It's claimed a reluctance to use public transport or share cars because of Covid-19 could be leading to a huge increase in traffic volumes.
The number of cars on the roads is almost back to pre-pandemic levels, with petrol use up significantly compared to the same period last year.
CSO figures show car traffic volumes are now at 90 per cent of 2019 levels in some regional locations.
Motoring expert Geraldine Herbert says there could be public health reasons for this.
"What we need to consider is that there is still a reluctance to use public transport.
"People who were maybe sharing cars going to work or giving people a lift are probably not doing that any more.
"I think we can't draw too much from this at the moment - it's still early days and we're still living in a fairly abnormal situation."
