saw the use of new technologies as a way to meet increasing demands while reducing costs and increasing efficiency. Many technologies resulted from collaboration between Utah DOT and the consulting and contracting communities. For example, contractors using AMG for paving approached the department to discuss the transfer of information. Contractors knew that UDOT was creat- ing 2-D plans for a project from a 3-D model and asked if Utah DOT could provide the model as a starting point for contractors to create their own 3-D model. As stated by Utah DOT staff, implementing model-based design and construction with the digital transfer of information had the potential to produce a more optimal design and to improve information transfer, decision- making, and efficiency. Technology Types Uses Visualization and modeling â¢ Building information modeling LiDAR â¢ Constructability reviews â¢ Simulation of bridge construction â¢ Location of utilities â¢ Verification of work completed â¢ Virtual design and construction â¢ Construction inspections Interconnected technologies â¢ Earthwork equipment â¢ Paving equipment â¢ AMG â¢ Location of vehicles Safety technologies â¢ DMSs â¢ VSLs â¢ Dynamic lane merging â¢ Incident tracking and analysis â¢ Work zone traffic control Instrumentation and sensors â¢ Audio/video/CCTV â¢ Remote sensing â¢ Specification measurement sensors â¢ Maturity meters for concrete strength â¢ Real-time traffic information â¢ Monitoring of progress of work â¢ Verification of design during construction â¢ Location of utilities â¢ Construction inspections UASs â¢ Fixed wing â¢ Multirotor â¢ Hybrid â¢ Monitoring of progress of work â¢ Construction documentation â¢ Construction surveying â¢ Site mapping â¢ Material inventory â¢ Construction inspections â¢ Table 21. Technology types and uses for Utah DOT projects.
Case Examples Using Technologies for Construction Delivery 59 Another example of Utah DOT collaborating with contractors and the traveling public is the use of VSL in the work zone. A consistent message from the contracting community was the need to slow down traffic in work zones. Conversely, Utah DOT received consistent complaints from the traveling public about work zones with reduced speeds, but no work occurring. There- fore, Utah DOT staff noted that the use of VSL resulted in an improved reduction in speed when workers were present in the work zone and the ability to adjust speeds accordingly when workers were not present appeased traveling motorists. Visualization and Modeling An early complication that the department encountered early in moving toward the use of 3-D models was how to handle the legal risk of the models being changed once they were delivered to contractors. Therefore, staff mentioned that they took steps to lock elements and functions in the software and models so that changes were not made without being noticed in the model. Similar to electronic Adobe documents, a change or modification in a contract document model negates the certification and stamp. With this precaution in place, Utah DOT advertised several projects for bid using 3-D models and the digital transfer of information. By establishing processes and procedures around digital project delivery, Utah DOT realized that it could mitigate legal risk concerns. Another challenge was that not all contractors could use 3-D models and other technologies associated with the models such as AMG and surveying techniques. As Utah DOT moved toward a digital project delivery environment, the lack of understanding by some contractors could impede the full implementation of 3-D models. Many of the larger contractors were already supporting the direction, and in the case of design-builders, the teams already had staff engineers who were versed in the use of modeling technologies. The smaller contractors were not as sophisticated and might lack the skills, expertise, and associated staff to use this type of technology appropriately. Utah DOT staff understood this situation and planned to take steps to help educate all contractors on the 3-D model workflow process. Further, Utah DOT provided support and training to designers and contractors to help educate the industry in the develop- ment and use of modeling technologies. Interconnected Technologies The construction industry in Utah used AMG for paving and earthwork operations for projects that exceeded $5 million. Utah DOT used performance specifications that allowed the contractor the discretion on what means and methods or technologies to use to complete a proj- ect. AMG for earthwork was commonplace and aided the contractor in controlling grade as well as improving efficiency. AMG for paving became more mainstream for large operations because it solved some of the challenges presented by a string line, such as (1) the need to drive supply trucks around a string line in increasingly narrower work zones, (2) errors when string lines were âbumpedâ by workers, and (3) interference of the string line in finishing operations. Though increasingly mainstream, the next phase of AMG was for Utah DOT to deliver the project 3-D model as part of the contractual documents and potentially to be able to retrieve AMG data for contractorâs earthwork and paving operations. Safety Technologies Utah DOTâs primary focus on safety for all activities meant that the agency adhered to continuous safety monitoring for construction work zones. The use of safety technologies provided the DOT with an advanced level of protection for the workers and traveling public on roadways across the state. Although the contractor was responsible for keeping work zones
