EXECUTIVE SUMMARY

he movement toward building information modeling (BIM) for transportation projects has propo- nents around the globe, but it has yet to expand into widespread adoption. The reasons include entrenched practices that worked well for a long time, an older

generation hesitant to learn new skills, and engineers’ conservative nature when it comes to technology that hasn’t been tried and tested. However, with a proliferation of visible beneftts, BIM is being extended to much broader applications than just buildings.

Transportation is perhaps the largest beneftciary of this managed modeling approach, given the state and quality of transportation infrastructure. The will to address the increasing need to replace deftcient infrastructure (particu-

larly bridges) also can be fortifted by BIM tools, because they model detailed construction costs and reduce construction errors for better value for each taxpayer dollar.

The BIM approach centers around an intelligent model shared across team members, acting as a collaborative hub throughout the entire lifecycle of an asset. The model can start at asset conception or later via highly detailed and automated data-capture technologies. The model gains intelligence as it gets passed among different practitioners who add their expertise, document conditions, or add opera- tions and maintenance actions. The well-documented work assists and improves operations while reducing costs.

The game-changing processes and workflows start when companies adopt BIM tools to create a business advantage as well as differentiate and market themselves against competitors. BIM adoption culminates when it becomes standard business practice, as it has in many engineering and infrastructure design and construction ftrms. Owners are increasingly mandating a BIM approach, and it’s being adopted by project participants who understand they can deliver a better product at a lower cost and differentiate themselves as industry leaders.

This white paper takes stock of the current adoption and documents some of the advantages of BIM for transportation projects and practice. There are beneftts along the lifecycle of an asset, which translates to growing acceptance of BIM for new projects as well as ongoing operations.

As the evidence for cost savings and improved efftciency accumulate, there’s growing interest to mandate its adoption. In the United Kingdom (UK), the government used BIM in high-proftle projects and advanced its adoption by extensive nationwide training. The government sees the approach as an advantage and an economic driver, where British ftrms will stand above others as well as command a higher wage.

Adopting new ftnancing mechanisms for infrastructure projects, such as “Public-Private Partnerships (P3),” stands to accelerate adoption. This business approach will demand a higher degree of cost accountability due to the Wall Street investment and oversight, and BIM is poised to provide that.

Ultimately, this model-based approach ushers in next-generation transportation options that promise

more-efftcient movement of people and goods with reduced trafftc congestion and emissions, and far greater safety.

Autonomous vehicles are one such advancement, and these computer-driven cars are greatly helped by the detailed road models that BIM can provide to assist their navigation.

WORKFLOW EFFICIENCY GAINS

Every infrastructure project takes a phased approach, involves multiple stakeholders, and requires many coordi- nated teams for design, engineering and construction. The projects’ complex nature generates a lot of information that requires coordinated sharing as well as detailed man- agement of the construction timeline, materials ordering and overall cost.

BIM has advanced primarily because of this informa- tion-sharing requirement, avoiding the bottlenecks that a paper-based or 2-D digital representation entail. The modeling, and more speciftcally the collaborative work around a shared model, provides a leap forward in efftciency. Modeling also eliminates most of the costly misunder- standings when coordinated teams become uncoordinated. The model provides the means to share each phase of work and resolve any conflicts with the individual project components or schedule before they become time- and money-wasting issues on the ground.

Workflow is where model usefulness becomes most apparent, largely due to the complexity of infrastructure projects. Transportation projects bisect the underground infrastructure of water, sanitary and storm sewers, and electrical and gas infrastructure. Details on these existing conditions and the potential for conflicts must be known and recorded. The model becomes the place for that, with the modeling process progressing from planning to pre- liminary design, detailed topographic and asset surveying, detailed design, construction, and then maintenance. BIM is helpful for all such phases of design and engineering as well as along the project construction timeline and assets’ entire lifecycle.

Winning Projects

The civil-engineering business model operates on a traditional sales funnel with the project universe at the  top. Companies must seek out projects and clients, provide concepts to compete, and show why their ftrm should win these projects and represent the client. As the business-de- velopment funnel shrinks, it’s critical to turn those pros- pects/projects into clients and business.

