[mopsi]

Many places in the world already have reflectors installed into all major and many minor roads. Seems like a reliable and very cheap way of detecting lane geometry. https://www.worldhighways.com/_resources/assets/inline/custo...

Snow isn't a problem either, because reflectors can be (and often are) mounted onto plastic poles. https://c7.alamy.com/comp/EC79CD/reflector-signal-white-post...