Sixty-per-cent of National Express West Midlands’ 1,600 bus fleet is now Euro 5 or 6, thanks to hundreds of older buses being fitted with selective catalytic reduction (SCR) systems and traps.
It takes a team of two engineers around six hours to fit a system, reducing emissions by up to 96%.
A video showing engineers retrofitting the systems is at https://www.youtube.com/watch?v=dRy0iKktUMg&t=1s
