WFAA-TV

This wide-open stretch of Highway 121 has no speed limit signage.

DENTON COUNTY — This week, Natalie Clark drove her car for the first time on a new stretch of State Highway 121 betwen Old Denton Road in Carrollton and Hillcrest Road on the Plano-Frisco line.

Signs clearly indicate that this is a toll road — but what's the speed limit?

"I'm guessing 65," Clark said.

Lonnie Williams has been using the new highway since it opened on August 31. Certainly he knows what the speed limit is.

"I have no idea," he said. "No idea."

They're not being inattentive. There are no speed limit signs on the new Highway 121.

State law sets a default "prima facie" speed limit on new highways at 70 mph during the day and 65 mph at night.

"How many people know that law?" Clark asked. "I doubt very many."

But state troopers told News 8 the law gives them the authority to ticket motorists Like Lonnie Williams who exceed those limits.

"I'm going to fight it in court because it's not posted," Williams said. "Most people don't know what the state law says."

And that's the problem, according to Collin County Justice of the Peace John Payton, who says speeders caught on the signless stretch of Highway 121 may have a good argument.

"I think it creates an adverse situation between a peace officer who is trying to do his or her job and a citizen," Judge Payton said.

He added that he is also worried about people who drive too slow, creating a safety hazard on the highway.

North Texas Tollway Authority officials said they're conducting a speed study to determine how fast drivers should be allowed to go; it should be finished by the end of the year.

E-mail sstoler@wfaa.com