CO2 estimates

What does the CO2 estimates feature do in a nutshell?

When we calculate a route, we can estimate the CO2 emissions using published (often government) standards where available. These figures can only be used as a guide as CO2 emissions are abstract.

Why are CO2 estimates abstract?


  • Generate virtually the same CO2 emissions whether it’s empty or it carries 5 passengers.
  • Does that mean passengers travelling on a full bus use less CO2 than those on an almost-empty bus because it’s shared across more people? What happens when it’s empty?
  • Should passengers be penalised when the bus isn’t full or should full capacity be assumed to calculate?


  • This is only an average because CO2 emissions for cars vary significantly
  • Variances occur when driving a big or small car or an old or new one
  • The driver also impacts this – steady drivers, fast drivers and less confident ones
  • Levels of traffic, stopping and starting, using air con and numerous other factors play a part

Other factors

  • Electric Bikes
  • Different trains emit different levels of CO2 emissions
  • Type of ferry and other modes

Why use it?

  • To give searchers a rough guide of how their journey is impacting the environment
  • To set carbon emission reduction challenges
  • To increase your customer awareness of CO2 emissions and deliver a green product