When you need to move something truly large, an RGN trailer is the answer. RGN means Removable Goose Neck. The trailer sits low to the ground and actually separates into two pieces. Once separated, heavy machinery can be driven straight onto the lower deck and secured with chains and binders.
RGN trailers can be used for more than bulldozers, though. Have an air conditioning unit that's 11 feet tall? Put it on an RGN and maintain legal height, avoiding the extra expense and hassle of oversize permits.