The general use is to switch to high beam lights when low beams are not giving you the visibility that you need. This means you won’t be needing high beams while on a well-lit city street. Moreover, city streets are more often than busy and filled with cars. Using high beams might be a huge inconvenience for other drivers on the road and is actually a safety hazard. In places, you might even get fined for using high beams. You should also not use high beams if you are driving directly behind another car because this will make it difficult for that driver to use the rearview mirror.