Arriva
fitted particulate filters to the exhausts of 89 city buses. This reduced
emissions of hydrocarbons and carbon monoxide by 90% and particulates by 95%.
The potential for using new, cleaner diesel fuels within the bus industry
was also assessed. Information on clean fuels and vehicles was made available
from the EcoTravel Information Bureau and six electric / hybrid buses were
introduced onto a new city centre route all as part of the CATCH project.
The CATCH trials have provided a useful demonstration of the potential capabilities of hybrid buses. A total of 6 hybrid buses were introduced onto the City Centre route designed to link several regeneration areas, Liverpool's main shopping centre and main transport nodes, thus improving accessibility within the city centre.
The hybrid buses operating in Liverpool represented the first fleet of its kind in the UK. T he lack of other production orders for manufacturer, due to the hiatus in the market, has meant that the CATCH project's order of 6 vehicles was the sum total of their production in this period. As a result, the CATCH hybrid buses represented all of the product development work in taking the vehicles from prototype to a pre-production model. This product development required significant management time and maintenance support and caused more operational inconvenience than would have been expected with the purchase of a conventional vehicle.
Our demonstration has identified nothing which fundamentally stands against the concept of hybrid vehicles, but has identified several issues which hybrid vehicle manufacturers must overcome if hybrids are to develop into a part of the mainstream bus fleet. As a result, it is clear that more development and evaluation work will be necessary to help the product develop from a niche market with small, one-off orders to a larger, more continuous production base.
The detailed findings from the demonstration of particulate traps on buses in Liverpool have been evaluated in chapters 4 and 5 of the CATCH Evaluation Report .
