all trucks should require a…

all trucks should require a diagnostic test to identify emission control systems are working as intended
It shouldn't be left to the test facility to suspect emission tampering.
Truckers will go from one test facility to the next till the are able to get a pass.

Integrating emission test with a safety inspection at the same location will require all shops doing safety inspections to purchase expensive emissions equipment.

In remote areas that will add an large extra cost as there would be no volume of testing per shop