This is not only road users: roadworks have restrictive speed limits, which are not taken down when there is no workforce out, to minimise risk to workers setting and unsetting limits, traffic cones etc. Things that in other countries would close a lane often close the whole road, again because of risks to road users and maintenance people.
This is of course great, but also very expensive - and I cannot shake the feeling that the UK loses so much money on this risk aversion that is actually causes more hazard due to underinvestment elsewhere. NHS is crumbling, the very safe roads take forever to navigate, introducing inefficiencies and starving the central budget of cash. GDP per capita has barely grown since 2008. Even a small annual boost would unlock a lot of cash for investment, in particular into NHS and saving lives.
It's like putting all your pension investments into bonds, because they are safer. But you swap market risk for the risk of not having enough cash when you retire.
But maybe it's easy to have this perspective because I have a desk job and commute by public transport.