MADISON, Wis. -

Madison police said they’re again using an unmarked squad car, known as the Shadow, to enforce traffic laws on the Beltline.

The police officer driving in civilian clothes was on the West Beltline Tuesday morning and was looking for unsafe driving behaviors. The officer radios other officers to make traffic stops.

Thirteen citations and five warning were issued over two and a half hours Tuesday. Police said one driver caught going 80 mph said he was speeding because all the traffic was making him mad.

Police expect to use the Shadow over the coming months, especially on the West Beltline.