Roundabouts are gaining popularity and easy to love. On top of having an elegant design and supporting neighborhood aesthetics, they also improve safety and efficiency for pedestrians, motorists, and cyclists.
According to a study published by the Federal Highway Administration and Insurance Institute for Highway Safety, roundabouts also reduce crashes by up to 35% and personal injuries by up to 75%.
Gang 233-St. Martin, of the Louisiana Department of Transportation and Development’s (LADOTD) Lafayette District, is currently overseeing the construction of a new roundabout at the intersection of LA-347 and Doyle Melancon Road. The $2.5M project entails replacing a traditional 4-way stop at this busy intersection with a roundabout. Traffic delays, personal injuries, and property damage caused by the current intersection design were a major source of frustration for travelers and this new roundabout is a welcome addition to the parish.
“The old blinking light intersection is just south of Breaux Bridge High School and the school traffic causes a backlog,” said Christopher Chavez, St. Martin Gang project engineer. “During sugarcane season, large, slow moving vehicles trying to pass safely through the 4-way stop caused further delays and had potential for accidents,” said Chavez, adding, “Getting tractor trailers through that intersection was difficult.” He also cited the often-exceeded 45-mph speed limit on LA-347 as another contributing factor.
Construction of the roundabout has had the expected impacts to the current flow on the roads due to traffic shifts and intermittent lane closures. With that, and it being a publically-funded project, even slight delays could cause an uproar from the taxpayers, driving both public interest and the need for timely project delivery.
Investing in Innovation
In recent years, LADOTD has been looking to strengthen its e-construction program by piloting and adopting new technology innovations in order to increase efficiency and reduce construction project cost overruns. A key investment has been augmenting outdated, paper-based inspection processes with technology that provides photo-based inspection capabilities—a solution called HeadLight.
Unlike the traditional inspection process which entails recording project inspection activities in a notebook, HeadLight enables inspectors to digitally document project inspection data and visual media using a cellular-enabled mobile device. This information, captured organically throughout the work day, syncs to the cloud every 10 minutes, providing a virtual window into the jobsite for stakeholders across the organization.
Design Element Requirements
Although the features of all roundabouts are uniform, many of the design elements, techniques, and construction parameters are anchored on the average roadway speed and the expected traffic volume of the individual site.
The heavy traffic, axle-load tilting, and centrifugal forces at a roundabout exert extreme stresses on the pavement, making them more prone to a wide range of issues including cracking, rut formation, surface aggregate loss, and deformation of the wearing course.
For these reasons, precise joint design, construction, and placement in the central, approach, and transition zone at the LA 347 and Doyle Melancon Road intersection was initiated to reduce maintenance cost, life-cycle cost, and the overall rigidity of the entire structure.
Concrete Damage Necessitates Repairs
During construction, the contractor’s heavy equipment traffic across a recently poured section of the roundabout chipped the concrete which had to be removed and repoured. To repair, the contractor saw cut straight across the full width of the panel, removing the damaged concrete. Engineering Tech-7, Dustin Murphy, visually documented the form placed ahead of repouring the chipped section and a circle panel. He noted the new joint created by the form would create a stress point.
“They would have made a point in the concrete pour which would have ended up cracking,” explained Murphy.
Tech-7 Dustin Murphy’s image observation features a collage pairing a close up of the formed up section and wide shot for perspective. The pictures, along with his notes, allowed the gang to quickly make an informed decision on the correct course of action.
Chavez further explained, “The contractor initiated a fix to repair the damage, but their fix was incorrect. We don’t like to have points in any of our concrete panels because what happens is you develop a crack, staring at the edge and continuing to mitigate, so we try to avoid any small, acute angles in our concrete sections.”
This was a powerful discovery, considering that without being correctly tied to the adjacent slab, over time, the joint wouldn’t have been able to bear the recommended weight, causing major structural integrity issues. “As soon as you put a load on there, it’s gonna be one of your first places to crack,” said Assistant Project Engineer, Zachary Ardoin.
HeadLight’s adeptness in capturing photo-based observations made it easier for the project inspector to document a joint layout issue, communicate it to the project engineer, and advise the contractor on the required corrective action in advance of work progressing.
In addition to the photo, which documents improper forming up of the new joint layout, the inspector, Ty Trahan’s, image observation is rich with granular details including: a searchable title and description, automatic date/time stamp and geolocation capture, station and offset notation. Project-specific labels for categorization facilitate the tool’s robust search capability.
HeadLight’s ability to chronicle critical project data such as inspection activities, material test results, and conformity to plans, specifications and quality standards, provides project engineers and construction section leadership a detailed, real-time view into jobsite activities from wherever they are working that day.
Rapid Time to Value
The inspectors assigned to this project identified an improper joint layout which would result in a concrete stress issue. Their documentation of the issue (which was captured just a few hours into the first day of training with the HeadLight software) facilitated a quick collaboration with the engineers to devise a solution. The next morning, the inspectors advised the contractor on the required corrective action in advance of work progressing, preventing waste of labor or materials, and saving the agency the expense of future repairs.
This informed decision making, based on detailed visual documentation, occurred only one day after the inspectors swapped their status quo inspection process for HeadLight! Despite being a new technology and process they were able to aptly do their job and more effectively communicate with both their team and the contractor. HeadLight provided visual proof of the issues in real-time which eliminated project delays and prevented the need for potential rework that may have followed otherwise.
LADOTD project engineers and inspectors review HeadLight entries and construction plans in the field office and quickly resolve the joint issue without having to drive out to the project site 15 miles away.
L to R: Engineering Technician 5, Donald Stevenson, Engineering Technician 4, Ty Trahan, Engineering Technician 7, Dustin Murphy, Engineer 4, Zachary Ardoin (seated) and Project Engineer, Christopher Chavez.
With innovative partners like LADOTD, HeadLight continues to support successful project delivery throughout the infrastructure construction industry. Thanks to its minimal technical and training barriers, it has been proven as an easily deployed and quickly adopted solution, allowing our clients to hit the ground running from day one.