Yes, boats and trailers can be towed on The Toll Roads.
If you don't have an account, pay toll(s) online at TheTollRoads.com or via The Toll Roads app within five days before or five days after driving. You will need to know both the vehicle and trailer's licence plate numbers and the number of axles.
California State Highway laws also apply on The Toll Roads, therefore any vehicle pulling a boat or trailer must follow the same rules and regulations as on the regular highways.
Please note, boats and trailers cannot be towed on the 91 Express Lanes, the tolled lanes in the median of the 91 Freeway. The 91 Express Lanes are owned and operated by the Orange County Transportation Authority and Riverside County Transportation Commission.