The driver of a silver Audi going south on Interstate 79 passed one of those portable signs that measure and display a vehicle's speed. A short distance later, he passed another one. Neither sign persuaded him to slow down. The next gadget to record the Audi's speed was a radar gun held by a Pennsylvania state trooper.
It displayed 75 mph, and seconds later the Audi was on the berm, stopped just ahead of the strobing red and blue lights of a police cruiser.
The scene was repeated again and again on Wednesday as state police began a two-week crackdown on speeding and aggressive driving on I-79 near Southpointe, catching drivers going as fast as 80 mph in a 55-mph zone.
There was a twist: Two speed trailers -- the portable signs that display how fast a vehicle is going -- were placed on both approaches to the enforcement area. Drivers had two chances to ease off the throttle before reaching the police cars.
"Our cars drive so quiet and so smooth. It's easy to hit 70 mph and not even know it," said Jay Ofsanik, safety press officer for PennDOT District 12, which includes Washington County.
"We're using a multifaceted approach to educate drivers -- 'Hey, this is really how fast you're going.' After drivers have had opportunities on two separate occasions to see how fast they are traveling, they make a conscious decision to slow down or keep going," Trooper Joseph Christy said.
Police from the Washington and Pittsburgh barracks took positions in the median and used radar to clock the traffic. They rarely had to wait more than a few minutes to nab someone, even though they were only chasing down "the worst of the worst," as Trooper Christy put it.
The enforcement campaign, which runs through Nov. 13, will include 320 municipal departments across Pennsylvania and is paid for with $2.5 million in federal funding.
It is the third wave of such enforcement in Pennsylvania this year, Mr. Ofsanik said.
The local effort won't be limited to I-79, although that locale was chosen for the kickoff event because police identified it as a hot spot for aggressive driving and crashes. Police were out at 6 a.m. and continued the enforcement blitz off-and-on throughout the day.
The Pennsylvania Department of Transportation reported 5,755 crashes statewide last year related to aggressive driving, up from 4,763 the year before. Fatalities from those crashes rose from 130 to 168 in that period.
Steve Cowan, PennDOT safety press officer for District 11, said there were 79 speed-related accidents just on the Allegheny County portion of I-79 last year. Mr. Ofsanik said the stretch in Washington County between the north junction with I-70 and the Allegheny County line had 254 crashes caused by speeding and three fatalities from 2006-10.
If the apprehended drivers didn't know it before the troopers typed out their speeding tickets on their on-board computers, they do now -- a leaden foot can make for a lighter wallet.
The fine for going 70 mph in a 55 mph zone is $55, but that's just the start of it. By the time various fees and court costs are assessed, the bill comes to $140.50. The driver who was clocked doing 80 mph will owe $170.50 if the ticket sticks.