What's under a Maryland Heights driveway
The floodplain on the west side is low ground, and the county's upland soils formed mostly in loess. The county soil survey says local roads on many of them need adequate base plus ditches and culverts for low strength and frost action. We keep water off the subgrade and compact the base in layers.
Bids are only comparable when they spell out the same things: base depth, compacted thickness, how edges are finished, and where water is meant to go. Ask for those before you pick a number.
Compacted asphaltTypically 2 to 3 in. for a car drive
Stone baseTypically 4 to 8 in., compacted
Drive on itUsually 2 to 3 days, longer in heat
First sealcoatTypically 6 to 12 months after paving
Typical ranges. Your Maryland Heights estimate is sized to the soil, the traffic and the drainage on your property.