FTA's comments follow the release of the final figures from the Government's Low Carbon Truck Trial which put more than 350 gas-powered HGVs on UK roads and supported over 15 public refuelling stations.
The trial has given industry the opportunity to test alternative fuels to diesel: however, operators believe that alternatively-fuelled truck numbers will decline if further financial support is not provided to help bridge the gap to large-scale commercialisation.
Rachael Dillon, FTA's Climate Change Policy Manager, said: "The new Low Emission Freight and Logistics Trial announced over summer 2016 and the extension of the plug-in vehicle grant to vans over 3.5 tonnes were welcome moves to help the industry reduce its environmental impact.
"However, the majority of Government funding to date has been allocated to cars. The UK gas truck fleet makes up just 0.2 per cent of the overall truck fleet and there is potential for significant progress to be made in increasing these numbers. However, if the Government is serious about increasing the presence of 'green' trucks on our roads, it must ensure that it continues to help provide facilities and incentives for operators to use them."
As operators seek to achieve further significant reductions in carbon emissions and to improve air quality performance beyond Euro VI in the 2020s, FTA asserts that they will require financial support to adopt greener fuels and low carbon technologies, alongside government policies that support alternatives.
The industry believes that high costs of vehicle conversions or purchasing ultra-low emission vehicles plus a lack of public refuelling infrastructure are significant barriers to putting greener trucks on the road.
Ms Dillon added: "It is crucial that renewable fuels such as biomethane can be utilised in trucks to bring bigger emission reductions, especially when there are limited options for heavier vehicles to decarbonise. Government must incentivise the production of biomethane for use as a road transport fuel rather than through the heat sector."
Additionally, DfT also released results of Emissions Testing of Gas-Powered Commercial Vehicles, which recommend that Government continues to support the development of gas vehicle infrastructure and gas powered vehicles.