Driving to Perfection

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All Roads Lead to Rome

Romans were the preeminent road builders of the ancient world. The illustration shows a cross-section of a typical Roman road. A stone footing, compacted gravel or rubble interior, and a cobble surface remained firm in wet weather but would not turn to dust on dry days. Sides were ditched to carry off water, and culverts and bridges were built over dips to carry water under the road. Cobble surfaces were fine for foot-Legions but too bumpy for wheeled vehicles, and construction was (forced) labor-intensive. In the 19th century, J. J. Mac Adam designed British roads with smoother surfaces that could be built quickly and economically by freemen and draft animals. Not oiled or asphalted like modern macadam roads, the top was of fine crushed rock that compacted with use to shed water, but would not become too dusty in the summer. The road was domed and ditched to carry off rain. Although modern highways have a deeper multi-level foundation and solid asphalt or concrete surface, they are really not much different from Mac Adam's original design.

Modern-Day Drives

For your own drive, it's doubtful that you'll want to bury stone blocks Roman-style. You'll want to adopt Mac Adam's formula of digging out topsoil and laying in a well-ditched, contiguous-ribbon wedge of adhesive soil and rocks, compacted to repel water and topped so it won't grind to dust.

I'll warn you now that this article covers only drives of forgiving natural materials, which homeowners can design, build, and maintain at reasonable costs. I've seen too many amateur-laid thin, unreinforced concrete drives crack, and too many asphalt drives go gummy and sprout grass because they weren't rolled and the underlayment wasn't salted. Oh, there is a cold-set, water-mix asphalt you can buy in drums or pickup-truck lots, but it is suitable for walkways at best. Preparing a rolled gravel surface for hot-top or laying forms for concrete — and then trying to lay transit-mixed concrete or stick-to-everything-but-the-gravel asphalt so it turns out uniformly smooth — is no job for an amateur. If you want an asphalt or concrete drive, save your pennies, look in the Yellow Pages ...and have pros do the whole job.

Time to Start Planning

The first step is to design (or redesign) your drive so that it will handle modern vehicular traffic. The drives of old country homes were designed for horses and wagons. They are narrow, have tight curves, and negotiate hills too abruptly for modern vehicles, so these old drives need to be broadened and have their transitions eased.

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