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Alabama DOT Reconstructs State’s Busiest Roadway with BIM Processes

Alabama DOT Reconstructs State’s Busiest Roadway with BIM Processes

Bentley’s Integrated Applications Optimized Design Verification to Save $10 Million

By Amy Heffner

A Massive Reconstruction Initiative

The only east-west interstate through Birmingham central business district, the I-59/I-20 interchange is Alabama’s heaviest traveled corridor, accommodating more than 160,000 vehicles per day. Built in the 1960s, the six-lane divided highway has minimal shoulder width and has more than tripled its original traffic capacity. As a result, more than 600 accidents have occurred within the past four years. The infrastructure has become functionally obsolete, with structurally deficient bridges and inefficient roadway alignment. To improve functionality, safety, and overall capacity of the 3.5-mile city interchange, the Alabama Department of Transportation (ALDOT) initiated a USD 750 million reconstruction project.

“This is the largest amount of money and largest amount of traffic ALDOT has ever dealt with in one place,” said John Cooper, director at ALDOT.

The massive renovation included construction work for 36 bridges, roadway widening, and utility work. Subject to a fast-paced schedule, the project presented numerous coordination challenges and changes in the overall design scheme. ALDOT Visualization Group was tasked with coordinating data access and information exchange among multiple offices and utilities, as well as communicating with the public and stakeholders, to quickly deliver an accurate 3D model that could be provided to contractors for precise cost estimates. These models were then referenced to complete phased construction within 14 months.

Collaborative Digital Engineering

To optimize information exchange and meet the fast-paced schedule, ALDOT implemented a collaborative 3D BIM process. With no precedent for developing the digital engineering model, the team relied on Bentley’s integrated 3D design, collaboration, and visualization applications to facilitate the BIM strategy. ALDOT first modeled the existing site and infrastructure from more than 2.3 million data survey points using Descartes and MicroStation®. Then, they established an open, connected data environment using ProjectWise as the collaborative platform to seamlessly share and exchange models and information. The team used OpenRoads™ to create the digital terrain models and StormCAD, CulvertMaster, and FlowMaster to address drainage and utilities design. All 3D models were imported into MicroStation for design verification and clash detection to generate a comprehensive 3D model.

To support precise cost estimation and lower bids for the project, it was critical that the 3D digital engineering model include accurate and timely data to support multiple uses. ProjectWise allowed designers, department heads, drafters, reviewers, and consulting teams to have real-time, electronic access to all project files, and ensured that everyone was working on the right data. The software provided an open, connected data environment to streamline information exchange throughout the project lifecycle, accelerating accurate, integrated 3D modeling.

“This was the biggest game changer. Using ProjectWise for data and information exchange worked fantastic,” said Matt Taylor, P.E., state engineer at ALDOT.

Model accuracy also played a critical role in avoiding construction delays. Using Bentley’s 3D engineering design and construction analysis applications enabled ALDOT to identify potential issues and potential construction delays before the project broke ground, eliminating costly on-site errors and keeping the project on schedule. Integrating LumenRT to produce and present animated renderings of the 3D model through Live Cubes to city officials, stakeholders, and the public brought visualization and understanding of project impact, alleviating concerns and accelerating project approval.

Maximizing Model Potential

ALDOT sought to maximize the potential of the digital engineering model for multiple uses, including visualization, design checks, construction analysis, clash detection, right-of-way (ROW) negotiation, lawsuits, and aesthetics. Using the 3D model facilitated design verification, which allowed the team to check horizontal and vertical clearances and bridge elevations and identify exposed footings and elevation issues prior to construction. Utility companies examined the model to ensure there were no clashes. Utilities are a critical element in any construction project and ALDOT invested millions into locating and relocating them. Having a visual 3D representation of the utility infrastructure enabled ALDOT to perform clash detection. For instance, the model showed one of the utility companies that the new roadway would not adversely impact their equipment, preventing expensive utility relocation. Overall, the ability to perform clash analysis on the 3D model using MicroStation resulted in ALDOT identifying more than 1,100 design and construction clashes.

