The phrase "speed bumps" refers to raised structures on roads that are designed to slow down vehicles by creating an obstacle or a small bump. Full definition
I'm happy to report that it's some serious fast - paced fun, but there are a few speed bumps in the way of making it a totally amazing racer on PC. (gamingenthusiast.net)
But these could be just speed bumps on the path to even more deep drilling. (discovermagazine.com)
Even the happiest families hit speed bumps along the way. (theravive.com)