WASHINGTON, USA - Toyota chairman Takeshi Uchiyamada has challenged automakers to step-up sales of hybrid vehicles in the US, calling them "a long bridge" into the future.Uchiyamada, who pioneered the hybrid Prius, said: "I call on the industry to sell five-million hybrids in the US by the end of 2016. It's only when we put ourselves under the same kind of intense pressure we faced in developing the Prius that we can achieve great goals."That's what it takes. I want our industry to achieve this goal."‘MANY MORE GAINS'Uchiyamada forecast that hybrid vehicles would play a larger role than understood at the moment in the development of automotive propulsion systems. He was chief engineer of the team that developed the Prius, the world's first mass-produced petrol-electric hybrid, launched in 2007.Uchiyamada said: "Some people say hybrids such as the Prius are only a bridge to the future but we think it could be a long bridge and a very sturdy one. There are many more gains we can achieve with hybrids." Uchiyamada was "particularly excited" by a Toyota project developing a new hydrogen fuel-cell vehicle that would have zero emissions and eliminate some of the issues with electric vehicles, such as charging time and range.He noted the auto industry needed to gear-up to achieve the ambitious fuel economy standards established by US president Barack Obama's administration. As of March 2013, Toyota had sold five-million hybrid vehicles globally, including the Prius. ‘FOCUS ON THE US’Toyota operates 14 factories in North America which produce 70% of its vehicles sold in the USA. Uchiyamada said: "Right now our focus is on the US market." Toyota surged past Ford to claim second place in US sales in August 2013 as sales jumped 23% to 231 537, the automaker’s best month in more than five years. In early September 2013 a Toyota executive was upbeat about the company's US sales outlook after the auto industry exited a three-year slump amid the 2007-2009 recession.Toyota sales executive vice-president Bob Carter said Toyota expected to sell more than 2.2-million vehicles in the US in 2013, up from 2.1-million in 2012 and 1.6-million in 2011.A new Prius hybrid sedan will reach showrooms in 2015.