155. Transport PPP may be susceptible to the distortions caused by fuel subsidies. Many MENA countries continue to heavily subsidise motive fuels, diesel and gasoline. Where these fuels form a major input cost for competing forms or modes of transport, it may be difficult for a PPP to compete. For example, a rail transport project may not be viable in the face of a trucking sector that benefits from heavily subsidised diesel. Such subsidies are also problematic from an environmental and fiscal policy perspective. Reforming long-standing and politically popular fuel subsidies may be very difficult but governments should understand that transport sector PPPs may not be feasible in the absence of such reform.