http://www.bigredcollective.com/corduroy-road-1
This leads us into the need for sturdier roads.
While these were certainly less effective than the paved roads we saw in Ur and the Indus Valley Civilization, in Glastonbury, England we start to see corduroy roads circa BC 3300.
Courduroy roads are roads built by joining together logs and are typically used for crossing shallow bodies of water, flattening dips in paths, or muddy areas.
Coruroy roads improve roads slightly, but are a hazard to heavy animals such as horses or oxen as the logs shift under weight.