A Pennsylvania congressman caught a cutting-edge ride to the airport on Wednesday.

Rep. Bill Shuster, a Republican from Altoona, made a 33-mile trip from Cranberry Township to Pittsburgh International Airport at about 11 a.m. in a computer-operated car.

The so-called driverless Cadillac SRX was designed by Carnegie Mellon University researchers who have been working on the project since 2008. The car uses inputs from radars, laser rangefinders, and infrared cameras to maneuver in traffic.

Shuster is the chairman of the House Transportation and Infrastructure Committee, and he was accompanied by Barry Schoch, secretary of the Pennsylvania Department of Transportation.

Shuster saw a Carnegie Mellon test vehicle about five years ago, and he said it was crammed so full of equipment that there wasn't even room for a person inside. Now, the 2011 Cadillac is basically a standard model with all the sensors and electronics discreetly hidden. It didn't look out of place on the drive to the airport, which began in a suburban area with stop-and-go traffic and then reached speeds of about 65 mph on a major highway. A Carnegie Mellon engineer was in the driver's seat as a safety precaution.

Shuster said he can now imagine a future where such vehicles enter the mainstream, potentially reducing accidents, fatalities and congestion on roads. But there's also a military angle.

"It's going to be great for our military to able to send vehicles into combat without people in them," Shuster said.

The U.S. Defense Advanced Research Projects Agency began holding competitions for driverless vehicles in 2004, and a Carnegie Mellon team won the 2007 race, along with a $2 million prize.

Raj Rajkumar, the leader of the Carnegie Mellon project, said the biggest design challenge for driverless vehicles is managing unpredictable events.

"It takes a long time to be taught all the things we know" about driving, Rajkumar said of the software. "You can build a system that works correctly today _ how do you know it's going to work well tomorrow? Because it's a new set of conditions, and you are unable to test all possible conditions. It's an infinite number."

Rajkumar thinks some driverless cars may reach the marketplace by 2020, though some experts say it will take longer. GM, Nissan and Google are all working on projects, as are other universities.

For now, engineers are still gathering data and running tests. A camera on the car recorded Shuster's trip and streaming video is available online.

Carnegie Mellon also let local law enforcement know about the road tests, and one officer imagined a possible future where DUI's no longer exist.

"It's very intriguing," Lt. Kevin Meyer of the Cranberry Township Police Department said as he waited for Shuster to depart. But Meyer added that law enforcement would have to adapt to such vehicles, too.

"We have to wait for the Pennsylvania laws to catch up with the technology that's involved in this vehicle," Meyer said, imagining a scenario where a driverless car is in an accident with one driven by a person.

"Who do we write up if there's a violation?" Meyer wondered.