60 Emerging Technologies for Construction Delivery safe, Utah DOT worked with contractors to pilot the use of advanced safety technologies that showed promise. VSL was one of the work zone safety technologies mentioned by Utah DOT staff. VSL are portable and adjustable speed limit signs to lower and adjust the speed limit within a work zone. Commonly, contractors reduce the speed limit at the project limits even though work may be occurring only in a small portion of a work zone. Utah DOT found that the public was generally understanding of reduced speed and delay if they observed work occurring. VSL was used where work was occurring and reduced the speed limit only for that area. This approach, as reported by Utah DOT staff, resulted in a greater reduction in speed than in work zones not using VSL. Another safety technology used on about 25% of Utah DOT highway projects was portable rumble strips. The DOT identified manufacturers of portable rumble strips that provided a product that performed well and developed suitable specifications. Utah DOT noticed that por- table rumble strips helped to slow down traffic when approaching a work zone and that the rumble strips could be removed easily when the work zone was unoccupied so that motorists could travel through without delay. Instrumentation and Sensors Utah DOT used remote cameras at project sites to document the progress of work. Further, the DOT used sensors and testing instrumentation to measure the placement of work to com- pare it to the project specifications. Utah DOT was also discussing the application of sensors on certain equipment to measure conditions during placement of work. Contractors used sensors to measure the temperature at the rear of a paving machine and then used density-tracking sensors to monitor the roller and track the compaction quality. Utah DOT was also using real-time traffic information to maximize the construction window available for the contractor. Typically, traffic engineers studied historical data to determine the appropriate time to close lanes of traffic; the data, for contractual purposes, were typically con- servative. DOT staff indicated that they were using probe vehicle data and data from deployed sensors near the work zone to monitor real travel times and delays. The technology could be programmed to alert Utah DOT crews and the contractor of the proximity to threshold delay conditions, which could guide contractors as to when traffic control removal needed to begin. Further, on the basis of the data, work windows could be increased to maximize the efficiency of construction crews. Using the 3-D model for construction presented many opportunities. Utah DOT was work- ing with technologies that allowed inspectors to visualize the model in the field by using virtual reality equipment (such as a phone display). This technology allowed crews to see conflicts not noticed during design or to verify that the constructed elements were in accordance with the model. In addition, using the 3-D model presented the opportunity to attach conformance information directly to the element. Unmanned Aircraft Systems Utah DOT formalized its UAS program in 2016 by establishing a policy, procedures, training, and resources to support the program. Examples of uses for Utah DOT include but are not limited to, aerial photography, photogrammetry, bridge inspections, geotechnical field investigations, LiDAR applications, public outreach, mapping construction sites and conditions, asset management and inspections, traffic monitoring and incident management, disaster response, and training exercises. As mentioned by the DOT staff, the use of UASs could provide cost efficiency, improve data quality, and increase worker safety when compared to existing processes. As an example, in the
Case Examples Using Technologies for Construction Delivery 61 use of UASs for construction surveying, Utah DOT staff noted productivity increases, especially for projects in rural and limited access areas in southern Utah. Surveying activities that had required months to complete now took about a week to collect and process the data and sub- stantially reduced the time needed to survey a project site. One of the advancements at Utah DOT was the ability of a UAV equipped with survey tools to provide accurate and detailed land surveys, which were then incorporated into a projectâs 3-D model. Utah DOT combined some of the more traditional surveying and ground-based LiDAR photogrammetry processes with data collected from UASs to map the layout of a project site with precise and accurate measurements that represented the actual conditions of the project before, during, and after construction. The more accurate the 3-D model was, the better estimates that Utah DOT obtained from contractors. Further, collecting the same data with UASs at the end of a project provided the department with a living as-built document. As the technology continued to evolve, Utah DOT staff expected to make project 3-D models even more accurate. The department also used UASs for measuring stockpiles of materials on project sites and planned to measure the volume of cut and fill before constructing the project. Utah DOT would like to use UASs to measure quantities more accurately and rapidly over larger areas. The DOT also allowed