In Virginia, trailer plates aren't distinguished between travel trail and just trailer. If you have a trailer whether for carrying cargo, horses, or travel trailer, they are the same.
The only difference in trailer plates is either regular ones, or permanent ones. Regular ones are renewed every 1 or 2 years. Permanent ones are permanent. The cost of a permanent plate is roughly 3 times the 1 year rate. So, any year beyond the 3rd year is free.
Permanent trailer plates are $100. if you keep the trailer for 15 years, that's all you ever pay.
By the way, even permanent trailer plates can be personalized in Virginia. In Virginia a person has a huge range of choices of plates, all of which can be personalized ( for an extra fee of course). There are 98 different specialized plates, plus 44 different military related plates, plus 92 different college plates, plus twenty or thirty plates that fall in the Other category. The Other category includes the generic VA plate, plus ones with a Cardinal on them or mountians, and the trailer plates, etc.