Since January 2007, all
new heavy duty vehicles are required to comply with Euro 3 while
new motorcycles should comply with regulations for powered two
and three-wheeled vehicle (97/24/EC) which requires CO2 emission
to be no more than 3.5 g/km, and HC + NOx emission of no
more than 1.8–2 g/km [69,70]. All in-use vehicles are required to
renew registration annually. In 2005, a voluntary labelling program
was launched by the Pollution Control Department to mitigate
CO2 emission and reduce fuel consumption and implemented to
National Energy Policy Office as voluntary labelling Program in
2006 [12].