The horse escaped from a racetrack in the Naples suburb of Agnano before it mingled with commuters and workers on one of the most trafficked orbital roads in the car-crazy Italian city.
A video of the horse can be seen here.
The animal raced along for about five hours and went the wrong way on the Vomero-Fuorigrotta stretch before being stopped by a safety car and steered towards the nearest exit.
ANSA