and encouraged contractors to use UASs for means and methods during construc- tion. The ability to fly over a site and collect data improved the inspection process and made project data more accurate. Inspectors with a RTK rover instrumentation device could check the placement of work, especially in areas that were difficult or unsafe to reach. Data collected from the contractorâs UAV flight and information from inspectors were compared to the 3-D model to verify work and to make progress payments based on precise quantities. According to Utah DOT staff, this process resulted in approximately 2% cost savings to projects and reduced the number of worker-hours needed to inspect projects. Lessons Learned On the basis of discussions and investigation of Utah DOT, lessons learned from using emerg- ing technologies for construction delivery that the DOT reported follow: â¢ Support from contractors and DOT senior leadership. Having support from the contracting community and upper management at the DOT substantially helped to move a technology into practice. As stated by Utah DOT staff, many times contractors would approach Utah DOT and request the use of a technology. The DOT encouraged collaboration to improve processes and become more efficient. â¢ Contractual use of technologies. The legal aspects of incorporating technologies into the contract documents can be a challenge. Utah DOT reported that understanding the con- tract requirements along with defining distinct roles and responsibilities needed to be clearly communicated. â¢ Contractors lack the knowledge to use technologies. Some of the smaller local contractors may not possess the necessary technical knowledge and expertise to use such technologies. Therefore, UDOT provided technology support to contractors, fabricators, and suppliers. UDOT recognized that to implement a digital delivery of projects, all contractors would need to support the direction and be able to use the technologies. Washington State Department of Transportation The Washington State DOT constructs and maintains more than 18,000 lane miles of high- ways, including 3,300 bridge structures. Construction of highway projects at Washington State DOT annually includes more than 150 projects, using a capital budget close to $1 billion. As a
62 Emerging Technologies for Construction Delivery part of the agencyâs strategic plan, Washington State DOT had six core values of safety, engage- ment, innovation, integrity, leadership, and sustainability. The use of emerging technologies for construction delivery enhanced these values and made the use of technologies critical to the business operations. Table 22 outlines the types and uses of technologies utilized by Washington State DOT for construction delivery. Use of Technologies for Construction Delivery As discussed with Washington State DOT staff, the driving force behind the implemen- tation of technologies for construction delivery was a result of the collaboration with the contractors and consultants that worked with the DOT. Washington State DOT had a close working relationship with the state Associated General Contractors groups; during meetings with the roadways and structures groups, the discussion commonly focused on how the use of emerging technologies was made a part of the contract documents. Thus, the idea of using a technology came from a contractor on a specific project. The contractor may have had the equipment ready to use the technology, and the contractor then approached the Washington State DOT project manager about using that technology for the project. In most cases, the DOT was open to the use of technologies during construction to help contractors with means and methods. However, the use of technologies was not to be an additional cost to the depart- ment, and the contractors still needed to meet the contract requirements regardless of how they performed the work. A critical aspect of implementing the use of a technology was that it served a purpose in solv- ing a problem or making a process more efficient. DOT staff mentioned that they had many demonstrations for various technologies recently, and although the technology looked attrac- tive, if there was not a business case to solve a genuine issue, then that technology did not have enough value for implementation. For successful implementation of a new technology, Washington State DOT realized that early investment was significant in getting the most out of the technology. However, finding the Technology Types Uses Visualization and modeling â¢ Building information modeling LiDAR â¢ Constructability reviews â¢ Public communication Interconnected technologies â¢ NA â¢ NA Safety technologies â¢ Proximity warning alarms â¢ WZIA â¢ DMSs â¢ VSLs â¢ Health monitoring equipment â¢ Moveable concrete barriers â¢ Accident avoidance â¢ WZI detection â¢ Work zone information for motorists â¢ Removal of workers from harmâs way â¢ Incident tracking and analysis â¢ Work zone traffic control Instrumentation and sensors â¢ Audio/video/CCTV â¢ Remote sensing â¢ Structural integrity sensors â¢ Environmental conditions sensors â¢ Specification measurement sensors â¢ Infrared sensors â¢ Monitoring of progress of work â¢ Evaluation of structural members â¢ Verification of design during construction â¢ Location of utilities â¢ QA/QC â¢ Construction inspections UASs â¢ Construction documentation â¢ Site mapping â¢ Table 22. Technology types and uses for Washington State DOT projects.
