The rules when using dash cams in different states vary considerably. The simplest and most logical rule is about positioning, requiring that a dash cam not obstruct the view of the driver. This rule explicitly applies in Alaska, Arizona, California, Florida, Hawaii, Illinois, Indiana, Iowa, Kansas, Kentucky, Maine, Maryland, Missouri, Nevada, North Carolina, Utah, and Vermont. However, it’s a logical rule you should follow everywhere. Some of those states have specific rules about camera placement beyond ensuring it doesn’t obstruct your view. In California, for example, a dash cam has to be mounted in a seven-inch square on the lower corner of the windshield, away from the driver, a five-inch square in the corner nearest to the driver, or in a five-inch square in the upper-center. Meanwhile, in Illinois, a dash cam must be in the bottom corner of the windshield on the passenger side. In some states, like Alabama, Delaware and Louisiana, the dash cam can’t even be mounted on the windshield at all, while states like Pennsylvania and Minnesota forbid having anything mounted on a windshield, period. In these cases, it has to be mounted on the dashboard. So, it’s important to check positioning rules in your state.

There are also size requirements, with most states requiring that a dash cam be smaller than five inches. Some states, like Hawaii, permit dash cams as large as 7 inches, while in Indiana, it can be no more than 4 square inches.

When it comes to use, in 13 states, you can’t record conversations in a vehicle unless every passenger in it consents. The 13 states where this two-party or all-party consent rule applies are California, Delaware, Florida, Illinois, Maryland, Massachusetts, Michigan, Montana, Nevada, New Hampshire, Oregon, Pennsylvania and Washington. Other states have rules about recording that you should pay attention to as well. In states like New York and many others, recording video from a dash cam is fine. But audio conversations are not permitted without at least one party’s consent. This might not matter much for family road trips, but it’s something to consider if you’re traveling with colleagues, carpooling with others outside your family, or are a ride-share driver.