This is a phenomenon called risk compensation. The Wikipedia article (https://en.wikipedia.org/wiki/Risk_compensation https://en.wikipedia.org/wiki/Risk_compens

This is a phenomenon called risk compensation. The Wikipedia article (https://en.wikipedia.org/wiki/Risk_compensation https://en.wikipedia.org/wiki/Risk_compensation) covers the mechanism well, but misses one important thing - in every study that was ever done, the risk compensation effect was less than the safety effect introduced. E.g. the Golden Gate bridge barrier was a big increase in safety, and while people driving faster mitigates some of it it's still definitely an improvement. [I don't have data on the Golden Gate Bridge specifically, just using it as an example]