It depends on what you are talking about for DOT. You could have DOT legal tires, which mean they are "legal" to drive on the street. And in the cases of some autocross tires, have just enough tread to be driven on the road even though they have a treadwear rating of 40 But basically DOT legal items are legal to be used on the road. Like most Altezza taillights they haven't been put through the process of getting them legal due to costs. Some companies have gone through the process, but then the price of those taillights increase.