Olivia Thigpen of Lyneham Drive, Quedgeley, indicated a guilty plea at Cheltenham Magistrates’ court.
The charge relates to an incident on the A38 Quedgeley Bypass which caused the road to close for around an hour.
Thigpen admitted that she was guilty of doing an act which ’caused closure of the A38, which caused police resources to be used to close main roads in Gloucester to allow emergency services to deal with you and allow air ambulance to land, causing massive disruption to traffic on busiest roads in area and that created a risk or caused serious harm to the public or a section of the public.’
The magistrates remanded her in custody till May 24 for a pre-sentence report to be prepared.
Thigpen had also faced two other charges which were withdrawn by the prosecution at court.
One was of placing herself in a precarious position on a flyover above a grass verge on May 2 with intent to harm herself and causing members of the public to be alarmed, distressed, or to intervene.
The incident allegedly brought traffic to a standstill and involved extensive deployment of police officers and PCSOs.
The other discontinued allegation was of breaching bail by going onto a road bridge or flyover on May 3.