Case Examples Using Technologies for Construction Delivery 63 right conditions to initiate the investment was a hurdle that included acquiring the technology, learning about it, testing it, implementing it, and assessing the benefits. As an example, moving toward the increased use of automated equipment and machinery was beneficial to contractors so that they were more efficient and accurate in the placement of work, but the initial investment in automated equipment could be quite high. A common barrier was the resistance from employees to change current processes and pro- cedures. The difficulty lay in the ability to get DOT employees to recognize the value of imple- menting a technology that potentially revised a particular aspect of a project from a traditional process to one that involved a new technological approach. The high turnover that Washington State DOT experienced in some positions complicated the acceptance process of implementing new technologies in the organization. Visualization and Modeling The Visual Engineering Resource Group (VERG) within Washington State DOT developed 3-D models, simulations, videos, and other graphical systems to provide clear and effective com- munication of a projectâs development, design, and construction. VERG used 3-D visualizations to explain complex design options, construction processes, or context-sensitive solutions to stakeholders such as the traveling public. VERG then used animation to simulate the construc- tion and use of a project to visualize what the process or final product might look like. VERG also handled the development of videos such as historical documentation and safety videos and was a part of the DOTâs development of its UAS program. VERG acted as the liaison between Washington State DOT and a third-party commercial UAS operator. Overall, VERG assisted the construction delivery process by providing a visual representation of projects that helped the public and legislature to understand the project in the planning stage and under construction. Washington State DOT was in a research and development phase as it pertained to using 3-D models for construction documents. One aspect in development was adding smart elements to 3-D models, including detailed information about various components of a project. These elements included design and specification information along with updated information during construction to create a 3-D as-built model of the project. As explained by the DOT staff, one could hover over a component, such as a catch basin shown in a model, and information would pop up to show who designed it and how, the specifications used, and any special notes about the element. Staff reported that they develop 3-D models for earthwork and paving construction projects using InRoads and that the DOT provided extensive training to the design and construction employees in the use of modeling software. When Washington State DOT created a model for a project, the agency provided the model to the contractor, but the model was not a contract document and contractors used it at their discretion. A barrier to moving forward with 3-D models as contract documents was the legality of the 3-D model. A stamped 2-D contractual set of construction plans dictated decisions for resolving issues, but Washington State DOT staff mentioned that they were struggling to figure out how to transition to a digital document that still protected the sanctity of the engineerâs stamp. The DOT would like to move toward using 3-D models instead of 2-D plans as contractual documents, but there was no established timeline for accomplishing this goal. Safety Technologies Safety is one of the core values of the Washington State DOT; keeping workers and motorists safe is always a primary concern. As a result, the department occasionally included specifications for the use of VSL on projects in high-traffic and congestion areas. The specifications provide
64 Emerging Technologies for Construction Delivery direction to the contractor on the length, duration, and speed for the work zone. Further, the DOT had used WZIA, but it was not a tool regularly used. The intrusion system used an audio device attached to a cone so that when an object contacted or tipped over the cone, a loud audi- ble sound was transmitted and anyone within close proximity knew to take protective measures. However, Washington State DOT experienced limited benefits from this relatively low-tech system, and therefore the tool was not used often. Additionally, staff said that some low-tech safety solutions did not prove as valuable as the department had initially thought. Washington State DOT was working with more advanced ITS safety technologies, such as queue detection, dynamic lane merge, and ITS traffic management. Washington State DOT used queue detection systems and dynamic lane merge systems for traffic awareness in work zones, which have proved to be valuable and useful safety tools. The queue detection system involved