Developing a detailed model is an important early step in any construction project. Creating that realistic, and meticulously accurate model of a project not only uncovers potential project issues that might have been missed in earlier, rougher sketches, but also creates a realistic expectation of what constructing a project will cost. And perhaps even more importantly for any government entity, realistic and accurate depictions of what a project will look like when it’s done can be a great tool for educating the public on what you’re doing with their taxpayer dollars.
Unfortunately, doing the surveying necessary for this kind of modeling takes time. Take the Mill Creek Trail in the northern part of Cincinnati. To build a new 4,500 linear foot segment, it would take a week of surveying to get the kind of detail necessary using traditional survey methods. That’s a week added into the project timeline and a week of paying surveyors to be on site.
But is that the only way?
We recently sat down with Kevin Foster, Business Development Manager at TrueScan3D, who spoke at Autodesk University about their innovative, high tech alternative to traditional surveying, which they utilized for the aforementioned Mill Creek Trail segment. Using a combination of emerging technologies such as laser scanning, drones, and the adaptability of the Infraworks program, they managed to get extremely close – just within two to three inches – of the accuracy of a traditional survey team in just one day. That’s a time savings of 86 percent.
We wanted to find out what Kevin and TrueScan3D learned during this process and what wisdom he could pass on to anyone who is looking for a faster approach to design modeling. Here’s what he had to say:
GovDesignHub (GDH):Can you tell our readers a little bit about the project you discussed at Autodesk University? What were the residents of Cincinnati looking to build? What roadblocks were standing in the way?
Kevin Foster: When Truescan3D spoke at Autodesk University last fall, we discussed the Mill Creek Trail project. The project focused on extending a segment of an existing trail network to the Sharon Woods Nature Park in the northern part of Cincinnati. The new trail segment was approximately 3 miles in length, but the focus area of our project was about 4,500 linear feet.
The local municipalities were seeking to apply for funding for the trail and needed to provide a set of design development level drawings and a cost estimate as part of the funding application. The biggest roadblock was that the trail corridor was very tight, with many potential issues in our area of primary focus. These multiple concerns and unknowns could significantly impact the project budget or even change the proposed route of the trail.
To understand the costs and design implications, this area needed a much higher level of documentation than what currently existed. Typically this substantiation would be done by performing a traditional survey of the completed area. However, the local municipality did not have the additional funds to survey approximately one mile of trail in a complex area while not knowing they would be awarded funding.
GDH:How did the model that you employed for Cincinnati – utilizing laser scanning, drone imagery and Infraworks – help to overcome those challenges?
Kevin Foster: There were several areas where this approach helped us in addressing the challenges. First, Truescan3D understood our team had to develop a way to document the site at a much lower cost than a traditional field survey. This was the only option to ensure the project was feasible for the community. Laser scanning and drone imagery allowed us to generate detailed documentation to produce design development level drawings and an accurate cost estimate.
We were able to collect the field data in a just under one day. Traditional survey methods would have taken more than a week. We set ground survey controls, performed our drone flights and supplemented our data with laser scanning. The laser scanning was done in limited areas we could not pick up clearly with the drone. These included bridge underpasses, and land hidden by vegetation, for example. The drone data and laser scanning successfully produced a level of detail that allowed us to produce DD level drawings and a cost estimate.
Once we collected the field data, we used Autodesk Infraworks to create a model of the proposed site in a short amount of time. Infraworks was the ideal tool for this work, because it allowed our Truescan3D team to create a model of the proposed site in a short amount of time. Infraworks allowed us to not only incorporate existing GIS data into the model, but also import our scanning and drone information we collected and then overlay the proposed design on top of all that information.
GDH:Before you started using this drone, radar and InfraWorks approach, how would you have had to do such detailed modeling?
Kevin Foster: To document the site, we would have typically started by pulling existing county GIS maps and aerial photography. This information is generally good enough for planning or schematic design purposes. However, these maps and aerial photos may be old and would not depict any changes that may have occurred over time. This level of information is not detailed enough to do construction drawings or cost estimates from, so we would have had to perform a survey on the site. A traditional survey would have been much more expensive.
Before Infraworks there was not a robust tool with which we could model quickly. Once we had the design, Infraworks directly imported all of the site information we collected. While there are other 3D modeling programs that allow you to produce similar results, they do not offer the ability to easily import existing conditions and reality capture data. This has proven to be a big time saver and made Infraworks the best choice for the project.
GDH:What benefits does the drone and laser scanning approach deliver, both during the model creation phase and once you have that model as a finished product?
Kevin Foster: The real value of the drone and laser scanning approach is that, for a very reasonable cost, it delivers precise documentation of the existing site the day you begin your project. Because the data we’re using to build our Infraworks model is accurate, the client understands two important factors: current project issues and how much it will cost to address them in the engineering design.
The visuals in the model are realistic, so what the public sees is not going to change drastically due to unforeseen issues. The scanning and modeling is a tool that educates us about the site or project we’re working on and reduces the risk of discovering issues as design or construction moves forward.
GDH:What advice would you share with municipalities that are thinking about including this kind of scanning in their construction process? What best practices or lessons learned can you share?
Kevin Foster: My biggest piece of advice is to remember there is not one solution that fits all projects and potential issues. Each one is a little different. Invest time upfront with an experienced service provider who can help you assess and evaluate the right solution for your specific project. Because there are many tools for reality capture and modeling, you have many options from which to choose before you begin. Truescan3D’s goal on all projects is to develop a detailed understanding of the client’s pain points and determine their needs. We take that information and design a solution to achieve their project goals.
Regarding best practices, I would stress that using laser scanning and drones to collect information be considered for more than just during the design process. It would be to the municipalities’ and owners’ advantage to think of reality capture as a tool that can be applied during all phases of design and construction, not just the early phases of a project.