since they are waving tolls for songkran, can we ride on the highways as they are not toll roads???

No, just because they are free they are still restricted highways , dream on my friend, dream on

dont lissen to the naysayers.

give it a go.

those signs indicating 'fine and/or 90-days jail' are just for show.

agreed if you remove your plates and are confident you can outrun those beasty high way cop bikes have a go,

In all seriousness even if you could i wouldn't. Bad enough when people know to expect bikes, riding at speed with auto pilot drivers during holiday season would be asking for skin graphs and steel plates.