WEYMOUTH, MASS. (WHDH) - State police are investigating after a wrong-way driver caused multiple crashes on Route 3 southbound in Weymouth on Saturday before being taken into custody.

Troopers responding to numerous calls around 8 p.m. about a wrong-way driver in the northbound lane learned the driver was causing multiple accidents and driving erratically, according to state police. At some point, police say the driver got back on Route 3 in the correct direction before turning around and continuing to drive northbound on the southbound side of the highway.

After crashing into a guardrail, witnesses said the man was seen walking outside his vehicle with a knife.

He was arrested after throwing the knife toward the wood line.

He was taken to South Shore Hospital in Weymouth for psychiatric evaluation. His name has not been released..

No additional information was immediately available.

This is a developing news story; stay with 7NEWS on-air and online for the latest details.

(Copyright (c) 2026 Sunbeam Television. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)

Join our Newsletter for the latest news right to your inbox