Nitpick: The relationship between vehicle weight and road damage is a quartic (e.g. x to the power of 4), not an exponential

This is basically rule number one in the autocrat’s handbook: Rule something as illegal but make it necessary (e.g. give your public servants a near-zero salary, making them dependent on taking bribes to live). Then at any point the leaders have the legal grounds to arrest whoever they want for ‘corruption’. It’s a very common tactic.