vehicles were destroyed in World War II. When American troops began to leave the Philippines at the end of World War II, hundreds of surplus Jeeps were sold or given to the Filipinos. An American soldier named Harry Stonehill was involved in the disposal of military surplus, and reportedly created a black market for the surplus including jeeps. The Jeeps were stripped down and altered locally: metal roofs were added for shade; and the vehicles decorated in vibrant colours with chrome-plated ornaments on the sides and hood. The back part was reconfigured with two long parallel benches with passengers facing each other to accommodate more passengers. The size, length and passenger capacity has increased as it evolved through the years. In assembly-built jeepneys (notably those built by Sarao Motors and Francisco Motors), the passenger capacity reached a maximum of fourteen to eighteen (including two up front). These high-capacity jeepneys were the first versions to be referred to as "Public Utility Jeepneys" (PUJ) or "passenger-type" jeeps. The non-extended, original-seat configuration jeeps were labeled "owners", short for "owner-type" jeeps, and are used non-commercially. To distinguish it from those used as public transportation, the term "owner" is used. The original jeepneys were refurbished military Jeeps by Willys and Ford. Modern jeepneys are now produced with engines and other parts from Japan or South Korea. The jeepney rapidly emerged as a popular and creative way to re-establish inexpensive public transportation, much of which had been destroyed during World War II. Recognizing the widespread use of these vehicles, the Philippine government began to regulate their use. Drivers now must have special driver's licenses. Routes are regulated and prices are fixed fares. Illegal (unfranchised) operators are referred to as "colorum" operations. Jeepneys have been reported to be exported to Papua New Guinea to replace buses and vans that are too costly to import. 4,000 jeepneys were exported to Papua New Guinea in 2004 with considerations to export them to Guam, India and Vietnam. Recently, the jeepney industry has faced threats to its survival. Most of the larger builders have gone bankrupt or have switched to manufacturing other products, with the smaller builders forced to go out of business. Passenger jeepneys are also facing increasing restrictions and regulations for pollution control, as they consume much fuel. A 2017 study published in a Metro Manila newspaper compared the fuel use of a 16-passenger jeepney to a 54-passenger air-conditioned