"We found the time you could shift people and get them to think about other modes of transport was when they move jobs or schools, or they shift houses.
"It's that first little window because once they've made their decision about how to get to work, they don't revisit it because it's easy."
The second part of their study would look at decision making and 'satisficing', a term used to describe how people often make decisions that are easy and good enough, rather than the absolute best outcome for themselves and society.
He said the initial study found car drivers' level of commitment to using their car was much higher than people who cycle or who use public transport, the survey revealing why it is often difficult to get people to use these more sustainable commuting modes.
And while the study had also shown there was a desire by all commuters to be more sustainable and choose more sustainable travel, a large portion of the population believed they didn't have the option for more sustainable travel choices, or it wasn't safe enough.
"We learnt although people have a desire to be more sustainable, they feel it's too dangerous to ride their bike and for public transport the perception is there's not quite enough buses and they don't quite go where they need them to go."
Professor Charlton said it suggested more work was needed to change or improve those issues for commuters or to help people understand what choices they do have for more sustainable travel options.
He said there was an opportunity to work closer with employers around commuter travel choices particularly when they recruited new staff because getting to work was now part of workplace safety.
"There is an opportunity to work with employers. New Health and Safety legislation means employers have a duty of care to make sure their employees get to work safely and not just safely but I think also economically and sustainably."