The current standards concerning non-English signs are as follows: Sign Standards Manual, Page 2-2, Paragraph 4 Non-English Signs:
In areas where a significant percentage of the population speaks primarily in a foreign language, the use of symbol signs (see Section 8) is strongly encouraged. When no symbols exist or where words are essential, two signs - one in English and one in the foreign language - should be placed side by side.
The manual provides an example of how to show both English and a foreign language. If the project feels they have a need for non-English signs, follow this example. There will be no "nationwide" translations recommended because dialect and idioms uvary across the country. We strongly encourage projects get local help in translating any wording of signs, brochures, etc. If there is no "non-English" language expert at the field site or in your district office, find a local expert fluent in the language as spoken in your area. The use of symbol signs is highly recommended wherever possible.
If you are located close to other projects, whether in the same district or not, you should communicate with each other on how to resolve this issue locally.
Title 36 sign. There will be no straight foreign language translations of Title 36 because of HQ Office of Counsel's concerns over the accuracy of the translation(s). There are also cost considerations about printing and choice of language. However, OC does say that a foreign-language synopsis of the regulations is okay. Before deciding to utilize non-ENglish signs park managers should identify the need for such signs by determining the percentage of visitors that need Non-English signs and that those signs are needed for safety and public relations.