Yes you can use most signs. Most public road signs are in the public domain. There can be exceptions such as the Interstate shield, which is copyrighted by American Association of State Highway and Transportation Officials.
If you found this answer useful please press the appropriate quality of service button of 3 or greater. This is needed so I can get credit for my answer. If you have follow up questions please ask.
This communication does not establish an attorney-client relationship.Information provided here is not legal advice. Rather it is simply general information.
The sign I am specifically thinking of is the kind you see in Europe that shows you when you arrive in a village and when you leave a village, they have a red diagonal line thru it. with the "name" of the village.
The red diagonal line through just about anything is public these days. If someone designs a custom sign that has a red line that may be protected. If you just want to use the red line across a name you choose that is probably not going to be a problem.
Would I be able to trademark or service mark a road sign I put on a T shirt
No, they are in the public domain.
DISCLAIMER: Answers from Experts on JustAnswer are not substitutes for the advice of an attorney. JustAnswer is a public forum and questions and responses are not private or confidential or protected by the attorney-client privilege. The Expert above is not your attorney, and the response above is not legal advice. You should not read this response to propose specific action or address specific circumstances, but only to give you a sense of general principles of law that might affect the situation you describe. Application of these general principles to particular circumstances must be done by a lawyer who has spoken with you in confidence, learned all relevant information, and explored various options. Before acting on these general principles, you should hire a lawyer licensed to practice law in the jurisdiction to which your question pertains.
The responses above are from individual Experts, not JustAnswer. The site and services are provided “as is”. To view the verified credential of an Expert, click on the “Verified” symbol in the Expert’s profile. This site is not for emergency questions which should be directed immediately by telephone or in-person to qualified professionals. Please carefully read the Terms of Service (last updated February 8, 2012).