State and local police will be on the prowl for the next two weeks beginning tomorrow as part of a continuing statewide effort to curtail aggressive driving that was responsible for more than 900 traffic fatalities last year.

Fifteen Allegheny County police departments and state police from Troops A, B and D, which cover southwestern Pennsylvania, will be stationed at various locations across the region to participate in an enforcement program called Smooth Operator.

This is the fourth and last installment this year of the enforcement program. Previous efforts occurred at the beginning of March, July and August. The program operated last year on a limited basis last year in 12 eastern and central counties and was expanded statewide for the first time this year.

The enforcement effort targets particular areas and roads, based on information that links those areas to a high rate of aggressive driving-related crashes, said Alison Wenger, a spokeswoman for the Pennsylvania Department of Transportation in Harrisburg. Aggressive driving is the number one cause of traffic fatalities in Pennsylvania, she said.

PennDOT has allocated $2 million toward the Smooth Operator campaign, mainly to pay for police overtime. Though the program is designed to curb aggressive driving, police also will be on the lookout for impaired drivers, Ms. Wenger said.

Police will still operate drunken driving checkpoints at strategic locations throughout the Labor Day weekend, but those programs are separate from and in addition to the Smooth Operator program.

By far, most of the citations issued in the aggressive driving campaign are for speeding, though drivers who run red lights and stop signs are also high on the list. Some police have used a wireless infrared method of catching speeders, which uses probes positioned on each side of a road to track speed by calculating the time the probes detect the front and rear tires.

Allegheny County has averaged just over 1,600 total citations in the past three Smooth Operator enforcement endeavors this year.

During the last effort in the first week of August, 863 speeding citations were issued in Allegheny County, with a total of 407 citations issued for violations of traffic signals and signs. There were 97 citations issued for failure to wear seat belts, while seven drivers were arrested for drunken driving.

The Parkways East and West and state roads that include Routes 28 and 8 will be part of the target areas, Ms. Wenger said.