I sometimes carry my wallet but many times don't - it depends on the kind of ride I'm doing and where I'm going. Same with my cell phone. Same with any extra cash. I can't imagine why anyone would need to have a DL on them when riding a bike. I keep it and my debit card in my wallet and if I'm going somewhere where I might want to use my debit card, then my wallet (with DL) comes along for the ride.