Over 80,000 vehicles use Mercer Street daily. In planning its massive renovation plan, the Seattle Department of Transportation (SDOT) and its partners determined that nighttime and weekend work was necessary to keep the project on time while minimizing public impact. SDOT recently filed a Major Public Project Construction Variance (MPPCV) allowing them to work during those hours as well. Currently being planned:
Mercer Street lane closures on weekdays:
- No lane closures allowed from 6 – 9 am, and from 3 – 6 pm
- Single lane closures may be allowed from 5 – 6 am, 9 am – 3 pm, and 6- 7 pm
- Weekday multiple lane closures may be allowed from 7 pm to 5 am
Mercer Street lane closures on weekdays/holidays:
- No lane closures allowed from 2 – 6 pm.
- Single lane closures may be allowed from 6 pm – 2 pm the following day
- Multiple lane closures will be allowed from 7 pm – 1 am
Interstate 5 ramp entrance and exit ramp to and from Mercer St closures as follows:
- Sunday to Thursday from 11 pm – 5 am
- From Friday at 11 pm to Monday at 5 am
Timing will be adjusted due to special events like Bumbershoot, the Seafair Torchlight Parade, and victory celebrations for the Seattle Storm.
Nighttime noise- limiting measures:
- All trucks performing export haul shall have rubber bed liners.
- All backup warning devices shall be either broadband or a live backup observer.
- Hospital grade mufflers and silencers on all diesel powered equipment.
- Lighting and equipment such as generators, air compressors, etc. shall be directed away from oncoming traffic and buildings, and have mitigation shields if necessary.
- Radios will be used for all long-range communication.
- Any material or debris on the pavement shall be removed by hand or by sweeping. No scraping type of equipment or activity will be used to clean pavement surfaces.
- Moveable local noise barriers 10 – 12 feet in height, plus noise curtains will be put in place.
SDOT outreach staff will ensure the public is kept aware of any changes affecting nighttime noise levels, and that all inquiries and complaints are responded to. A Construction Hotline has been set up and will run 24/7 as a single point of contact, and that number is 206-419-5818. This SDOT link on the Mercer project carries a lot of information including timelines, maps and construction details.