Yeah, you read it right. We have laws for almost everything on our bikes. There are laws for exhaust, noise levels, handlebars, helmets and even mirrors.
Mirrors are obviously important, but so is turning your head to look before changing lanes. Mirrors have a limited frame of view and do not cover the entire blind spot area. Always turn and look. It takes a little effort, especially in full face helmets. But it takes a lot more effort to get out of a hospital bed after an accident.
As usual, there is nothing uniform about mirror laws from state to state or country to country. Yes, they can fine or even arrest you if your bike doesn’t conform to the state you just entered. The safe way is to have the stock mirrors on the bike as they are already approved. Stock mirrors? Not always cool and not always the best visibility.
State variations my include the number or mirrors required. This can actually be from zero to two. Yes, some states do not require a mirror. If you are in one of those, be aware when you ride into another state that the laws have changed at the border. If you are in a state that requires only one mirror, it usually must be mounted on the left side.
States may require a visibility range. For example, several states require the rider to be able to see a minimum of 200 feet behind them.
Some states have size requirements. You need a minimum amount of surface area for visibility. When customizing your bike, know this law to make sure your added expense isn’t a fine.
Sometimes, the toughest part of this is understanding the legal-ease they use. Often, motorcycles are lumped in with passenger vehicles and you have to look through an entire code to figure out what applies to you. A good resource for motorcycle laws is the AMA State Motorcycle Laws page. Take a look at the states you ride in. Above all, be safe. It matters.