Department investigates variable performance but Transport Scotland backs technology and continues to fund conversions. Rhodri Clark reports
A bus in Glasgow. Transport Scotland is continuing to fund retrofitting through its Bus Emissions Abatement Retrofit (BEAR) programme
The DfT has defended pausing England’s bus retrofitting programme while it investigates variable performance. Faced with the same evidence on performance, Scotland is continuing to fund conversions to bring old vehicles into line with newer emissions standards – and says recent research shows the technology contributes significantly to cleaner air.
The DfT paused its funding for further retrofitting of buses in April after evidence emerged that the technology may not be delivering the expected reductions in nitrogen oxide emissions. It is investigating the issue and talking to retrofit suppliers about possible causes and solutions.
The situation has caused further delay to the introduction of Greater Manchester’s Clean Air Zone, as well as delaying bus conversions for various areas of England. So far, the DfT has provided nearly £170m to Greater Manchester to help reduce nitrogen dioxide levels, of which approximately £150m was spent on retrofitting 1,153 buses before the programme was paused.
A DfT spokeswoman said: “We work closely with local councils to help them improve air quality, including with using technology to help improve bus emissions.”
The DfT had always intended to undertake in-service monitoring to understand the effectiveness of retrofits funded by the UK Government. “This was accelerated when issues identified in Scotland suggested that retrofitted buses may not be having the anticipated impact on real world NOx emissions,” said the DfT. NOx (nitrogen oxides) refers to nitrogen dioxide (NO2) and nitric oxide, both of which are produced when fossil fuels are combusted.
Evidence has shown variability in the performance of the retrofit technology, and the government has taken a decision to pause further funding whilst further investigation is carried out
“Evidence has shown variability in the performance of the retrofit technology, and the government has taken a decision to pause further funding whilst further investigation is carried out,” said the Department.
Transport Scotland told Passenger Transport last week that it was continuing to fund retrofitting through its Bus Emissions Abatement Retrofit (BEAR) programme. “Recent research shows that exhaust emission retrofits fitted under the BEAR programme do generate a significant improvement in vehicle emissions (NOx and particulates) and will therefore be having a direct and positive effect on urban air quality compared with non-retrofitted vehicles,” said a Transport Scotland spokesman.
“BEAR retrofitting, along with other transport initiatives, has helped to improve air quality in some our most polluted streets ahead of the wider enforcement of LEZs [Low Emission Zones]. BEAR retrofit buses are subject to monitoring and evaluation to ensure that satisfactory in-service performance is achieved as part of the conditions of award.”
After receiving Scotland’s defence of retrofitting, Passenger Transport asked the DfT whether it had over-reacted to retrofit under-performance which was only marginal in the context of the overall programme, and whether the effect of its on-going pause would be a reduction in total DfT retrofit funding, because more old buses would be replaced with new ones over time.
It would be premature to make a final decision on future funding of retrofit ahead of the results of that investigation
The DfT responded: “It would be premature to make a final decision on future funding of retrofit ahead of the results of that investigation.
“Bus retrofit is one of a number of measures used by local authorities to improve air quality in cities across England. The NO2 programme works closely with local authorities to agree specific measures appropriate to their circumstances. Government remains committed to working closely with programme local authorities to achieve compliance with legal NO2 limits in the shortest possible time.”
As the investigation has proceeded, the DfT has shared information and data on bus retrofitting with Greater Manchester so that the city region can factor them into its analysis. “We are continuing to engage closely with them on this issue,” said the DfT.
The full story appears inside the latest issue of Passenger Transport.
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