Types of Road Surfaces

Hot mix asphalt


This is the most common road surface. It is used on all new roads, roads throughout developments, mainline roads, and highways.

The typical county residential roadway section is 4" of asphalt placed over 8" of stone. The typical county business roadway section is 5" of asphalt placed over 10" of stone.

When the road needs to be resurfaced, 1-1/2 inches of asphalt is placed over the existing road. This surface usually lasts 15 to 20 years.
Hot Mix Asphalt Close Up

Tar and chip


These roads are constructed by Harford County's Highway Maintenance and are found mostly in rural areas of the county.

Tar is placed on the road and stone is spread over the tar to provide a wear surface. These roads are usually maintained every five years.
Tar and Chip Close Up

Earth roads


These consist of dirt and gravel and they have very little traffic. When traffic increases or at the request of residents, these roads may be converted to tar and chip surfaces.

Frequency of maintenance depends upon conditions such as traffic and weather.
An earth road close up

Road Pavement Details

A graphic illustration of different road types.