However, increasing international fuel price,
limited domestic availability of these fuels and the concerns
of cleaner environment in the country have prompted
consideration of various alternative technologies (e.g.,
biofuels, hybrid engines, natural gas, fuel cells and electric
vehicles). Indeed, although relatively small in the share,
biofuels- and natural gas-based vehicles are already
introduced in the country. Fig. 5 depicts the relative share
of penetration of conventional, efficient conventional and
new vehicle technologies during 2000–2050 under the
reference scenario. As seen from Fig. 5, the penetration
of conventional efficient vehicles is estimated to be about
4.8% of total vehicle technology types in 2010 and
gradually decreases thereafter. Among the technologies,
the share of hybrid and fuel cell vehicle stocks together in
total vehicles types is estimated to reach 81% in 2050,
followed by conventional vehicle stocks (8%), electric
(6%), conventional efficient (4%) and natural gas vehicles
(0.4%). Over the study period, the results show that
conventional vehicles would gradually be replaced by
efficient conventional vehicles and these vehicles in turn
would be gradually replaced by new vehicle technologies
such as hybrid and fuel cell vehicles.