Preliminary Alternative Alignments
During the Project Advisory Committee’s February 5, 2004, meeting, the members came up with nine different alternatives and configurations for making the connection through the 170th / 173rd corridor. In addition to the 74' right-of-way that is shown on the alternatives below, the Project Management Team will also be looking at using a 60' right-of-way. The 60' right-of-way can still accommodate the three-lane road section with bike lanes and sidewalks but would not include a separate planter strip.
Between the February meeting and the March 4, 2004, meeting, the engineers at David Evans and Associates, Inc., developed the PAC proposals using adopted engineering standards.
During the March 4, 2004, meeting, the PAC dismissed Alternatives 2A, 3, 4, 4A, 5 and 6 and agreed to further analyze Alternative 1(with option 1A) and Alternative 2.
Alternatives that the PAC recommended for Further Analysis
Alternative 1 – Predominantly uses 170th Ave. and transitions the road between 170th & 173rd Ave. near the north end of the project corridor.
Alternative 1A – Same as Alternative #1 but includes frontage improvements to the Elmonica School for bus access.
Alternative 2 – Predominantly uses 173rd Ave. by transitioning the road between 170th & 173rd near the south end of the project corridor.
Alternatives that the PAC rejected
Alternative 2A – Similar configuration as Alternative 2 but uses sharper curves through the transition.
- This alternative does not meet the minimum design standards for the curvature of the roadway
Alternative 3 – Predominantly uses 173rd Ave by creating a T-intersection between the MAX line and Merlo Rd and transitions traffic south of the MAX line.
- This alternative creates a new MAX crossing,
- This alternative creates operational problems for cross-traffic because of the new crossing.
Alternative 4 – Predominantly uses 173rd Ave. and transitions the road between 170th & 173rd between the MAX line and Baseline Rd.
- This alternative requires substantial acquisition of property with transit oriented potential.
Alternative 4A – Same as Alternative 4 but uses sharper curves in order to align the road parallel to the MAX line.
- This alternative requires substantial acquisition of property with transit oriented potential.
- This alternative does not meet the minimum design standards for the curvature of the roadway.
Alternative 5 – Reconstructs the existing 170th Ave. & 173rd Ave. along Baseline Road with an increased number of turn lanes.
- This alternative would likely require acquisition of several new townhouses.
Alternative 6 (Couplet) - This alternative is a hybrid of alternatives #1 & #2 by using both 170th and 173rd and both transitions. However, because each segment would be only one-way, the right-of-way and associated traffic impacts would be shared among both roads. Each direction would be one lane.
For more information, contact:
Bill Ihly, Engineering Project Manager,
bill_ihly@co.washington.or.us
or (503) 846-7831
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