The document discusses amendments to UN R149 regarding road illumination device requirements. Illuminance and light intensity requirements have been amended multiple times over 16 years. The basis for type approval was adapted to 13.2 volts, increasing required values by approximately 40 per cent. In the 01 series, maximum values at 50L increased by a factor of 4 to improve visibility and pedestrian recognition. On dual carriageways, headlamp illuminance should exceed 8 lx@25m in point E50R/L and 16 lx@25m in point E75R. On motorways, E75R should exceed 36 lx@25m with half those values in E50L. However, increased light intensity increases glare risk for oncoming vehicles, particularly with levelling changes due to load.