The deadline for the registered owners of all such vehicles, which includes passenger vans and charter buses, to have the checks completed is Aug 31, the notice warned.
The safety drive aims to reduce the number and severity of accidents from unroadworthy vehicles, PLTO Chief Banyat Kantha explained in the notice.
Unsafe vehicles have resulted in accidents that have caused deaths, and low-cost tour groups use unsafe buses to transport tourists, Chief Banyat said.
Checks can be conducted at the PLTO on Saturday, Aug 25, from 8:30am to 4pm.
Operators can call the PLTO at 076-214929 ext 104 to arrange to have their vehicles inspected on the Aug 25.
Alternatively, inspections many be carried out at the Chotima Driving School centre, located at 77/3 Moo 3 on Phra Phuket Kaew Rd in Kathu, the notice said.
The centre is open daily from 8:30am to 5pm and can be contacted by calling 076-612661, the notice added.