This can be very expensive when bidding and develop- ing concepts on a number of projects. With the ability to rapidly generate “in-context” models, with multiple alter- natives and approaches to prospective clients, companies can generate ideas, validate preliminary constructability and demonstrate that they’re innovative from a bid-propos- al standpoint as well as more apt to successfully execute the project through better public stakeholder understand- ing with rich and intelligent 3-D modeling.

Planning

In a project’s planning phase, managers work to priori- tize the dollars they have to invest, singling out the most critical maintenance tasks, and prioritizing new projects based on impacts and objectives. A city, county or state transportation department will have a detailed representa- tion of their roadways as well as a backlog of projects that have received some form of vetting and approval.

Often this information is map-based, but BIM is in- creasingly the decision-making tool that combines existing knowledge with plans. This phase involves comparing costs and effects as well as some modeling of different scenarios before any dollars are spent in the fteld. After projects are vetted and approved, they’re sent to a designer for ftnal design and plan documentation, and then let out for bid by contractors.

Data Capture

Before the design phase begins, a topographic survey is needed with an accurate 3-D representation of the project area. Traditional data collection involves professional surveyors capturing measurements and providing a 2-D map view with contour lines for elevation changes. New tools have advanced that deliverable to return a highly accurate

3-D representation that forms the basis for design and simpliftes communication.

“Reality Computing” is a new term that encompasses the many ways data are captured from the physical world, put to use with digital tools to create designs, realized with land change and visualized for communication. For anyone engaged in the design, delivery or management of physical projects such as transportation, Reality Computing breaks down the bar- riers between physical and digital worlds.

New technologies enable the direct capture of spatial information about the physical world for integration into design processes. Design context is moving from geometry (modeled representations of

the physical world) to captured reality data. Reality Computing helps design teams improve accuracy and accommo- date physical-world conditions through customized fabrication of a design shaped to ftt precisely with real-world conditions and environments. Furthermore, a tech- nology explosion is affecting how digital projects or products can be realized in the

physical world, from 3-D printing and machine-controlled grading to augmented-reality devices that allow users to see above and below ground.

Light detection and ranging (LiDAR) uses infrared laser light, instead of radar, to bounce off objects and

return details about surroundings in what’s called a “point cloud,” with each point representing a surface that the light bounced back from. The point cloud provides detailed ground-surface measurements as well as accurate represen- tations of roadside assets such as lamp posts, curbs, storm drains, guardrails, signs, overpass and underpass clearance and complexity, and surrounding vegetation.

Mobile LiDAR flown on helicopters, airplanes and UAVs, or mounted to vehicles that drive roadways, provides detailed capture of an entire project site more quickly and cost effectively than traditional survey methods. Such de- tailed 3-D capture is tailor made for the BIM starting point, as it provides the measurements and visualizations that can easily be turned into a model. More automated processes are coming to market to extract features from point clouds for faster movement from point-cloud capture to the realization of models that represent true project conditions.

Detailed Design

True modeling begins at the detailed design phase.

Existing conditions are brought into the modeling environ- ment, where designers build detailed 3-D models for cre- ating construction plans and drawings as well as measure- ments and details of the required materials and quantities to begin procurement.

Designers also are increasingly turning to BIM to un- derstand performance. They can model different types of intersections and roadway conftgurations and use simula- tions to show the actual trafftc volumes at different times of day to see how different options perform. Such testing with simulated trafftc volumes becomes a critical input  to the decision-making process to ftnd design alternatives that perform best.

With each added degree of project complexity, BIM proves its worth that much more. Such complexities may include a need to widen roadways while increasing bridge clearances, providing for better stormwater management, buffering around a landftll site, accommodating new devel- opment, and incorporating light-rail corridors and connec- tions. Although this may be an extreme example, compet- ing design parameters often need to be carefully weighed and tracked, and detailed models provide the means to achieve greater awareness.

“I don’t want to say the ‘old days,’ because it wasn’t that long ago, but we would march further ahead in the design process before coming to the presentation stage. If there needed to be a significant amount of change, then there was a considerable amount of redesign before you got back to presentation stage. Now that whole process is to design a little, present a little, and it’s much more efficient.”

- Scott Reed, PE, Huitt-Zollars