a portable device that used a wave detector that sensed changes in traffic flow; an alert was then transmitted on a DMS to warn motorists approaching the work zone of an impending slowdown or backup of traffic. Dynamic lane merging uses the queue detection system along with flashing beacons and no passing signs to operate a no-passing zone in an active work area that moves in conjunction with the lane closure queue. Both systems showed potential, and the department planned to continue their use. Instrumentation and Sensors A significant change in the inspection process at Washington State DOT resulted from using tablet devices in the field. The tablet devices allowed inspectors to collect more information and to have easy access to other project information. The use of the tablets allowed inspectors to be more efficient and to inspect more aspects of the project in greater detail compared to traditional inspection methods. Pertaining to work zone safety, Washington State DOT used instrumentation to monitor air quality and noise levels for field workers. The DOT stated that work zones were to be as safe as possible regarding protecting workers and traveling motorists. To enhance hearing protection, the department used audio detection devices to measure the audio level at a site and warned workers when the sound could be damaging to oneâs hearing. For projects that might have included air quality issues, Washington State DOT used environmental air quality sensors to warn workers of situations when air quality was less than acceptable. The DOT was pilot testing the use of instrumentation to measure concrete pavement depths. Before a section of a roadway was paved, a metal plate was placed on the subbase layer. Once the concrete pavement was poured over the metal plate, a ground-penetrating radar device could measure the concrete depth by bouncing waves off the metal plate and back to the device. For asphalt paving, Washington State DOT was experimenting with the use of a trolley-like system that measured the in-place density of hot mix asphalt. The trolley system allowed contractors to measure the density of the entire roadway with ground-penetrating radar and infrared sensors, which improved the quality of the placed pavement. In both cases, Washington State DOT was looking for ways to use technology to reduce the use of destructive testing, but the drawback to these two instrumentation measurement systems was the expense. Unmanned Aircraft Systems The Geotechnical Division used UAVs equipped with LiDAR the most, but not on a regular basis, to check slopes, slides, and rock movements around roadways. UAS use for geotechnical investiga- tions was beneficial as some of these slide and rock crawl areas were difficult or unsafe to access with a vehicle or on foot. However, for construction, Washington State DOT did not determine what problems a UAS could solve strategically, as traditional methods of surveying and site layout were
Case Examples Using Technologies for Construction Delivery 65 acceptable forms of means and methods to complete a project. The DOT eventually wanted to use UAVs for internal surveying purposes, but did not yet determine the optimal approach to accom- plish this goal. Further, Washington State DOT may have looked to use performance specifications to include UAS work for the contractor as it made more sense for contractors to maintain a fleet of UAVs and the associated equipment and system rather than the DOT doing so. Furthermore, Washington State DOT staff reported that the contractors were the parties on a project that used UASs during construction. Contractors working on Washington State DOT projects flew UAVs to collect project information for communication purposes to project stake- holders and the public. Contractors flew a site to collect data on a different angle or perspective of the work performed. This process was apparent in the DOT designâbuild highway projects in which the contractor had a contractual responsibility to communicate project information to the public during construction. Lessons Learned On the basis of discussions and investigation of Washington State DOT, lessons learned from using emerging technologies for construction delivery follow: â¢ Early support and investment. Washington State DOT stated that early support and invest- ment were critical to the development and implementation of a technology for construction. Once the DOT determined the benefit of a technology and envisioned the potential in the long run, the right situation had to be determined to initiate early investment and implementation. â¢ Communicate the use of technologies to DOT staff. Washington State DOT reported that communicating and gaining buy-in from users of the technologies was critical. Clearly com- municating the change in the process related to the use of new technology and offering train- ing helped users be more receptive to technological implementation. â¢ Technology providing a solution to a