Dispersal
Norway maple reproduces by seed, which it produces in copious amounts. The winged fruits (samaras) are distributed by the wind; the seeds germinate readily, even in dense shade, and grow quickly when young.
Problems
Many of the features that made this a desirable tree to plant by roadsides are also why it has become invasive. Being hardier than many native tree species has allowed it to out compete and thrive. The ability of this species to grow in deep shade makes it particularly threatening to native forest habitats. Like many invasives, its ability to grow quickly gives it the upper hand when gaining control of an area.