NORTH ANDOVER, Mass. (AP) — State police say a woman walking along Interstate 495 in North Andover was struck and killed by a pickup truck that then left the area.

The woman was struck in the northbound lane at about 3:40 a.m. Monday.

Police have identified her as 48-year-old Robin Mendonca of North Andover.

A state police spokesman says investigators are looking for a later model black or dark-colored pickup with Massachusetts plates and running boards that will likely have front end damage. Anyone with information about the truck is asked to call police.

Exactly why the woman was walking on an interstate highway remains under investigation.