When the Colorado Department of Transportation (DOT) realized it needed more cameras over Denver area freeways, the department didn’t just put up another camera – it got a big balloon. The agency completed a two-day pilot on June 11 to test the effectiveness of a camera-equipped blimp, or aerostat, for the detection of and response to incidents on the state’s roadways. A job usually reserved for stationary cameras, department officials said they wanted to try something different. The first state DOT to use an aerostat for traffic monitoring, the project could pay off in performance and cost savings for the state.
Through a partnership with Colorado Springs-based Sky Sentry, the state borrowed a 1,600-cubic-foot aerostat and equipped it with two high-definition cameras. The tethered balloon allowed officials to attain a view from 400 feet up, allowing a view of up to more than 10 miles. The balloon, which was located near one of the department’s node buildings, allowed anyone with access to the camera control system to view a live stream of the video and then zoom, tilt or pan the camera to get a better shot of the action.
The balloon used for testing, which the state has not yet purchased, costs about $50,000 according to officials, and a full implementation of such a project would cost about $200,000 to $300,000, considering the purchase of cameras, a trailer for the balloon, and technical considerations. A static camera implementation like what’s used elsewhere throughout the state would likely cost about $500,000 for the same performance. The potential cost savings associated with the project are substantial, but the bottom line for the state is performance, said Amy Ford, CDOT director of communications.
“We are trying to be on the cutting edge of what is out there to best facilitate the information-gathering and incident management and detection and how do we manage our roads,” Ford said. “And so we are open to all ideas – from a technology perspective, from a use perspective, from a cost-effectiveness perspective, we have one goal and one goal only and that is to use that data and that information to make our roads as reliable as we can and as safe as we can.”
Making the roadways efficient is ultimately a bigger cost savings anyway, said Ryan Rice, director of CDOT Transportation Systems Management and Operations.
“We have literally hundreds of incidents, ranging from a flat tire to a semi rollover every single day in the Denver area,” Rice said. “In trying to detect those and know about them in a timely manner, the much bigger cost is in being able to detect an incident faster and know what type of response and resources are needed to clear it.”
Rice recalled a recent incident in which a hydraulic lift being towed had been turned over on the freeway, blocking a lane of traffic, and when they tried to move it out of the way, it began blocking another traffic lane. The whole thing was a mess, he said, and knowing from the outset what they’re up against is the kind of value that a high-flying balloon might bring.
“That’s an example where if you know exactly what the situation is at the earliest moment, you can coordinate and get the appropriate resources there faster to get it removed, because certain incidents may just require a tow truck, but others may require something more,” Rice said. “It may be a truck that requires a heavy tow, so the overall cost savings in reducing congestion is the bigger driver that we’re looking at.”
Rice characterized the pilot as having gone “really well” overall, but said the state has more analysis to do in comparing the price against traditional cameras. There are a lot of considerations when it comes to blimp cameras, such as image stability, a problem the state encountered early. The blimp was originally equipped with an additional 360-degree view camera, but it had to be removed to make the balloon more stable, since the other camera was purchased without gyroscopes in an effort to keep pilot costs down. Removing the second camera helped considerably, Rice said, but image stabilization remains a challenge.
The state also had other considerations. Officials weren’t sure how well the images would appear at night, or how the balloon would perform in a storm. Unlike stationary cameras, a tethered blimp requires a babysitter. That’s an expense, Rice said, but on the other hand, the department’s nine maintenance workers already spend about a quarter of their time cleaning snow and chemicals off the state’s stationary cameras.
Citizens occasionally steal, shoot and vandalize stationary cameras, but one thing they don’t do is float away or deflate, something Colorado learned about early. On the day before the pilot, June 9, the aerostat deflated as part of an accidental self-destruct sequence. The balloon’s GPS tracker had become dislodged, leading the aerostat to think that it was floating away, and as a safety precaution, the balloon deflated. The incident was ultimately little more than a learning experience, but demonstrated, nonetheless, that with every new endeavor comes new challenges to consider.
The state reported that it plans to evaluate the idea in the coming weeks and then release a report to share what it has learned.