Local police officials say enforcing the state's ban on texting while driving is anything but easy.

"There are a lot of challenges for a patrol officer to tell if a driver is actually texting," said Chief Mark Bentzel of Northern York County Regional Police.

The law that took effect March 8 prohibits drivers from texting or reading texts, but did not ban their use of hand-held cellphones.

Drivers can still text when the vehicle they are driving is not in motion, such as when stopped at a red signal. Drivers can also look up phone numbers in their cellphones.

That has made it difficult for police officers to tell if drivers are texting or legally using their phones.

"It's a little difficult to enforce," said Sgt. Tony Beam of Springettsbury Township Police.

So far, Springettsbury officers haven't issued any citations for texting while driving, he said.

One issued: A Northern York County Regional Police officer pulled over one driver for suspected texting while driving, but that driver got off with a warning, Bentzel said.

The officer couldn't prove the driver was texting. The law doesn't not allow officers to seize cellphones, or other hands-free devices, to see if the driver is or isn't sending or reading a text.

Northeastern Regional Police have issued one citation for the infraction.

An officer was traveling behind a vehicle the officer thought was being operated by a possible intoxicated driver on Thursday, said Chief Bryan Rizzo.

It turned out the male driver wasn't drunk but rather his erratic driving was caused by cellphone use.

"The man admitted to checking his Facebook on this phone," Rizzo said.

Reading, sending, or writing all text-based messages, such as text and instant messages, emails or other written communications is prohibited by the law.

Texting while driving is a primary offense, meaning police officers can pull a driver over if they see the driver texting. The law carries a potential $50 fine.

Statewide: State police said its troopers have issued 31 citations for texting while driving violations.

A department spokeswoman said the total was drawn from an internal tracking system.

"The citations reflect a fraction of the number of warnings police have given out," said Maria Finn, state police spokeswoman.

The prohibition covers phones, computers or other devices that can send texts, emails or similar messages. It does not pertain to GPS devices, or systems that are physically or electronically integrated into vehicles.

However, there are exceptions to the law. Drivers in cars that have an integrated phone system, which is built into the car and includes voice control, will be able to text from behind the wheel while using such systems.

York Area Regional Police have also not issued any citations for the violation, said Officer Peter Montgomery.

Officers in marked patrol vehicles have seen fewer drivers looking at their cellphones, but Montgomery said he still sees people texting while driving when he's in his personnel vehicle.

"I also think people are hiding their phones lower in their laps to not make it visible to other motorists, which is worse," he said.

The Associated Press contributed to this report. - Reach Greg Gross at 505-5434, ggross@yorkdispatch.com, or follow him on Twitter at twitter.com/greggrss.