Get matched with top asphalt driveway pros in Saint Charles, IA

Three inches is a great thickness for a residential asphalt driveway that sees minimal to moderate traffic from cars, SUVs, and pickup trucks. However, a thicker driveway can better withstand the weight of a heavier vehicle, such as a trailer or a recreational vehicle. If you drive a heavy vehicle on a thin driveway, you risk cracking and damaging it.

Asphalt and tarmac are not the same thing. Traditional tarmac, short for tarmacadam, uses tar as a binder to hold crushed stone together. Asphalt uses bitumen—a byproduct of crude oil—to bind aggregate. Though tarmac was once a go-to for roads, asphalt has become the modern standard. And these days, most surfaces referred to as “tarmac” are actually asphalt. So, while the names may overlap, the key distinction lies in the binder—tar for tarmac and bitumen for asphalt.

Building a road on a slope requires careful planning and will normally require a drainage system underneath to prevent flooding and damage to the road over time. Your professional may lengthen your road to create switchbacks if the slope directly to your home is too steep, as there are regulations for maximum road slope. The drainage system will help prevent runoff from the higher side of the slope from damaging the asphalt or concrete. Keep in mind that building a road on a slope isn’t a good DIY project, as a lot can go wrong.

There’s no single best asphalt grade—it all comes down to where and how it’s used. Highways and heavy-traffic roads need something tough, like polymer-modified asphalt (PMA) or Stone Matrix Asphalt (SMA). Local roads and parking lots rely on the Performance Graded (PG) system, chosen based on climate. A PG 64-28 mix, for example, handles a broad temperature range while simpler, more cost-effective mixes are typically enough for residential driveways. The best grade of asphalt depends on traffic, weather, and your budget, which is why a professional’s input is always a smart move before making a decision.