Big Mercer Mess Traffic Change Starts Today

SEATTLE, WA - One of the worst parts of using Seattle's always awful Mercer Street might get better starting Tuesday. WSDOT turned on ramp metering for the I-5 entrances at the east end of Mercer Street Tuesday, a move meant to sort out the mess merging drivers.

WSDOT has been testing the meters on weekends since March 10. But Tuesday is the first time the meters will be on during the afternoon weekday rush hour. Meters are used at on-ramps throughout the region. In general, the meters make drivers wait a few seconds at a red light before entering the highway.

WSDOT says metering has a number of benefits - reducing traffic on I-5, preventing traffic accidents. But one major benefit is that meters help reduce the stress of merging, which can cause drivers to jockey for position rather than merge politely.

"Many of us can feel a bit stressed looking ahead to merging traffic. Whether merging lanes or merging from the on-ramp to the freeway, predicting fellow driver behavior can be taxing. The new signals will help to ease some of the anxiety by alternating traffic and taking out the guesswork," WSDOT wrote in a blog post.

Mercer has long been a conduit for drivers headed from downtown and SR-99 to I-5, carrying about 80,000 cars per day. Beginning in 2010, the Seattle Department of Transportation began a major overhaul of the road. The overhaul, plus new timed signals, have reduced the average wait along Mercer from 34 minutes to 17 minutes, according to SDOT.

Image courtesy SDOT