Black Diamond’s SR 169, Roberts Drive intersection to close for 30 days

The highway will still allow north-south traffic, but expect extra congestion for the next month.

Black Diamond commuters be warned: The intersection at Roberts Drive and State Route 169 will close for road work at the end of March, and though highway through-traffic will not be blocked, drivers should prepare for congestion and consider alternate routes.

The intersection itself will remain closed 24 hours per day to both vehicles and pedestrians during the construction starting March 31. Construction could last up to 30 days, according to the city of Black Diamond.

SR 169 traffic will be free to move north and south but drivers won’t be able to turn west onto Roberts Drive. Residents on Roberts Drive will have to use Morgan Street or Auburn-Black Diamond Road to get home.

The city cautions that traffic in the area will likely be more congested during the construction.

It’s one of many transportation projects in the area planned over the next several years as the massive Ten Trails housing development paces closer to conclusion.

For this project, the city will demolish the existing Roberts Drive turnoff from SR 169 and pave a new access road with improved visibility. Construction will take place on Roberts Drive from Morgan Street to SR 169.

The improvements to the road are temporary and intended to keep the intersection safe and traversable while Oakpointe, the developer of the Ten Trails neighborhood, and Black Diamond work on plans for a future roundabout in the area.

“Oakpointe and city staff felt like something needed to be done to improve the safety of the intersection while we continue to work through the future roundabout design,” a spokesperson for Oakpointe said. “Realigning Roberts Drive is a relatively straightforward construction project that both significantly improves visibility for the Roberts Drive/SR169 intersection and increases the distance between the Roberts Drive intersection and the Ravensdale Road intersection, which allows drivers more time to react to other cars’ movements.”

The total construction cost of the intersection realignment is about $400,000, and the bill is 100 percent covered by Oakpointe.

As for the future roundabout, “We anticipate starting construction of the roundabout in late 2022,” the spokesperson said. “We expect that the Roberts Drive/SR169 portion alone will cost approximately $5 million dollars to construct, and Oakpointe will be paying for the work.”

More information about the intersection realignment is on the city website at www.ci.blackdiamond.wa.us.

Black Diamond also gave the following guidance for drivers in the area:

Drivers heading east on Auburn/Black Diamond Road: Heading east into Black Diamond on Auburn/Black Diamond Road, all trucks must turn left onto Lake Sawyer Road. All other vehicles are encouraged to take the Lake Sawyer detour as well. Drivers will head north on Lake Sawyer Road and, after the Lake Sawyer Grocery, turn right onto 288th St. This will take you to State Route 169.

Drivers heading west on Roberts Drive: Drivers intending to come off State Route 169 and onto Roberts Drive must find alternate routes if they are trying to head west to Auburn/Black Diamond Road. Drivers can follow the detour along SR 169, which takes them to 288th Street, or can take Jones Road onto Morgan Street. Trucks can only take 288th Street.