Where can I find car ownership densities for the UK?
Car ownership levels are provided in the Regional Transport Statistics. This can be accessed from here.
Where can I find information on legislation governing car emissions?
A good reference is the Pollution Handbook produced by the National Society for Clean Air (NSCA). It provides a comprehensive overview of pollution control legislation in force, including that covering regulations on vehicle emissions. The NSCA website is www.nsca.org.uk
Where can I get traffic statistics by road class
Road transport traffic statistics can be downloaded from the Data Warehouse section of the NAEI website. Go to Data Warehouse ----> 4. UK Activity data ---->transport statistics -----> UK Vehicle fleet composition projections 2002.
How much CO2 is released per litre of fuel used by a car?
Ultimate CO2 (that is assuming that all carbon in the fuel is eventually converted to CO2) can be calculated from the carbon content of the fuel. You will first need to convert a litre of fuel into tonnes or equivalent. The carbon content of petrol is 0.855 Mtonnes per Mtonne of fuel whereas diesel has a carbon content of 0.857 Mtonnes/Mtonne. To convert from carbon emissions to CO2 you need to multiply by 44/12.
What does gram's/trip mean?
These are emissions relating to cold starts of engines. Trips basically means number of starts.
How do motorcycles and other PTW's compare with average family car in terms of emission performance?
Go to the Data Warehouse on the NAEI webpage (www.naei.org.uk). Then go to road transport emission factors. This spreadsheet should provide you with the information you need.
Where can I find the data on levels of pollutants emitted by buses and lorries in the UK?
Go to the data warehouse section of this website and then to UK emission factors - road transport emission factors. Information on emissions from buses in terms of grams per kilometre can be downloaded from this site. For details of total emissions in the UK please refer to the report section of the NAEI website and look at the annual NAEI report (UK emissions of air pollutants)
To produce the emission information for bus's and coach's what load factor (number of passengers) do you assume?
The emission factors provided on the NAEI website for road transport are independent of the number of passengers as they are per vehicle per kilometre. If you want to calculate an emission factor in terms of passenger kilometres I would suggest that you use the average loading as provided in the Regional Transport Statistics which is available for download from the DfT website.
| 
