Commuters will deal with a few closures and restrictions on Interstate 17 this weekend.

I-17 southbound narrows to two lanes near 7th Avenue for bridge work, from 9 p.m. Friday until Saturday at 11 p.m. This restriction is taking place for overhead sign work in that area of the freeway. Please drive with caution and be prepared to slow down and merge safely when approaching and traveling through the work zone.

7th Avenue is closed in both directions at I-17 for bridge work, 9 p.m. Friday to Saturday at 11 p.m. Please allow extra travel time and drive with caution around the construction area.

The I-17 southbound on-ramp at Bethany Home Road is closed for installation of the wrong-way vehicle detection system from 9 p.m. Friday to Saturday at 9 p.m.

The I-17 northbound frontage road will also be affected this weekend. Encanto Boulevard and Thomas Road are closed for the installation of the wrong-way detection system from 9 p.m. Friday until Saturday at 9 a.m. Please drive with caution and avoid the frontage roads during those times.

Finally, the Ironman Triathlon in Tempe will be affecting traffic throughout the weekend. Rio Salado Parkway is closed all weekend until noon Monday between Mill and Ash avenues.

Rio Salado will also be closed between Hardy Drive and the US Airways garage just north of 3rd Street from about 7 a.m. until noon Sunday. Eastbound traffic is shut down on 1st Street between Farmer Avenue and Rio Salado on Sunday. For more restrictions related to Ironman Triathlon, visit the City of Tempe's website.