Smoke pollution a concern

I write with disgust about smoke pollution in Lae.
Every time as I drive to work or, while drop off my kids at school etc, I see a lot of vehicles, especially PMV buses, with extensive amount of diesel smoke coming out of their exhaust pipes.
This concerns me as it poses health risks and hazards for road users and the general public as a whole. Why is the Morobe transport board or relevant transport authorities not doing something about this?? I suggest they start charging these PMV buses some kind of fee.
This is so owners know the importance of servicing their buses before getting them on the public road.
The government will also make some money out this.
Thanks and over to  Morobe road transport authorities.

Chillie Peps
Lae, Morobe