Kenmore reports on traffic study after I-405 tolling begins

Both Kenmore and Lake Forest Park have been very concerned about the possibility of increased traffic from people trying to avoid the congestion caused by the new tolling on I-405. Kenmore recently released the following report.

On Sunday, September 27, 2015, the Washington State Department of Transportation (WSDOT) went live with tolling on the inside lanes of Interstate 405 between Bellevue and Lynnwood. Prior to this date, the City of Kenmore and WSDOT partnered to document the pre-toll levels of traffic volume and travel times through the City. Data was collected on Simonds Road, Juanita Drive, SR 522 at multiple locations, 80th Avenue NE, 73rd Avenue NE and 61st Avenue NE. Baseline data from WSDOT electronic travel-time detection hardware mounted along SR 522 between I-405 and I-5 was collected.

When tolling went live, WSDOT provided Kenmore with daily updates for two weeks. Weekly updates on live data gathering and analysis of traffic trends across the region will continue through November. The City continues to monitor our roadways. The City will collect new traffic data at the locations described above in January.

Traffic Volumes

After one month of tolling, the impact on Kenmore has been neutral. WSDOT maintains a live counting location near the intersection of 73rd Avenue NE and SR 522. The daily traffic volumes at this location have varied from being down 2% to up as much as 5%. These volumes are within the pre-tolling daily expected fluctuation. City data collected on Juanita Drive near the intersection with Arrowhead Drive for another analysis project has showed no increases in traffic volumes outside of expected daily fluctuations.

The City did experience abnormal congestion at Juanita Drive and Arrowhead Drive on the first week after tolling, but this was due to an issue with the computer that runs the intersection. The City has ordered a new computer and expects to have it installed in November.

Travel Times on SR 522

Travel times on SR 522 are similarly un-impacted. The WSDOT data does not focus specifically on Kenmore, but spans from I-405 to I-5. Travel times along the corridor are in line with pre-tolling baseline data. In the morning rush, travel times are down from the baseline data. The afternoon rush had an increase of 3-5 minutes in the first two weeks after tolling, but has returned to near the baseline travel time.

Transit Effects

WSDOT is reporting that regional transit agencies have noted double-digit increases in ridership since I-405 tolling went live and this has remained steady throughout October. The City has received comments about the early filling of park and ride lots in Kenmore since tolling went live. Monitoring of transit ridership will continue.

Regional Effects

Regionally, most other cities have experienced similar impacts. I-405 has experienced a significant decrease in the delay and travel times in the southbound morning rush, while the northbound evening rush, especially north of SR 522, remains a challenge.

The City of Kenmore continues to work with WSDOT to monitor incoming data, gather additional data where needed, and analyze trends that could be attributed to the I-405 express lane tolling project. Increased volumes in the City, especially on Simonds Road and Juanita Drive, as a result of the SR 520 tolling have not abated in three years. If you have any questions or concerns related to the City’s efforts to monitor the effects of the I-405 tolling, contact the City Traffic Engineer, Brett Schock 425-398-8900.