Transportation

Providing DOTs with 3D Modeling Technology Guidance

When state department of transportation officials need technical guidance for the deployment of three-dimensional (3D) and four-dimensional (4D) engineered models for construction, they consult guidelines provided by the Federal Highway Administration (FHWA).

When the FHWA needed a firm with expertise in this modeling technology to create those guidelines, it looked to WSP | Parsons Brinckerhoff.

Cover Efficient Geospatial Data Geospatial 3D techniques

WSP | Parsons Brinckerhoff, as a consultant to Applied Research Associates, has been advising the Federal Highway Administration on the development of documents that support the deployment of 3D engineered models for construction.

Over the past year, a development team from WSP | Parsons Brinckerhoff, as a consultant to Applied Research Associates, has been advising FHWA on the development of documents that support technology deployment of 3D engineered models for construction. The project is part of the FHWA’s Every Day Counts (EDC) program, an initiative to speed up the delivery of highway projects and address the challenges of limited budgets.

To develop these “how to” guidance documents, real-world projects were identified as part of FHWA’s engagement with state DOTs at the EDC regional summits, where this innovation was rolled out.

“Since then, WSP | Parsons Brinckerhoff has worked to plug critical gaps in the current understanding with regard how 3D-engineered models can be used during and post-construction,” said project manager Jagannath Mallela, director of research and innovation solutions at WSP | Parsons Brinckerhoff. “Our goal was to develop case studies that don’t merely document successful practice, but provide context and lessons that others can use in their decision-making,” he said.

“Our objective is to provide guidance to DOTs that have not engaged in this technology yet,” said Alexa Mitchell, a civil integrated management consultant for WSP | Parsons Brinckerhoff. Mitchell and Mallela are two of the main authors of the documents.

Three-dimensional modeling has been used for quite some time in building construction. “But for transportation, it’s still a relatively new thing, and it can take a lot of work to apply this resource effectively,” Mitchell said.

The Fourth Dimension

The scope of work for FHWA over a two-year period includes the delivery of six case studies, which highlight the successful use of 3D and 4D engineered models, and nine technical “how-to guides” to help transportation agencies with their implementation efforts. Thus far, five of the six case studies and three of the guidance documents have been completed and are now available on the FHWA website.

Jagannath Mallela, Geospatial 3D Techniques

Jagannath Mallela

Alexa Mitchell Geospatial Data Geospatial 3D Techniques

Alexa Mitchell

While a 3D model measures a project’s length, width and depth, a 4D model adds a project schedule to create a simulation of construction activities from start to finish, or for a specific task and timeline. It is a visual tool that pulls together project information from many sources that fosters collaboration between stakeholders and engineers. It is typically used for large, complex, multi-year, multi-contract projects that benefit from a coordination of multiple schedules.

“Case studies provide excellent opportunities to learn about the successes, the challenges, and how DOTs are using the technology to reach their goals more quickly, safely and cost effectively,” Mitchell said.

For example, it can improve collaboration on projects with numerous contractors and reduce the risk that one element of a project will conflict with another.

“This technology has allowed designers and owners to collaborate with construction staff in a way that was not possible before,” Mitchell said. “This type of collaboration can be optimized to provide alternate solutions to complex problems and mitigate risks early in the process.”

Filling the Gap

The new documents cover a variety of relevant modeling topics. For example:

  • The Guide for Efficient Geospatial Data Acquisition using LiDAR Surveying highlights the benefits of using laser technology as a surveying tool to support current transportation agency business applications.
  • Geomatics Workflows: California and North Carolina Integrating Light Detection and Ranging (LiDAR) into Existing Practices uses case studies in California and North Carolina to illustrate how state transportation agencies can expand the use of LiDAR sensors in 3D engineered models.
LiDAR, benefits of laser technology, Geospatial 3D Techniques

©WSP | PARSONS BRINCKERHOFF

The guides also highlight the benefits of using laser technology – or LiDAR, which was used to create this tunnel scan – as a surveying tool.

Mitchell, who previously worked for the Missouri Department of Transportation, said that as a former DOT manager, “I know how hard it is for agencies to dedicate the resources as technology evolves. So having subject matter experts helping set best practices at the national level is of great importance to me.”

Because the technology is evolving at such a rapid rate, it is often difficult for DOTs to adopt it into their processes. “Many times, DOTs simply do not have the expertise in house to develop their own guidance, and these types of documents fill that gap,” Mitchell said.

While 3D and 4D technology is constantly changing, it has proven to be effective for transportation projects. “That’s why FHWA is promoting these technologies,” Mitchell said. “These documents provide a starting point to initiate an agency’s implementation plan to adopt this technology.”

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