K
If what my man at Michelin says is true and I've no reason to agrue, your Dunlop will also be road legal. He stated that the FIM will not accept a trials tyre that is not fully road legal as to comply with the regs the tyre should be suitable for use on the trials where road work is included. He pointed out that any markings to the contrary on the tyre wall should state where these restrictions apply. North America was mentioned as they can only be used there for limited milage and at certain pressures. (though knowing the USA this may change state to state).
Look out for an E or e marking on the tyre that means its been accepted for European road use.
My garage questioned the tread patern too but the regulation states that the distance between the nipples cannot be bigger than the nipples themselves so its OK. Well on bikes at least, I wouldn't like to meet a girl who met this requirement.