Motorcycles in your bus lane

Here's an interesting set of figures from 2010 about motorcycle emissions in bus lanes.
http://www.tfl.gov.uk/assets/downloads/PT-emissions-study.pdf

Bus lanes make motorcycles cleaner:

'Powered two wheelers using bus lanes where available emit an average of
between 0.5% and 9.0% less Carbon Dioxide than powered two wheelers using
general traffic lanes only;
• Powered two wheelers using bus lanes where available emit an average of
between 0.5% and 10.0% less Oxides of Nitrogen than powered two wheelers
using general traffic lanes only;
• Powered two wheelers using bus lanes where available consume an average of
between 0.4% and 9.0% less fuel than powered two wheelers using general traffic
lanes only;
• Powered two wheelers using bus lanes where available emit an average of
between 100% and 500% less Carbon Dioxide than petrol cars using general traffic
lanes only;
• Powered two wheelers using bus lanes where available emit an average of
between 50% and 550% less Oxides of Nitrogen than petrol cars using general
traffic lanes only;
• Powered two wheelers using bus lanes where available consume an average of
between 100% and 500% less fuel than petrol cars using general traffic lanes only.'