There was a stretch of U.S. highway in my hometown that was built with concrete slabs. It is actually very durable and lasts for decades without need of repair, but it is also done in segments and the segments shift and create unevenness over time. Its not a terribly bumpy ride but it definitely isn't smooth like fresh asphalt. Anyways, at some point they grinded off a small layer of concrete and paved over the top with asphalt. When asphalt is fresh its definitely a more enjoyable drive.