The issue of service has to do with the fact that these violations are generated by automated equipment (speed cameras). Usually when you get a traffic ticket, the law enforcement officer signs it - you've been effectively served. But there is no officer involved in the camera tickets - a computer nabs you and records evidence, and supposedly a human who works for a "traffic enforcement" company under contact to the state, county (in my case) or municipality reviews it and signs it.

Anyway, the issue of service applies only to the camera tickets in Arizona, in my knowledge. It may apply elsewhere. I've only been looking at Arizona. And only at the camera tickets. There's been quite a controversy in Phoenix and Tucson areas about these technologies.