Some of these dedicated units offer features such as external sound systems, illumination, LED panels and hot/cold boxes for product sampling, although they are illegal in many cities.
Box-type trucks with panels enclosing the cargo space can be turned into a mobile 3D display case.
Many companies use these trucks for parades, product launches, furniture displays, and general rapid-awareness creation.
[citation needed] In the US, mobile advertising falls under the First Amendment to the United States Constitution.
Since most complaints regarding mobile advertising relate to oversized trucks with loudspeakers, the bigger companies are more likely to have lawyers on retainer who can remind the authorities of US Constitutional protection of free speech and commerce.
However, content-neutral regulations of speech with a legitimate government interest are subject to a more deferential standard of review.
Ordinances banning mobile billboards on traffic and public safety grounds, regardless of message and without singling out commercial advertisement, have been largely upheld as legitimately and reasonably regulating the form, and not content, of speech.