A woman was arrested after drivers in Kentucky found her 4-year-old son walking alone along a highway apparently heading to Wal-Mart.

Barbara Vanderpool, 24, was arrested this week and charged with endangering the welfare of a minor, according to the Lexington Herald-Leader.

Vanderpool's son was found walking on a sidewalk along U.S. Route 25 in Williamsburg, Kentucky, at least a quarter of a mile from home. Investigators said Vanderpool had left the boy with his great-grandparents, who apparently were not able to care for him properly, according to the newspaper.

The boy told the driver who stopped and called 911 that "his mamaw said he could walk to Wal-Mart," according to Lexington's WKYT-TV. The boy's walk to that store would have been about 3 miles long.

The child has apparently been seen walking alone outside several times before. Police told the Herald-Leader that this was the "third time in recent months" that such an incident had happened involving Vanderpool's son.

About a week earlier, the child was allegedly rescued by officers after walking into the street.

Clint Davis covers entertainment and trending news topics for the Scripps National Desk. Follow him on Twitter @MrClintDavis.