Commissioners debate gravel purchases and chip‑seal strategy for county roads

Road and Bridge staff reviewed recent gravel purchases, price projections and the mix of suppliers, and commissioners discussed whether to continue using chip seal on low‑volume roads or to convert more corridors to hot‑mix asphalt.

Staff reported that last year Miami County purchased 93,665 tons of AB3 rock for about $1,093,000 (average $12.13/ton). For 2025 staff projected a 5.4% increase in gravel price, to an average of $12.78 per ton; a $1.1 million gravel budget at that rate would buy roughly 86,071 tons. Staff said a target of 100,000 tons would require roughly $1.3 million at current projected prices.

Eric and other staff identified the county’s three rock suppliers as Midstates (northwest corner near Edgerton), Ham’s (Quick Creek, northeast) and the Old Block Quarry (central east). Staff explained the county’s typical AB3 mix and said some localized use of other mixes (for mud spots) may be appropriate, but the county will not place a clean rock on top of gravel roads because of safety concerns.

Commissioners debated the long‑term role of chip seal. One commissioner said chip seal had its time but opposed continuing to build “chip‑and‑seal” corridors that later require frequent maintenance: “I would never vote for another chip and seal road. It’s either gotta be a true asphalt corridor or gravel road from this point on,” the commissioner said. Other commissioners said upgraded chip‑seal specifications (bigger chips and thicker oil like were used historically) could yield longer life and reduce crack sealing frequency, but staff cautioned about supply and dust issues with larger chips and recommended investigating washed chips or alternative oil blends.

Staff noted the county includes chip‑seal roads in its 335‑mile count of hard surface roads and that choices about which chip‑seal sections to convert to hot‑mix asphalt should be part of a corridor prioritization exercise tied to traffic and strategic growth areas.

The commissioners asked staff to bring back comparative cost estimates for higher‑quality chip seal applications versus hot‑mix overlays and to provide a breakdown of how many miles of the county’s hard‑surface network are chip seal and how many have never been full hot‑mix overlays.