The Black Diamond City Council recently updated its list of future road and transportation improvements.
The 2020-2025 Transportation Improvement Plan, also known as the TIP, was passed unanimously by the council during its regular June 20 meeting.
The TIP is more of a wish list than a legally binding document, but the state requires cities to update their transportation plans every July in order for those municipalities to be eligible for related grants.
A couple of the roughly 30 proposed projects come with a 7- or 8-figures price tag, the most expensive by far being a new two-lane roundabout at the Roberts Drive/State Route 169/Black Diamond-Ravensdale intersection.
According to the Washington State Department of Transportation’s 2016 Annual Traffic Report, somewhere between 11,000 and 14,000 vehicles per day drive on State Route 169 between Lawson Street, within city limits, and SE 280th Street, north of Black Diamond and just inside the Maple Valley city limits.
This number is only expected to increase as Ten Trails, the housing development being built by Oakpointe, continues to grow.
The estimated cost of this project, which is expected to be tackled in 2020, is about $12 million. Much of the project cost is expected to be covered by Oakpoite, but the developer’s agreement with the city stipulates the city should seek grants to offset the cost.
“We’re in the process of designing that improvement, so the state and the city both have review of that,” said Colin Lund, Oakpointe’s director of development.
The next two most expensive projects are expected to by fully covered by Oakpointe.
An estimated $2.9 million project, titled the Ten Trails Parkway, would extend a “minor arterial” — roughly 0.7 miles — inside the Ten Trails development. According to the TIP, this project would be tackled in 2021.
Then there is the Lawson Connector/Lawson Parkway project, which will be a new 36-foot wide road that connects Oakpointe’s smaller development project, Lawson Hills, to a new State Route 169 intersection that will start just south of the current State Route 169/Roberts Drive intersection, curve around McKay Lane, connect to Lawson Street and continue southeast until it reaches the development.
The estimated $3.2 million project would include bike lanes, pedestrian facilities, and street lighting. This project is slated to begin in 2023.
Other projects not covered by Oakpointe include a downtown public parking space in the Baker Street and Railroad Avenue area, estimated to cost about $145,000; a $75,000 project to seal and paint the underside of the Rock Creek Bridge; a $1.75 million project widening Roberts Drive from the Black Diamond library to State Route 169, as well as adding sidewalks, street lighting, and stormwater improvements; adding a 6-foot wide sidewalk from Roberts Drive to James Street for $55,000; starting a downtown pedestrian and bicycle link study from James Street to Jones Lake Road for about $30,000; and a $700,000 sidewalk installation between Baker Street and Railroad Avenue; and multiple general street improvement projects, which include chip sealing, patch work, and overlay.