Some governments consider roads as critical for their competitive position. Without a good road-network, the Netherlands would loose their position as transport country and the work generated by the Rotterdam Harbor would dry up.
Accidents cause road-blocks which cause traffic jams. Hundreds of people in traffic jams idling costs enormous amounts of lost productivity and is bad for GDP.
With a social system ensuring everybody for health-case and a decent life standard when not able to work, avoiding accidents becomes an economical question.
I'm not stating the government does take all this into account, but at least the importance of a good and safe road-network for the whole country is understood.
Note, roads are not only there for those driving a car. Even if you do your groceries walking, ask yourself how your food ended up at the store. Ask yourself how the Ambulance managed to come to you when you need it.