Sending a safety message about dangerous speeding on the steep, winding stretch of Interstate 17 in the Black Canyon City area north of Phoenix, the Arizona Department of Transportation has activated six new electronic signs to tell drivers they’re traveling over the speed limit.

These speed-feedback signs, featuring the posted speed limit and a digital screen, display vehicle speeds to I-17 drivers in areas between Black Canyon City and the Sunset Point Rest Area. The signs, which primarily track traffic in the left lane, display vehicle speeds starting 10 mph below the speed limit as well as “too fast” or “slow down” messages focused toward those who are driving above the limit.

ADOT installed the permanent speed feedback signs earlier this year as part of a $1.1 million I-17 safety project between New River and Camp Verde. They were activated in late November.

A study conducted in advance of the I-17 safety project found that Department of Public Safety troopers cited “speed too fast for conditions” as the leading driver violation in more than 40 percent of I-17 crashes that occurred in the Black Canyon City area between 2011 and 2015.

The new speed-feedback signs serve as a safety tool in an area where crashes and other incidents, including disabled vehicles, can cause closures and lengthy delays along I-17’s winding grade.

The three northbound I-17 speed-feedback signs are located near Table Mesa Road (milepost 236), Coldwater Road (milepost 245) and Bumble Bee Road (milepost 247). The southbound I-17 signs are located near Sunset Point Rest Area (milepost 251) and approaching curves on the downhill grade near Bumble Bee Road and Coldwater Road.

Other features of ADOT’s I-17 safety project north of Phoenix include four new digital message boards installed earlier this year to alert drivers to highway conditions and provide safety messages. Crews also have posted additional signs to advise drivers about highway curves.

Speed limits along I-17 generally range from 65 to 75 mph north of Phoenix, with lower advisory speeds on signs in some areas with curves.

ADOT also is studying possible improvements to the I-17 corridor between Anthem Way and State Route 69 at Cordes Junction before finalizing plans for adding new lanes and other safety enhancements.

With the help of funds from the Maricopa Association of Governments, which serves as the metropolitan planning organization for the Phoenix area, projects to add new I-17 lanes in areas between Anthem and Black Canyon City are now scheduled for construction in the years 2021-22.

The concept of building “Demand Lanes” between Black Canyon City and Sunset Point, for use as needed by the busiest direction of travel or in the event of a closure, is just one idea being considered for that mountainous section of I-17. Funding for improvements in that area hasn’t been identified.