known problem. The DOT reported that the agency needed a technology to truly assist or solve a current problem and not a technology that was a solution looking for a problem. Although many technologies looked appealing, unless the technology solved a known problem, it might not possess enough value to warrant its use. Wisconsin Department of Transportation The Wisconsin DOT constructs and maintains more than 12,000 centerline miles of state, federal, and Interstate highways throughout the state. As for construction, Wisconsin DOT annually per- forms around 350 capital improvement projects with a budget of more than $1 billion. Wisconsin DOT was shifting from a typical construct and maintain approach to a more preservation-minded approach, that is, more work in terms of taking care of and preserving the current transportation highway infrastructure and less reconstruction work. Further, one of the DOTâs core values was improvement, which focused on finding innovative ways to provide better products and services. With that in mind, technologies played a critical role in understanding the preservation needed for a facility and how to go about preserving the facility appropriately and documenting it digitally for future use. Table 23 outlines the types and uses of technologies at Wisconsin DOT. Use of Technologies for Construction Delivery Many of the innovative technologies in use at Wisconsin DOT resulted from pilot tests of the technology before full-scale implementation and from an understanding of the complemen- tary nature with other technologies. Visualization and modeling technologies provided details to contractors for AMG for earthwork and paving equipment. When inspecting pavement installed using stringless paving and interconnected equipment, inspectors were provided with
66 Emerging Technologies for Construction Delivery technological instruments and sensors to measure the work put in place accurately. UASs col- lected detailed survey data, which fed into the 3-D model for a project. Therefore, use of a par- ticular technology was complimented by the use of other technologies to gain the full advantage. The DOT staff mentioned using a formal five-step process to investigate and test technologies, as shown in Figure 29. First, during incubation, Wisconsin DOT reviewed external publications and reports to understand the technologyâs benefits. Next, the DOT communicated with other state DOTs to learn how they were using a technology or to see demonstrations of the technology in action. On the basis of the findings during incubation and demonstration, if the benefits seemed to be a good fit and the process to use the technology worked with DOT processes, then the technology moved into a pilot phase. During the pilot phase, Wisconsin DOT collected data and facts about the technologies used on projects. The benefits were recognized, and the actual cost of the technology was considered. Then the benefits and costs were communicated to the project team and upper management. Finally, senior leadership decided whether to implement the technology as part of DOT common practices. One of the issues noted by Wisconsin DOT was the incompatibility of 3-D models that the department created and the use by contractors. Some data provided by the agency in the 3-D model were not compatible with the tasks and technologies that contractors wanted to use on a project. This situation led to contractors having to recreate the model with their internal software to determine the necessary data needed for activities such as AMG and stringless paving; this situation made the use of modeling technologies less efficient. A success factor that helped Wisconsin DOT to understand a technology was to pilot test a technology well before implementing it on a regular basis. Piloting helped to flush out any issues and to troubleshoot the technology; piloting also revealed the level of skill and documentation needed to assist end users. Providing DOT personnel with the chance to use a technology and Incubation Demonstration Pilot test Communication Implemention Figure 29. Five-step process used by Wisconsin DOT to investigate and test technologies. Technology Types Uses Visualization and modeling â¢ Building information modeling LiDAR â¢ Constructability reviews â¢ Fabrication of structural components â¢ Virtual design and construction â¢ QA/QC â¢ Construction inspections â¢ Public communication efforts Interconnected technologies â¢ Earthwork equipment â¢ AMG â¢ Stringless paving Safety technologies â¢ DMSs â¢ Queue detection warning system â¢ Accident avoidance â¢ WZI for motorists Removing workers from harmâs way â¢ Enhanced protection for workers â¢ Incident tracking and analysis â¢ Work zone traffic control Instrumentation and sensors â¢ Remote sensing â¢ Monitoring of progress of work â¢ Locating utilities UASs â¢ Not applicable â¢ Applicable to maintenance and protection of traffic â¢ â¢ Table 23. Technology types and uses for Wisconsin DOT projects.
