The US Army's new medium brigades, using wheeled armored vehicles (LAVs, or Light Armored Vehicles) instead of tracked tanks and APCs of the heavy brigades, will cost much less to operate and maintain. The medium brigade will cost $4.7 million a year, versus $7.6 million for the heavy brigade. The wheeled vehicles are expected to be more reliable. Tracked vehicles travel an average of a thousand kilometers between breakdowns. The LAVs will travel over 2,000 kilometers. The LAVs will also be able to move along roads at a up to 100 kilometers an hour, about a third faster than tracked vehicles. This is an important feature in peacekeeping operations, where getting to a trouble spot fast is critical. Finally, the medium brigades won't need the 27 tank recovery vehicles and 132 tank transporters of the heavy brigade. Tracked vehicles last longer if you drive them to the combat zone on the back of a tank transport (a tractor trailer.)