A wide range of sensors are developed for autonomous vehicles in order to ensure safe driving conditions by detecting any relevant objects in the road environment. The sensors, cameras, Lidars and radars, cover a wide range of wavelength, ranging from visible, Near InfraRed, Short Wave InfraRed and beyond for high frequency radars. For Lidars technology, a single wavelength scans the environment. To get the most efficient detection, the choice of the wavelength must be optimized. Knowledge of the spectral reflectance of road objects at the chosen wavelength is a key point. An original application of reflectance measurement technics is proposed to characterize road objects in the range of wavelength between 350 to 2450 nm. This investigation could lead to the definition of reference tests including a physical characterization of the environment.