PUC Certificate

A Pollution Under Control certificate records that a vehicle's exhaust emissions were tested and found within limits. Testing is done at authorised centres, and the certificate must be current and available whenever the vehicle is on the road.

Validity is short compared with other documents — commonly six months for most vehicles, with a longer initial period for new ones. That short cycle is what makes PUC the document fleets most often let slip: it comes round twice a year per vehicle, so a 300-truck fleet is managing roughly 600 renewals annually.

Because expiry is frequent and predictable, it is the clearest case in the whole compliance set for automation. Scheduling the test in advance of expiry, against the vehicle's planned trips, avoids both the penalty and the lost day of taking a truck off the road at short notice.