AIKEN --- For the past month, bright-yellow chalk marks have been appearing on tires in downtown areas -- evidence of Aiken Public Safety's enforcement of the city's new two-hour parking limit.

Cpl. Sonny Ford has been one of the enforcers, and he said the effect has been to open up more parking.

"We do see a difference in parking downtown and the spaces available, especially during lunchtime," he said.

Cpl. Ford is one of two mounted patrol officers who have gotten off their steeds to mark tires with chunks of yellow chalk until the department decides who will monitor the downtown parking long term.

"You might not see them riding a horse as much, but you'll see them out there chalking the tires," said Lt. David Turno, of the special services division.

The city council passed the two-hour parking limit in downtown last fall to alleviate a lack of parking caused by people leaving cars parked all day.

A parking study conducted in August 2006 found that 111 on-street parking spaces within the two blocks along Laurens Street and Richland Avenue were occupied by one vehicle for six hours or longer.

The study also found that the long-term occupants tended to be people who work downtown.

The new regulation went into effect the first of the year, but enforcement didn't begin until March 1.

Cpl. Ford said the department has issued warnings -- more than 100 -- in the past four weeks in an effort to educate the public.

"We try to contact the person who owns the vehicle," he said. "They might not be aware they are parking in a designated two-hour parking zone."

The two-hour parking limit applies only between 9 a.m. and 4 p.m. Monday through Friday.