Different countries deal with this problem in different ways. Roads in the Netherlands have changed dramatically in recent decades. This is due to systematic focus on reducing accident rates, improved standards for road construction, and the roll out of traffic measures to reduce risk; including some of the strictest speed controls in the world. It works.

Bureaucracies are really good at data driven improvements, once they are tasked and empowered to do so.

Here's a list of measures that I know of that I would say are somewhat unique to the Netherlands compared to Germany where I currently live.

- two lane 100km roads now have colored green lines in the middle with white dashed lines on both sides of that green line. This creates a relatively wide area in the middle that is a bit of a neutral zone. This discourages cars from crossing that divider and doing things like driving close to or slightly across the line with half a tire. Reason: these roads are dangerous. Head on collisions at high way speed are usually bad news.

- Generally, overtaking on two lane roads is discouraged and limited to zones that are very clearly marked. You can expect traffic cameras near these zones too. Reason: people are stupid and overtaking cars on two lane roads at high speeds is a recipe for lethal accidents.

- more colored asphalt is used to separate bike lanes from normal lanes. Wherever bike and car traffic mixes, you'll find clearly marked parts of the road for bikes to use. As well as typically, reduced speeds. Reason, when bikes are involved with traffic accidents, the fatalities are significant. So, reduced speed and better separation, reduces the accident rate.

- A lot of country side roads have reduced speed limits. a lot of 80km (default max speed outside of cities) roads have been downgraded to 60km. Reason, narrow roads and high speeds cause lots of accidents. Speeds are clearly indicated both with signs and lettering on the road.

- Traffic cameras are used on all types of roads to enforce speeds in addition to moving speed checks. They are absolutely merciless. 1 km above the limit will cost you. People still speed but a lot less and compared to Germany where people will casually drive 70-80km/hour in places where you are supposed to drive 50km/hour,the difference is huge. The net result is that by and large, traffic seems to stick to the limits. Locals usually know where the cameras are and might risk going a few km over. But most chicken out and drive 45-49 km/hour. Better 2 km under than 1 km over. Those fines are not fun.

- Lots of roads in cities and villages are limited to 30 km/hour. Basically anywhere bikes and cars mix on the road. The default is 50 km/hour.

- Lots of crossings have been replaced with roundabouts. Remaining ones will have traffic lights or at least clearly marked right of way.

You get the point here. This is just a short list. This is a bureaucracy being systematic about rolling out measures that work just working the numbers and statistics. Every accident is analyzed and reported. Hotspots for accidents are prioritized for fixing. Traffic deaths are down by double digit percentages since 2006. And they were relatively low to begin with.