Trucks are highly flexible vehicles able to carry almost every types of cargo over short to medium distances.. Package trucks are commonly used in urban freight distribution since they carry a variety of cargo (in boxes or pallets) servicing a fluctuating demand. Less than truckload (LTL) carriers usually consolidate and deconsolidate loads coming from different customers, which is common in the parcel carrying business. Truckload (TL) transportation carries large volumes that have been broken down into the largest possible truck load unit; several truckloads are required to fulfill an order. The variety of modal options is related to the technical requirements to carry specific cargoes such as bulk, liquids or containers. Trucks using chassis are able to carry domestic (usually 53 feet in North America) and ISO containers (20 and 40 feet).