The job of the Royal Engineers is to restrict the enemy's ability to advance, while also allowing friendly combat forces the freedom to maneuver as necessary. Other tasks undertaken are bomb disposal, the construction of fortifications, runways, roads and bridges and the improvement of existing infrastructure to support operations – such as improving existing roads for logistic convoys. To achieve this, the Royal Engineers operate a large and diverse fleet of vehicles. At present, the C vehicle fleet is provided by a private finance initiative (PFI) and consists of some 2,500 vehicles of over 160 types of "earthmoving plant, Engineer Construction Plant (ECP) and rough terrain Materials Handling Equipment (MHE)".