At what maximum speed may a light quadricycle travel outside built-up areas?

For three-wheeled vehicles and non-light quadricycles, on any type of paved road outside built-up areas where their circulation is permitted, a limit of 70 km/h applies.
A light quadricycle is considered a 4-wheeled moped. Mopeds are by design unable to exceed a speed of 45 km/h, and therefore that is the limit they must comply with.