If you are stopped for speeding, the police must issue the citation and release you to go on your way, unless they have articulable suspicions that a crime is taking place. It would have to be something specific and particular, beyond a mere "hunch". In your case, unless something else was found or noticed by the police that indicated a crime was taking place, he/she had an obligation to let you go on your way after issuing the citation.
As far as city police on a state highway, the citation sounds like it was issued by a Worcester officer within Worcester city limits, which is within the city officer's jurisdiction.
If you think that you were improperly charged with something beyond speeding you should consult with an attorney. I cannot tell from your posted question as it seems to be cut off before you finished.
Answered on Aug 27th, 2012 at 12:05 PM