Travelers along Highway 305 on Bainbridge Island may have noticed spots of white paint marking large trees that line the highway.

According to the Washington State Department of Transportation, the markings have been left by crews working for WSDOT in recent weeks.

Crews have been gathering key topographical information in advance of the Highway 305 Safety Improvements project.

Workers have been identifying many features of the land, ranging from utility poles to trees. The survey crew is using the technique to mark off already catalogued features, said WSDOT’s Doug Adamson.

Washington state has allotted $36.8 million for investments in the Highway 305 corridor as part of the 2015 Connecting Washington transportation package approved by the Legislature. The improvements will stretch from the Bainbridge ferry terminal to Hostmark Street in Poulsbo.

Officials said the centerpiece of the proposed improvements include roundabouts at several major intersections along the corridor. The proposed locations are at Johnson Road, Totten Road, Milepost 7.9 (Masi Shop), Adas Will Lane, Port Madison Road, and Day Road.

Survey crews have also been working along the highway in recent months to gather important information as the state refines engineering designs for the 305 project. Crews have been locating underground utilities and gathering soil information; both standard operating procedure before any project, officials said.

WSDOT previously conducted a corridor environmental review. The next step is a project-level environmental review, officials said.

The current schedule shows construction beginning on Highway 305 roundabouts on Bainbridge Island in 2021.

WSDOT will host an open house on the 305 improvements on Wednesday, April 10 at Bainbridge Island City Hall to update residents on the project. The event is planned from 5:30 to 7:30 p.m. in the council chambers.