NOVELTY - The system has a set of spaced transverse channels formed under a road extending across a lane i.e. fast lane (2), of the road. A cylindrical metal friction roller-power generator (1) e.g. electrical power generator, is positioned in rotary axis transverse to the road and extended across the lane of the road. An underground containment system (20) houses the transverse channels and the roller-power generator. A power conversion unit connects the roller-power generator to a storage battery and/or a power inverter to supply electricity to a power grid.    USE - Underground roller system for generating useful clean electrical power to be transmitted to a storage battery or converted from direct current to alternating current by an inverter and directly sent to a power grid, from passage of a motor vehicle e.g. light car and 100000 pound lorry, over a roadway surface in an area of high traffic volume. Can also be used for generating useful clean electrical power to be transmitted to an electrical device i.e. light.    ADVANTAGE - The roller-power generator efficiently produces a desired electric power output insitu in a better manner, and directly delivers electrical power for same number of roller revolutions with reduced frictional loss. The roller-power generator can be fabricated by using a set of optimal mechanical designs incorporated with a set of modern electrical generator designs to improve safety of the roller-power generator. The electric power is directly delivered to the storage battery or power grid without the need for an externally coupled generator, thus reducing the number of equipments and the number of moving parts used for power distribution. The system with environment-friendly design can be produced at low cost with high power output, underground containment, rugged strong construction materials, road surface compatibility, minimum number of components, minimum maintenance, convenient equipment installation and replacement, corrosion resistance and weather resistance such as heat resistance. The system has a polymer tread covering minimizing a bump to improve roller efficiency.    DESCRIPTION OF DRAWING(S) - The drawing shows a cross-sectional view of a cylindrical metal friction roller-generator including a set of spaced transverse channels embedded in a roadway.    Cylindrical metal friction roller-power generator (1)    Fast lane (2)    Polymer tread covering (11)    Air compression chambers (12)    Underground containment system (20)