No person shall willfully and unnecessarily hinder, obstruct, or delay, or willfully and unnecessarily attempt to delay, hinder, or obstruct any other person in lawfully driving or traveling along or upon any highway within this city, or offer for barter or sale merchandise on the highway so as to interfere with the effective movement of traffic.
(ILCS Ch. 625, Act 5, § 11-1416) Penalty, see § 71.999