Section 250-168-9 - DISPLAY1. The USDOT number issued to a motor carrier will be displayed on the registration certificate for all commercial motor vehicles operated by the motor carrier and subject to this rule.2. Intrastate, non-hazmat motor carriers are required to display the USDOT number on the commercial motor vehicle, The marking requirements can be found under 49 C.F.R. § 390.21.3. Intrastate hazmat motor carriers are required to display the USDOT number on the commercial motor vehicle as specified in 49 C.F.R. § 390.21.29- 250 C.M.R. ch. 168, § 9