The most important word in that entire Wikipedia article is brief. The stop requires probably cause and must not exceed the minimum time necessary to inform dispatch, issue a citation, and perform a basic warrant search on their computer. Signing a citation provides a written promise to appear in court so that police do not have to arrest you and is not an admission of guilt. Refusal to sign is grounds for arrest. Either way police cannot reasonably communicate to you from another moving vehicle, which is the primary basis of such a stop, not a detainment pending other inquiries.