The Arizona Department of Transportation has added large “Wrong Way” signs along Interstate 17 on bridges and other structures to help prevent wrong-way drivers.

The signs are being placed along a 15-mile stretch of highway between the Interstate 10 interchange and Loop 101. Early next year, ADOT plans to install a wrong-way detection and warning system that uses thermal cameras to detect and warn motorists about wrong way drivers.

The signs each measure 8 feet by 5 feet, and are part of an effort by ADOT to test countermeasures against wrong-way drivers on Interstate 17.

Twenty-six of the signs, 13 in each direction, have been installed to face the wrong direction of travel along I-17. They are mounted above the left lanes of the freeway because research has shown that wrong-way drivers, most of whom are impaired, likely will be traveling in those lanes.

Measures already in use to get the attention of wrong-way drivers include larger, lowered “Wrong Way” signs at many freeway off-ramps in the Phoenix area as well as interchanges on other state highways.

Crews also have added large white arrows with red reflectors on the travel lanes of dozens of exit ramps to point out the correct direction of travel.

ADOT’s pilot I-17 wrong-way vehicle alert system in Phoenix is scheduled to be fully operational early next year. Thermal cameras will detect wrong-way vehicles on I-17 off-ramps, alerting ADOT and the Arizona Department of Public Safety, posting warning messages to drivers traveling in the right direction along the freeway and activating an internally illuminated, flashing “Wrong Way” sign on the ramp as a way to get the driver’s attention.