The northbound lanes of State Route 110 from Hill Street to the 5 Freeway will be closed overnight, each night from Tuesday night through Thursday, Caltrans announced.
From June 29 to July 1, from 11:59 p.m. to 6 a.m. on Tuesday, Wednesday and Thursday, the northbound lanes will be closed so road crews can paint the exteriors of Arroyo Seco Parkway tunnels.
The tunnels are part of a historic route in Southern California, and the tunnels will be painted with anti-graffiti coats to closely match the previous color.
Detour signs will be posted, Caltrans said.
The $6 million safety enhancement project on State Route 110 stretches "from the College Street overcrossing to the Grand Avenue overcrossing."
In addition to painting the tunnels, Caltrans will add "upgraded metal beam guardrails, crash cushions, concrete barrier walls, safety lighting and access gates," remove a raised island and provide safe maintenance vehicle pullouts over the course of the next year. The project is set for completion in fall of 2022.
The Tuesday, Wednesday and Thursday lane closures will reopen each morning.
The work schedule is subject to change due to weather or construction-related issues, and closures may start and end later than the posted times, Caltrans said.