What is the Average thickness of ashphalt on city roads and freeways?

Answer 1

4" city, 6" highway. The actual road bed, of which asphalt is only the top layer, is usually about 2 feet, and this varies based on load conditions, and soil.

Answer 2

Rough guess (based on direct observation and having some friends in the road-construction business):

City: 8 - 12"
Freeways (US): 24"

Hopefully there will be a road-construction specialist who will read and answer the question to give a better (more accurate) answer.

EDIT: for the city pavement, I am figuring on several years worth of resurfacing and overpaving that adds up to almost 1 foot of asphalt.

I have personally seen the finish layers on some interstate freeways, where they actually lay a couple of feet of asphalt. Whether that is standard/average, or not, I don't know.

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