And it begins… Mercer West Stage starts April 2; May and beyond a traffic nightmare

We’ve had the heads up about the Mercer West Stage, and now the reality sets in – starting Tuesday evening, preparations will begin for the conversion of Mercer Street to two-way traffic from I-5 to Uptown. According to SDOT, impacts will be “small” in April, but we’ll all need to prepare for much larger impacts in May, when Mercer will be reduced to two eastbound lanes between 5th Ave N and Dexter, and SR 99 will be reduced to two lanes in each direction between Harrison and Valley.

Here’s the map of traffic flow for Mercer Stage 4:

Here’s the rundown of changes and closures in April:

• April 2: 9^th Ave N closed to northbound traffic from 8pm April 2 to 6am on April 3
• April 3: Westlake Ave N fully closed to traffic beginning the morning of April 3
• Late April: signal adjustments at 5th Ave N and Harrison St
• Late April: signalizing the intersections of Dexter Ave N and Republican St and Broad and Harrison St
• Late April: Broad St will be re-opened to two-way traffic when impacts to Mercer begin to help ease eastbound congestion heading towards I-5

Then comes May – it’ll make April seem like a piece of cake: first up in the larger construction stage is fixing the portion of Mercer that goes under Aurora. No definitive dates yet, but expect the following in May:

• Mercer reduced to two eastbound lanes between 5th Ave N and Dexter Ave N
• SR 99 reduced to two lanes in each direction between Harrison St and Valley St

The construction rendering below shows what the final portion will look like (in the distant future):

The Mercer West Phase widens Mercer to three lanes in each direction between Dexter Ave N and Fifth Ave N and converts the existing four eastbound lanes to two lanes in each direction between 5th Ave N and1st Ave N.

When completed in 2015, Mercer will have additional left-turn lanes, widened sidewalks, and a bicycle path between Dexter Ave N and Fifth Ave N. Roy St will also become a two-way street with bicycle lanes between 5th Ave N and Queen Anne Ave N.

April will be a bit messy, but think of it as the calm before the storm – May will be the beginning of the Mercer headache (nightmare?). What is messy now, will be much worse… until 2015.