One of the fundamental rules of safe driving is keeping both hands on the wheel. A Pennsylvania driver apparently opted to use her feet instead.

A video posted on social media on July 30 shows the woman holding her phone with both hands, with her sneaker-clad foot on the steering wheel.

"This woman drove with her feet and both hands on her phone while she was driving ...the entire time we were near her, which was a good 20 minutes.... Even on the highway I-76," Sarah DeLong wrote on Instagram.

WARNING: Video contains explicit language.

DeLong was traveling with her husband, Shawn DeLong, when they spotted the woman driving with her feet in a car with Pennsylvania license plates. The couple told 6ABC that the woman was traveling on the Schuylkill Expressway toward Center City Philadelphia.

"That I couldn't believe," Shawn DeLong told the news outlet.

Erin O'Neill may be reached at eoneill@njadvancemedia.com. Follow her on Twitter @LedgerErin. Find NJ.com on Facebook.