Case Examples Using Technologies for Construction Delivery 67 become comfortable with it during piloting allowed the technology to move into the implemen- tation phase with fewer issuesâas long as the piloting phase showed the business case for using the technology. If during the pilot test a technology were perceived as too complicated or not cost-effective, then Wisconsin DOT might decide not to use the technology. Visualization and Modeling Staff reported two approaches to using visualization and modeling technologies. The first was the use of 3-D models and visualization by the Southeast Region Freeways team. The Southeast Region Freeways team, created by the DOT to handle major Interstate projects in urban areas in the southeast region of Wisconsin, was using 3-D modeling to construct the $1.7 billion Zoo Interchange project on the west side of Milwaukee, where several Interstate highways intersect (see Figure 30). By using 3-D design modeling along with clash detection for subsurface utilities, Wisconsin DOT was able to find issues with utilities before constructing the work; this process led to a decrease in the number of change orders associated with the utility infrastructure. The second approach to modeling and visualization at Wisconsin DOT was for statewide use, which as staff described, was a less sophisticated approach than the use by the Southeast Region Freeways team. For example, simulation of utility clash detection was an integral tool used for the Zoo Interchange project, but clash detection for utilities became less of an issue outside urban areas of the state. However, Wisconsin DOT planned to use visualization and modeling technologies across the state to recreate most projects as a model and to provide simulations during public meetings. Bringing a set of 2-D plans to a meeting did not translate to the public as well as a 3-D model. By using visualization software and overlaying the model with photogram- metry such as Google Earth, Wisconsin DOT could infuse realism to a project with simulated drive-throughs and flyovers of a project that showed meaningful landmarks within a commu- nity, such as a corner gas station or community church. This augmented reality tool for public meetings was in the pilot phase, with a few projects using this process. The next step was to roll out the AR models and simulations to public meetings in all DOT regions within the state and to train several DOT employees as experts in the use of visualization and modeling tools. Wisconsin DOT used traditional 2-D plans as part of the contract documents, but inevitably saw quickly moving from 2-D plans to 3-D models. All earthwork projects used a 3-D model, although the 3-D models were not contractual documents at the time. Many factors came into play with making 3-D models contractual, such as the legality of the 3-D model and the accuracy Figure 30. 3-D model of the Zoo Interchange project (FHWA 2013a).
68 Emerging Technologies for Construction Delivery of the model versus traditional 2-D plans. As noted by DOT staff, with 3-D models the survey data used and the alignment of the project with existing conditions could dictate the accuracy of the model. As site survey and mapping data collection improved, so did the models. Wisconsin DOT did not have a timeline as to when 3-D models might replace 2-D plans as part of the contractual documents, but continued to learn from practice, working with contractors, and learning from other state DOTs. Interconnected Technologies Wisconsin DOT provided 3-D surface models to show contractors the design intent of a project, and the contractors could use the model at their discretion. The DOT indicated that contractors took a model and rebuilt it according to the project specifications for earthwork and paving operations to develop the AMG needed for interconnected earthwork and paving equipment. Outputs from 3-D design models developed by Wisconsin DOT were not necessarily what a bulldozer or paving machine needed to guide it. The DOT had an ongoing dialogue with the contracting community to discover the compatibility issues, the software and hardware that contractors were using, and the needed construction-related capabilities. Wisconsin DOT saw this as an ongoing process that would improve over time so that contractors did not have to recreate a model to obtain the construction data that they needed to perform earthwork and paving activities accurately. Another area of interconnected technologies in use by the DOT was a pilot program started in 2017 for the use of stringless paving. Before 2017, contractors requested the use of stringless paving, but Wisconsin DOT formalized stringless paving as part of its specifications to test it out on pilot projects. With stringless paving, the DOT found it vital to provide the correct tech- nologies to inspectors to validate the work put in place. The