“One great thing is that we were able to provide everything to the contractors to pre-bid. Every contractor that bid got a full 3D model,” Taylor explained. As ALDOT’s first project submitting 3D models for bidding, model accuracy was significant to support precise cost estimation and meet the organization’s goal of lowering construction bids. Using Bentley’s integrated modeling technology accelerated design and improved quality to deliver accurate models to construction bidders for more informed cost and time estimates. The contractors maximized usability of the BIM model by clicking on specific items within the model to determine precise quantities for creating cost estimates.

Lastly, the 3D BIM model along with Bentley’s reality modeling technology maximized visualization potential necessary to demonstrate project impact to all stakeholders and the public. With Live Cubes in LumenRT, ALDOT generated animated renderings that facilitated visual understanding of the design and its effect on the surrounding environment and community to optimize ROW negotiations and enable more informed decision making.

Integrated Applications Deliver Savings

This highly sensitive project had to be designed quickly, efficiently, and accurately. Using Bentley’s design and collaboration applications allowed all parties to achieve this goal and save millions. ProjectWise established an open, connected data environment that helped consulting firms save tens of thousands of hours creating the 3D models to meet the rigorous scheduling demands of the project. The collaborative software provided inspectors and contractors real-time access to design files on tablets, eliminating lengthy meetings and manual review and workflows, saving hundreds of hours. Coordinating information sharing through ProjectWise saved ALDOT an estimated USD 50,000 and 40,000 resource hours.

“MicroStation clash detection was hands down the most effective technology utilized in the project,” commented Taylor. ALDOT saved over USD 10 million by implementing this software feature. The reports generated from this BIM review methodology allowed designers to fix costly design and construction errors prior to project bidding, ensuring utilities were properly located and eliminating construction change orders. Having an automated and optimal design review process avoided construction delays and reduced construction time by 65 days.

Integrating LumenRT with MicroStation visualization capabilities allowed ALDOT to provide dynamic visual representation of the project rather than traditional 2D drawings to optimize project understanding. This facilitated public and stakeholder communication as well as saved ALDOT USD 2 million in lawsuits filed based on misinterpretation of ROW lines. The animated renderings demonstrated how ROW lines were not only legitimate but also improved surrounding properties.

Rejuvenating Downtown Birmingham

Currently under construction, the project continues to use ProjectWise as the method for sharing and exchanging information in real time with on-site teams through mobile devices. The 3D BIM model produced with Bentley’s digital design applications enabled ALDOT to effectively convey the design to the people of Birmingham, meeting its responsibility to the public to not only build safe infrastructure but also save the public money. Bentley provided ALDOT an integrated technology solution to meet developmental needs of the city of Birmingham while reducing environmental impact by minimizing noise levels in the developed urban area. The new, structurally safe and functional roadway infrastructure provides better interstate access by consolidating ramp locations, creating an area for improved park space beneath the bridges.

This mega-reconstruction project is reuniting the north and south sides of central Birmingham where they once were divided by the urban I-59/I-20 interstate. It has provided the catalyst for rejuvenating Birmingham with the new City Walk initiative, which will add parks, walking paths, cafes, and music venues, increasing commerce and economic growth within the community.

Project Summary

Organization:  Alabama Department of Transportation

Solution: Roads and Highways

Location: Birmingham, Alabama, United States

Project Objectives:

  • To implement digital workflows to coordinate information exchange and meet the 14-month construction schedule for the reconstruction of Alabama’s I-59/I-20 corridor.
  • To develop an accurate 3D BIM model to optimize design and cost estimates.
  • To effectively convey design and project impact to stakeholders and the public.

Products Used:

CulvertMaster, Descartes, FlowMaster, LumenRT, MicroStation, OpenRoads, ProjectWise, StormCAD


  • ALDOT initiated a USD 750 million reconstruction project to improve safety and functionality of the I-59/I-20 interchange in central Birmingham.
  • The visualization group delivered a 3D digital engineering model for multiple uses to meet the 14-month construction schedule.


  • Using ProjectWise to coordinate information exchange streamlined workflows among the numerous consultants to save 36 days in delivery time.
  • Performing clash detection in MicroStation identified 1,100 errors, saving USD 10 million and 65 days in construction time.
  • Bentley’s integrated applications enabled ALDOT to produce an interactive 3D model for contractors to optimize cost estimates.

    Amy Heffner is a manager of civil product marketing at Bentley Systems, focused on the promotion of Bentley’s civil design applications, including OpenBridge, OpenRail, OpenRoads, and OpenSite.