Catching people who are texting while driving might be harder than actually texting while driving.

At least that's the message that emerged from a dragnet Thursday along a busy stretch of Interstate 394 west of downtown Minneapolis.

"It's hard to see, hard to watch for," State Trooper Scott Fredell said as he drove the freeway looking for signs of distracted drivers. "It's a good law, just hard to enforce."

Minutes later, Fredell joined two other troopers pulling over drivers at an exit. One of them acted as a spotter, standing behind a light pole and picking out drivers who appeared to be looking at cellphones or not wearing seat belts.

The two-hour exercise netted two inattentive drivers out of the 50 who were stopped. One got a warning for text messaging.

Texting drivers have come under greater scrutiny amid rising concerns over inattentive driving and accidents. The stakes can be serious, as in the case of an Eden Prairie driver charged this week with felonies in connection with a collision that occurred while she allegedly was texting.

Nearly 1,600 drivers have been cited in Minnesota for texting since the state passed a law making it a petty misdemeanor in 2008, said State Patrol spokesman Lt. Eric Roeske.

Not everyone is supportive of highway sweeps like the one along I-394 where drivers are pulled over in large numbers. A bill pending in the Minnesota House would prohibit officers from conducting "saturation patrols and sting operations" to look for drivers not wearing seat belts -- often a justification for also looking for evidence of text messaging.

When Trooper J.E. Brings -- the spotter -- saw a man holding a cellphone in his hand while exiting the freeway, he signaled to the other troopers to pull him over. The driver agreed to let Trooper Todd Merwin look at his phone, and Merwin spent a couple of minutes looking for text messages.

Although Merwin found one sent to the driver about 15 minutes earlier, he let him go.

"I'm not going to tag somebody unless I'm sure that they're actually texting," he said, adding that police need to ask permission to check a cellphone during ordinary traffic stops.

The driver, Brandon Voronyak, 33, of Minneapolis, wasn't put off by the exercise. "I don't text and drive," he said. "I've seen a lot of distracted drivers texting."

But seeing enough evidence to stop a driver not violating another law isn't easy.

"It's very tough to catch them and get them to admit to texting," said Fredell.

Pat Doyle • 612-673-4504