The annual total for the post-primary school run in Northern Ireland is a staggering 130 million miles more than it needs to be - because many children don't attend the closest school, a new study has found.
That figure represents 40m more 'wasted' miles than the distance from the Earth to the Sun and is the equivalent of an extra 10,000 cars on the road.
The figures are revealed in one of a new series of reports by Ulster University's Unesco Education Centre, which looks at ways of transforming education in Northern Ireland.
The study looked at how far each pupil lives from their school and compared the distance to what they would be travelling were they to attend the nearest one.
Much of the reason for the extra mileage, which the study said has not only financial but environmental implications, lies in the divided nature of the education system here, with most families still selecting schools based on personal choice and, often, religious denomination.
The academics argue that a single education system, where pupils attended the post-primary school nearest their home, would have enormous benefits for the environment. It would also save millions of pounds for both families and the Department of Education, which has estimated the cost of providing free school transport at around £81m each school year.
Dr Stephen Roulston, from Ulster University's School of Education, said the number of extra miles are "remarkable".
"We wondered what it would look like if pupils instead attended their nearest post primary school," he said. "Most schools would have pupils coming from primary schools of both traditions. They would become naturally mixed, but the amount of travel would be much reduced.
"This would result in other benefits like reduced congestion.
"In fact we were able to calculate just how many additional miles were travelled by all pupils in a selective, duplicated system with open enrolment. It's a remarkable 130m miles every year."
The research also showed that the number of parents taking their children to school by car has risen significantly over the past few years.
In 2013/14 they found that 59% of pupils travelled to primary school by car. This rose to 68% in 2019/20.
The figure also increased in the post-primary sector, with 33% travelling by car in 2019/20 as opposed to 30% in 2013/14.
"There is a cost there for parents, for the community and for business through unnecessary congestion, and of course for the environment," said Dr Roulston.
"The additional travel is the equivalent of 10,000 extra cars on the road."
When looking at the additional mileage travelled with pupils not attending their nearest post-primary school, the research found that it amounted to an average of 4.85 miles per pupil each day.
That works out at 897.25 miles per pupil each school year and across the whole of the post-primary education system is 130,177,516 miles per year.
"Of course, a move to local cross-community comprehensive post-primary schools is not a panacea," Dr Roulston added. "Some degree of choice would still be required and increasing social mixing might be difficult to achieve in post-primary schools in culturally homogenous areas.
"But any move towards a fairer and more cohesive society would have considerable benefits."