Police are hoping to identify the women to ensure her wellbeing and have launched an appeal for public assistance.
The young woman was spotted by a motorist around 9 pm on Saturday at the bus stop north of Holywood.
She is described as being 15-20 years old, petite, with long light coloured hair.
Police are hoping that other motorists in the area with dashcam footage may come forward, as well as a group of youths spotted near Newton Gardens Filling Station who may have information.
Inspector Lyndsey Nicolson, Police Scotland, said: "At the moment we don't know anything about this young woman but her state of undress caused concern for a motorist who brought it to our attention.
"We want to find out who she is and if she is OK, so would again appeal to anyone who saw her or who may have offered her any assistance to get in touch.
"I am particularly keen to hear from motorists, especially those with dash cam footage, travelling on the A76 between Newbridge and Holywood Station Straight between 8.30 pm and 9.30 pm on Saturday night.
"We'd also like to speak to a group of youths seen near to the Newton Gardens Filling Station around 7.30 pm as it's possible they may have information that could assist us identifying her."
Information can be passed to officers via 101. Please quote reference number 3982 of 6 November 2021 when calling.