In Australia and Germany children of certain ages are allowed to ride on footpaths.
Under New Zealand law only people delivering mail or with cycle wheels less than 355mm in diameter can ride on a footpath. Not many bikes have wheels that small.
In reality people, including children, do ride on footpaths and do not get fined or ticketed.
The NZTA pointed out that cyclists have been marginalised during the last 50 years because there are more cars on the road and cycling is not as safe. In the 1980s 12 per cent of primary children biked to school. In 2014 only two per cent did.
Mr Rennie said any decision on footpath cycling should be based on common sense and safety. Sometimes it was safer to cycle on the footpath, and sometimes on the road.
Where there are good cycle lanes and trails, the road is safer.
The main danger on a footpath is cars backing out and unable to see a cyclist or pedestrian. It's especially bad in streets with high hedges or trees, such as Whanganui's Liverpool and Grey streets.
Mr Rennie said having an adult along while children learn safe cycling is a good idea. The adult can teach them to look out for backing cars, and to avoid elderly or vision impaired pedestrians.
He added that mobility scooters move as fast as bicycles and can be just as much of a hazard on footpaths.
"My kids have nearly been run over by mobility scooters as they step out of a shop in the main street."
Both cyclists and drivers needed to be watchful and courteous, he said.
"Cyclists aren't indestructible. Some take their lives into their own hands when they ride two and three abreast. It's not on in certain areas."