Construction of a new camera-based pilot system to prevent wrong-way drivers is underway in Phoenix.
The Arizona Department of Transportation says preliminary work started in the past week along 15 miles of Interstate 17.
The state is installing the system because of multiple wrong-way wrecks.
The Transportation Board on July 28 awarded a $1.9 million contract to Mesa-based Contractors West Inc.
Traffic restrictions are scheduled Friday night and Saturday morning at I-17 and Indian School Road so workers can mount thermal cameras, install fiber-optic cable and rewire control cabinets.
The restrictions include closing Indian School Road at I-17 and closing both off-ramps at Indian School Road.
ADOT says future restrictions will be scheduled at other I-17 interchanges between I-10 northwest of downtown Phoenix and Loop 101 in north Phoenix.