The Utah Department of Transportation is counting trucks in Provo Canyon.

About noon Wednesday, UDOT set up checkpoints for both eastbound and westbound truck traffic near the Murdock Canal in Provo Canyon.Flashing barricades direct trucks to pull into the checkpoints. Drivers are asked where their trip originated, their destination, what their load is and whether they are making stops in Utah or Wasatch counties.

Surveyors are also noting the number of pickup trucks traveling the canyon. The survey, which takes about 45 seconds to complete, will continue 24 hours a day for the next six days.

One motive for doing the survey is to provide the Utah Transportation Commission with information on truck traffic in Provo Canyon, said Kevin Beckstrom, UDOT spokesman. The survey should yield a "definitive answer about how many trucks are using the canyon," Beckstrom said.

Over the past several years, various citizens groups have proposed that interstate truck traffic be banned from the canyon for safety and air-quality reasons.

Most recently, a group of residents met with Gov. Norm Bangerter in February requesting that interstate trucks not stopping in Utah County be banned from traveling the canyon.

The residents said as many as 400 trucks travel the canyon daily. As the trucks exit the canyon, they must travel either 800 North in Orem or University Avenue in Provo. Because the streets are major access routes to 16 schools, truck traffic poses a threat to the safety of schoolchildren, the residents said.

Truck traffic also exacerbates carbon monoxide problems on University Avenue, according to the residents.

In response to the residents' concerns, Bangerter sent Attorney General Paul Van Dam a letter asking for an opinion on whether the Utah State Transportation Commission has the authority to restrict truck traffic in Provo Canyon.

Bangerter said in his Feb. 8 letter that he had directed the Utah State Transportation Commission to "find a way to keepinterstate traffic on the interstate system rather than using Highway 189 through Provo Canyon."

Bangerter's letter also asked Van Dam to ascertain whether it is "constitutional to restrict truck traffic on a federal highway on the basis of destination point" and whether it is legal to restrict truck traffic "during special circumstances such as when a highway is under construction."

On Wednesday, a representative of the attorney general's office said Van Dam has an opinion in "rough draft form" and that the opinion will be formally issued within the next week.