What is the requirement concerning which lanes to use on a multiple lane highway?

On a multiple lane highway, drivers are generally required to use the right lanes for slower speeds and for merging, while the left lanes are typically reserved for passing and faster-moving traffic. Many jurisdictions mandate that vehicles should keep to the right except when overtaking or passing another vehicle. It's important to follow local traffic laws, as regulations may vary by region. Always be aware of signage indicating lane usage rules.