Mountlake Terrace traffic report: volumes rebounded after 2020; several intersections identified as collision hot spots

City Traffic Engineer John Merrick presented the city’s 2024 annual traffic report to the Mountlake Terrace City Council, outlining traffic volumes, speeds and collision patterns and identifying specific corridors and intersections for follow-up work.

Merrick said the city’s analysis used traditional pneumatic tube counts, contracted field turning-movement studies and a new subscription service that aggregates anonymized smartphone and connected-vehicle data, allowing staff to look back to 2017 for street-level trends. He told council the data helped staff focus limited resources on corridors with the highest collision rates and potential for mitigation.

Merrick and Public Works Director Gary Schmick described three headline findings: traffic volumes fell sharply in 2020 and have been trending back up since; the portion of drivers traveling faster than most others rose during the low-volume pandemic period and has declined as volumes returned; and collisions remain concentrated on a few corridors. “We saw a pretty sharp reduction in volumes in 2020,” Merrick said, and added the new data source “lets us get traffic speed and volumes for any street in the city, going back to 2017.”

Key statistics Merrick cited from the report: 200 total recorded collisions in the city in the most recent 12‑month period; 60…