Ada County Highway District

ACHD News Thursday, July 29, 2021

The Chip Seal Jive

When you think of dancing, does chip sealing ever cross your mind too? While the chip seal dance may be louder and more clunky than any other dance you've seen on stage, it is no less a work of art. It takes grace, agility, and lots of coordination to make this process a smooth one.

As a resident, you may be thinking about the time you are spending waiting to continue on your journey. But once you see the chip sealing process from start to finish you realize just how quickly the team performs, especially with so many tasks to complete. Commissioner Pickering, who spent her Monday morning with the chip seal crew, said, "I had no idea of all the different elements that created that chip seal. I have a tremendous respect for this team." While there are many moving parts, the ACHD crew makes the process look seamless in their choreographed routine.Photograph of Commissioner Pickering and Chip Seal crew member in jpg

Just like the professionals at the ballet, each member of the chip seal team has an important role. The routine requires great focus, patience, and precision to ensure the safety of the crew and quality of the finished product. A lot of this stems from training, as the ACHD crews also practice their craft before the chip seal season begins, ensuring they're always on pointe.

To get a better understanding of the entire performance, let's start at the very beginning. What does chip sealing entail?

Photograph rollers on newly chip sealed road in jpgFirst, a sealant is applied to cracks to prevent water from seeping to the base. The road is then swept to remove all debris and prepare the surface for the oil before the chip seal crew then begins operations. A distributor truck begins by laying down oil followed by a spreader box to drop down chips. The size of the chips for residential streets is 1/4" and arterials and collectors are 3/8". Commissioner Pickering said she was interested to learn that "the lighter chip means a smoother ride for residential and bike traffic! The heavier chip gives better traction for the bigger trucks on the arterials and collector roads." Rollers will then roll over the chips" we want them pushed into the oil as densely as possible.

The next portion is similar to a conga line, where everybody joins in. Commuters join the chip seal troupe by rolling over the chips, pushing them even further down as the oil hardens over the following days. Once hard, sweepers will then sweep the streets to collect any loose chips before applying a fog seal. This seal is the final stage of setting and protecting the chips. At this stage, you will notice the road take on that smooth and dark appearance we have come to expect.

For the finale', our paint crews take center stage and restripe the arterials and collectors, putting the finishing touches on this annual process.

Photograph of rock chips for chip seal in jpgChip sealing is responsible spending in action. If we were to reconstruct the road, it would cost about $80 per square yard. Chip sealing costs only a small fraction, at about $1.98 per square yard. Not only does chip sealing cost less, it is less impactful to our residents. Commissioner Pickering added, "Chip sealing gives us the opportunity for investment and allows us to put money elsewhere, like community programs. It allows us to spread that dollar further."

Commissioner Pickering was able to meet several members of the chip seal convoy and said she was touched by "how much they cared about their job." She was also impressed by the longevity of many of the team members. Over 200 operators contribute to the chip seal operation and the longest serving team member has been there for over 30 years. Actually, approximately one third of the team has been doing this dance for more than a decade.

Photograph of Commissioner Pickering on Chip seal truck in jpgLike all good dancers, out ACHD crew also has an audience and some pretty big fans. You may have seen our most recent story, Safety Vests and Lemon Zest. They join a number of kids across the county awaiting the promenade and the candy our crews keep on hand to throw their way.

So the next time you're waiting at intermission with one of our flaggers at a STOP sign, think about what may be just around the corner - a carefully choreographed crew dedicated to getting you to your destination quickly and as smooth as possible.


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