DOT provided RTK rover devices with GPS to inspectors to check slope, elevation, and grade for errors. The success of a hand- ful of projects that used stringless paving in 2017 was enough so that Wisconsin DOT had six stringless paving projects scheduled for 2018. Safety Technologies Wisconsin DOT obtained an FHWA aid grant for construction work zone safety to test and evaluate queue warning system technologies. Using the grant, the DOT piloted the queue detec- tion system on two projects in two regions along an Interstate highway. The layout of the proj- ects with curves and hills provided an ideal situation for testing the system, which helped to communicate to motorists about slowing or stopping traffic ahead to avoid collisions. The queue detection system also provided benefits for bridge rehabilitation projects, which Wisconsin DOT indicated tended to catch the traveling public off guard and leads to an increase in collisions. By piloting the queue detection safety technology, Wisconsin DOT validated the value of the system and defined a program level where it fit in the context of construction safety in work zones. Instrumentation and Sensors Instrumentation assisted the construction inspection process at Wisconsin DOT. Inspectors used handheld RTK rover devices that could read and record quantities quickly and accurately. The handheld devices used LiDAR and GPS similar to light-grade surveying equipment. With inspectors provided with handheld technology devices that measured the placement of work, projects used fewer inspectors, and inspectors no longer needed to carry tape measures and other tools to do the same inspections. Additionally, tablet devices issued by Wiscnsin DOT included an application called OnStation, which inspectors used for Interstate highway projects.
Case Examples Using Technologies for Construction Delivery 69 Typically, inspectors needed to track the station offset from a particular element of a project and related this offset position back to the plan set; the process could be time-consuming and challenging for Interstate projects that extended over several miles. With OnStation, the GPS included in the tablet recorded the inspectorâs actual position, and the plan set could be pinned in the OnStation app that then listed the station offset. Wisconsin DOT staff reported that fig- uring out the station offsets and orientation of an inspectorâs location previously took several minutes, but with the OnStation app, the station offset and location could be determined in a matter of seconds and with a high degree of accuracy. Unmanned Aircraft Systems Wisconsin DOT was not directly involved with the use of UASs for construction delivery. The DOT reported that it struggled with some of the strict FAA regulations, such as no flying over people and keeping a line of sight with the UAV at all times. Without the ability to fly over an active site during normal working hours, Wisconsin DOT did not see the effectiveness of quarantining a project site to fly over it to collect data. The department investigated the use of UAVs for weekend flights over project sites, but that was not a common practice. Wisconsin DOT focused its UAS use on bridge inspections, in which consultants with FAA clearance per- formed the flights. The data collected from flights performed by consultants were passed along to Wisconsin DOT for review and investigation. However, during construction, UAS use was limited, but might increase once the technology increased in use and regulations were relaxed. Lessons Learned In discussions with Wisconsin DOT staff, the following lessons were learned in regard to implementing and using technologies for highway construction: â¢ Have the right people use the technology. Wisconsin DOT noticed that having people with the proper skills, experience, and expertise was a critical component to the successful use of technologies. The DOT reported that expertise was necessary to support the use of technologies, especially when dealing with contractors that were not that familiar with them or used different software or hardware products. â¢ The practicality of a technology. As an overall business strategy, Wisconsin DOT imple- mented technologies that did not require extensive amounts of training or new skills. Further, the department noted that a clear and decisive business reason was necessary to consider an emerging technology for construction delivery. â¢ Use of a formal implementation plan for moving technologies into practice. Wisconsin DOT reported the use of a five-step process to consider, test, and implement technologies: â Learn about the technology from reports and discussions (incubation); â Review demonstrations from other DOTs; â Pilot test the technology on specific projects or tasks; â Communicate within the organization on benefits and drawbacks; and â Implement and evaluate the technology.