Keeping city streets smooth and safe is a task we tackle every day. When a roadway begins to rut, crack, or lose its profile, our crews don’t always need to tear everything out and start from scratch. Instead, we often choose asphalt milling-also called cold planing-to remove only what’s worn while preserving what still works.
Follow this link https://www.arra.org/page/coldplaning to know more about cold planing.
By blending technical precision with practical field knowledge, we can extend pavement life, cut costs, and lessen the environmental footprint of roadwork. It’s a core strategy in any modern pavement resurfacing program, especially for agencies striving to stretch limited budgets without compromising quality or safety.
What is Pavement Milling?
Pavement milling is the controlled removal of a set depth of asphalt using a rotating drum fitted with hardened carbide cutters. As the machine advances, it grinds the surface into chips that are swept onto a conveyor and sent to waiting trucks. By trimming just ¼ inch-or as much as several inches-we create a fresh, level platform ready for an overlay, a rejuvenating sealcoat, or a quick line-striping refresh.
On municipal arterials, we frequently mill one lane at a time so traffic can flow in an adjacent lane, minimizing disruption. The resulting texture delivers superior bond strength once tack coat is applied, which translates to a longer-lasting wear course and fewer premature failures. We also rely on milling to eliminate drainage dips, remove polished aggregate that causes skidding, and tie new asphalt neatly into curbs and driveway aprons. These refinements help our roadway rehabilitation projects stand up to heavy truck traffic and reduce future maintenance demands.
Recycling Removed Asphalt
Those steady streams of millings are not waste; they are recycled asphalt pavement (RAP). We haul RAP back to the plant, crush oversized chunks, and blend it into new hot-mix or warm-mix designs that meet Superpave gradations. This closed-loop process reduces virgin aggregate demand and cuts binder costs by re-using the bitumen already in the mix. Asphalt contractor Lebanon has demonstrated on several county projects that mixes containing 20 – 30 % RAP consistently pass Hamburg wheel-track and indirect tensile tests, showing that recycled material can match-or exceed-virgin performance.
Recycling also lowers the energy intensity of paving because less fuel is needed to super-heat virgin aggregates. By tracking RAP tonnage and mix performance, we provide municipal engineers with hard data that supports sustainability metrics and grant applications. Excess millings can be repurposed as shoulder aggregate, temporary patch material, or base for gravel lots, offering a cost-effective solution for blacktop repair on low-volume roads. Even small jurisdictions benefit: RAP piles become a ready supply of stable, well-graded material for winter pothole repairs when hot-mix plants are shut down.
Depth and Gradation Control
Modern milling machines use automated sensors, string lines, and even 3-D total-station guidance to hold an exact cut depth—whether we are correcting a ⅜-inch rut or shaving a full 2 inches ahead of a structural overlay. Cutter spacing and rotation speed affect the gradation of the RAP: finer chips are ideal when millings will be placed as surface aggregate, while coarser chips feed the asphalt plant’s RAP collar efficiently.
Paying close attention to these settings helps us minimize passes, conserve fuel, and leave a cleaner texture for the tack coat to grip. As a bonus, crisp texture lets our line-striping paint sit flush, improving visibility and extending striping life. We sync depth control with survey data so the finished grade aligns with curb reveals and driveway connections, minimizing post-pave adjustments and resident complaints. Continuous monitoring of tooth wear, conveyor speed, and drum temperature keeps production steady and prevents costly surprises mid-shift.
Benefits Over Full Repaving
Choosing milling over full repaving delivers several advantages for a city budget:
- Speed – We can mill and pave a lane-mile in a single shift, limiting detours and emergency-vehicle delays.
- Cost – Milling removes only distressed layers, trimming tonnage by 30–60 % compared with full-depth removal.
- Utility protection – By staying above the base, we avoid disturbing manholes, valves, and buried utilities.
- Design flexibility – We can feather edges or build crowns to fine-tune drainage without new grading work.
Because the remaining pavement structure is reused, milling is an ideal step in staged asphalt resurfacing programs that stretch limited capital over more lane-miles each season.
Cost and Environmental Impact
Public works budgets feel the squeeze of rising material prices and tighter emissions targets. Milling paired with a 1½-inch overlay typically runs about 40 percent cheaper than full reconstruction once shorter closures, reduced flagging hours, and lighter traffic-control setups are included. Environmentally, milling slashes greenhouse-gas emissions by trimming haul distances and lowering demand for virgin asphalt cement, which carries a steep carbon footprint.
Below is a quick snapshot of the sustainability gains cities can log when they pivot from full-depth removal to milling and overlay:
- 30 – 50 % less diesel burned thanks to fewer inbound and outbound truckloads.
- Up to 20 % burner-fuel savings when warm-mix additives drop drum temperatures.
- CO₂ reduction credits for every ton of RAP (Reclaimed Asphalt Pavement) reused in new mix designs. Read more here.
- Lower landfill burden because millings return to the roadway rather than the dump.
These metrics help municipalities hit green-roads certification targets while demonstrating responsible stewardship of taxpayer funds.
Wrapping Up
As city maintenance teams, we must balance durability, budget, and sustainability each time we repair a road. Asphalt milling lets us recycle existing materials, restore ride quality, and prepare surfaces for quick overlays or protective sealcoating-all in a fraction of the time and cost of full repaving.
By weaving milling into pavement-management plans alongside routine sealcoats, parking-lot striping, targeted crack sealing, and broader roadway rehabilitation initiatives, we keep our network safer, quieter, and more resilient for the traveling public. Staying committed to these best practices ensures that every ton of asphalt we place serves the community efficiently and responsibly-today and for decades to come.