Or non-newtonian fluid speedbumps that are soft when hit with light stress and hard when hit with a lot of stress https://www.jalopnik.com/these-speed-bumps-on

Or non-newtonian fluid speedbumps that are soft when hit with light stress and hard when hit with a lot of stress https://www.jalopnik.com/these-speed-bumps-only-turn-solid-if-you-are-driving-to-1851545857/ https://www.jalopnik.com/these-speed-bumps-only-turn-solid-i... Probably highly temperature dependent or get stabbed with a knife in 2.3 hours depleting its reserve of non-newtonian goo.