A £20m investment from Nottingham City Transport is going towards the development of the bio-gas buses that will more than double in size.
With 53 bio-gas buses already on the streets of Nottingham, the further £1.12m investment from OLEV (Office of Low Emission Vehicles) is allowing another 67 buses to be added to the fleet.
This development will ensure the bio-gas double deck buses will reduce the emissions and withdraw the oldest buses (pre-2011).
The bio-gas buses currently run through areas such as West Bridgford, Beeston and Mapperley.
Funding from Nottingham City Council and Nottinghamshire County Council will allow the company to also fit exhaust treatment systems to its existing younger diesel buses.
67 buses will be on Brown Line 17 to Hucknall Road, City Hospital and Bulwell in April.
They hope to have all 120 bio-gas buses running by November.