In many states a carpool or HOV violation results in a ticket and points for a moving violation. Generally, most insurance companies would consider this to be a minor violation and if it is your first ticket in some time might not raise your rates. If you have multiple tickets or other incidents it can make your insurance rates to rise. There is a website called Hovworld.com that actually lists in which states this is a points or non-points violation.
If it is a points violation in your state you might want to see if your state allows you to take traffic school. There are certain states in which you can request to take traffic or driving school and get your HOV or carpool ticket points taken off of your driving record. This may be a choice you would want to take advantage of.