Seneca Street Traffic Analysis

The Seneca Street extension has been discussed for many years and has been included in several planning documents.  The Seneca Street extension was most recently included in the City's Transportation System Plan (TSP) adopted in 2013 to improve circulation and safety and to provide better access to the adjacent properties.  You can view the excerpt from the TSP where project R40 is shown.  Project R40 is defined as a short-term project to create a local street grid system on Urban Renewal Block 2 upon redevelopment with a connection opposite SW Seneca Street.

The street extension and relocation of the Council Building is also mentioned in the City's Central Urban Renewal District (CURD) Plan. 

Below are excerpts from the Findings and Conclusions for the Nyberg Rivers Project related to Seneca Street:

Based on a review of all of the traffic evidence in the record, the City finds that the best operation and functional transportation environment is achieved with a signalized extension of Seneca Street and closure of the driveways south of City Hall and south of the Council Building. 

-Page 11, Findings and Conclusions

City Council finds the following transportation improvements are needed for the Master Plan to comply with Goal 5, and therefore imposes them as conditions of approval:

The Seneca Street extension to the Nyberg Rivers site with a signal at SW Martinazzi Avenue constructed to the standards of a Minor Collector Street.  The time of construction will be determined through the public facilities decision process and is not anticipated or required to occur prior to removal of the Council Chambers building.

-Page 14, Findings and Conclusions

Read the full report of findings and conclusions for the Nyberg Rivers Master Plan.

Seneca Street Traffic Analysis:

The traffic analysis that was completed for Nyberg Rivers project shows that the extension of Seneca Street would improve traffic flow and safety in the downtown area.  Below are excerpts from the traffic studies.

The Kittelson & Associates, Inc. Addendum to the Traffic Impact Analysis from June 21, 2013 states:

• The City driveway currently meets the City of Tualatin's Level of Service standard and will continue to meet the standard with the added traffic from Nyberg Rivers.
• There are some existing operational deficiencies that exist at the City driveway under existing conditions due to the presence of standing queues on SW Martinazzi that occasionally extend to beyond the City Hall driveway. The analysis presented to date has demonstrated that the Nyberg Rivers development will have very little impact on this existing condition.
• An option that would eliminate the City driveway and replace it with the extension of SW Seneca Street has also been studied.  Under this new SW Seneca/SW Martinazzi intersection would be signalized and would result in significant operational improvement relative to the existing condition at the aforementioned City driveway.

None of the above conclusions suggest that the City hall driveway "must" be closed as a result of the Nyberg Rivers development as this conclusion is not supported by the traffic engineering evidence.  Representatives from CenterCal remain very willing to work with the City to implement solutions that improve the operations at the driveway (including helping to implement the Seneca Street extension.)

Read the full addendum report from Kittelson & Associates, Inc. dated June 21, 2013.

While the street extension has been discussed and planned for over the years, the City Council must decide whether to construct the street now in conjunction with Nyberg Rivers, or wait to construct the street at a later time.  

Return to the Project Home Page.