Strategies

Strategies

We have developed five potential strategies to improve the predictable movement of people and goods along SR 161/31st Avenue SW. These strategies are presented below and not listed in order of priority. At the bottom of the page is an evaluation criteria table that compares the strategies. Click on the green bars to learn more about each strategy.

Strategy 1: Roadway and Intersection Improvements
This strategy would add roadway capacity west of the interchange by widening 31st Avenue SW between 94th Avenue E and the SR 512 westbound on-ramp to add a second westbound lane. It would also reconfigure the SR 512 eastbound off-ramp, providing a second option for making the right turn at the signal that would facilitate the merge to turn left onto northbound S Meridian and prevent drivers in the far-right lane from merging to S Meridian. The construction timeline would be relatively short compared to the other strategies.

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Overview: This strategy would add roadway capacity west of the interchange by widening 31st Avenue SW between 94th Avenue E and the SR 512 westbound on-ramp to add a second westbound lane. It would also reconfigure the SR 512 eastbound off-ramp, providing a second option for making the right turn at the signal that would facilitate the merge to turn left onto northbound S Meridian and prevent drivers in the far-right lane from merging to S Meridian. The construction timeline would be relatively short compared to the other strategies.

Benefits: Provides some additional roadway capacity and minor congestion relief at a low cost and with minor construction impacts.

Drawbacks: Does not include facilities designed for pedestrians and bicyclists, nor shoulder improvements for emergency vehicle passage.

Strategy 2: Roundabouts
This strategy would construct three roundabouts along 31st Avenue SW: one at the SR 512 westbound ramps, one at the SR 512 eastbound ramps and one at S Meridian. Roundabouts would provide additional capacity at the intersections without requiring a wider bridge and would reduce the severity of crashes at the intersections compared to traffic signals. The construction timeline would be longer than strategies 1 and 4, but shorter than strategies 3 and 5.

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Overview: This strategy would construct three roundabouts along 31st Avenue SW: one at the SR 512 westbound ramps, one at the SR 512 eastbound ramps and one at S Meridian. Roundabouts would provide additional capacity at the intersections without requiring a wider bridge and would reduce the severity of crashes at the intersections compared to traffic signals. The construction timeline would be longer than strategies 1 and 4, but shorter than strategies 3 and 5.

Benefits: Provides some additional roadway capacity and moderate congestion relief, and roundabouts reduce the severity of crashes. The roadway improvements would benefit emergency vehicles.

Drawbacks: Does not include facilities designed for pedestrians and bicyclists.

Strategy 3: Bridge Widening and Nonmotorized Facilities
This strategy would widen the 31st Avenue SW bridge over SR 512 to add roadway capacity and sidewalks on one side of the bridge. Option A would add sidewalks on the south side of 31st Avenue SW. Option B would add sidewalks on the north side of 31st Avenue SW. Optional elements include adding connecting bicycle lanes where 31st Avenue SW intersects with 94th Avenue E and S Meridian and widening the SR 512 westbound on-ramp right turn lane. The eastbound off-ramp would also be modified so that drivers make a right turn from the signal, eliminating the difficult weave maneuver between the eastbound off-ramp and northbound S Meridian.

Click image to zoom.

Overview: This strategy would widen the 31st Avenue SW bridge over SR 512 to add roadway capacity and sidewalks on one side of the bridge. Option A would add sidewalks on the south side of 31st Avenue SW. Option B would add sidewalks on the north side of 31st Avenue SW. Optional elements include adding connecting bicycle lanes where 31st Avenue SW intersects with 94th Avenue E and S Meridian and widening the SR 512 westbound on-ramp right turn lane. The eastbound off-ramp would also be modified so that drivers make a right turn from the signal, eliminating the difficult weave maneuver between the eastbound off-ramp and northbound S Meridian.

Benefits: Provides some additional roadway capacity and minor congestion relief, and includes facilities designed for pedestrians and bicyclists, including sidewalks on one side of the bridge (i.e., Option A: Southern sidewalk or Option B: Northern sidewalk) and roadway improvements that would benefit emergency vehicles.

Drawbacks: Would take longer to construct than the other strategies, and construction activities related to modifying the existing bridge could have a greater effect on traffic than the other strategies.

Strategy 4: Loop Ramp
This strategy would eliminate the left turn to the eastbound on-ramp and replace it with a right turn to a new loop on-ramp. Switching the left turn to a right turn allows drivers a free flow movement to the on-ramp, and the removal of the left turn would improve eastbound and westbound traffic flow through the intersection. The right turn to the existing on-ramp would be maintained.

Click image to zoom.

Overview: This strategy would eliminate the left turn to the eastbound on-ramp and replace it with a right turn to a new loop on-ramp. Switching the left turn to a right turn allows drivers a free flow movement to the on-ramp, and the removal of the left turn would improve eastbound and westbound traffic flow through the intersection. The right turn to the existing on-ramp would be maintained.

Benefits: Provides some additional capacity and minor congestion relief. Would take less time to construct than the other strategies.

Drawbacks: Does not include facilities designed for pedestrians and bicyclists, nor shoulder improvements for emergency vehicle passage.

Strategy 5: Flyover Ramp
This strategy would construct a flyover ramp to directly connect traffic on the SR 512 eastbound off-ramp to the intersection of 31st Avenue SE and S Meridian, eliminating the eastbound weave between the eastbound off-ramp and northbound S Meridian. The existing ramp would remain, and the new ramp would be constructed over the top of 31st Avenue SW and the SR 512 eastbound on-ramp.

Click image to zoom.

Overview: This strategy would construct a flyover ramp to directly connect traffic on the SR 512 eastbound off-ramp to the intersection of 31st Avenue SE and S Meridian, eliminating the eastbound weave between the eastbound off-ramp and northbound S Meridian. The existing ramp would remain, and the new ramp would be constructed over the top of 31st Avenue SW and the SR 512 eastbound on-ramp.

Benefits: Adding a new ramp eliminates eastbound weaving traffic between the SR 512 eastbound off-ramp and northbound S Meridian.

Drawbacks: Does not include facilities designed for pedestrians and bicyclists, nor shoulder improvements for emergency vehicle passage. Construction would take longer than the other strategies.

Strategy Comparison Table

The table below is intended to provide a snapshot of the strategies in comparison to each other. The relative comparisons were developed based on traffic models and other analysis of the five strategies.

Key to ranking: Good rank Good Fair rank Fair Poor rank Poor

    Strategy 1: Strategy 2: Strategy 3: Strategy 4: Strategy 5:
    Roadway and Intersection Improvements Roundabouts Bridge and Nonmotorized Facilities Loop Ramp Flyover Ramp
MULTIMODAL Includes pedestrian improvements Poor rank Poor rank Good rank Poor rank Poor rank
Includes bicycle improvements Poor rank Poor rank Good rank Poor rank Poor rank
Accommodates emergency vehicles Poor rank Poor rank Poor rank
MOBILITY Improves traffic flow Good rank Poor rank
Improves travel times Poor rank
Reduces traffic backups Good rank Poor rank
Makes lane changes easier Good rank Poor rank
SAFETY Improves safety Good rank
PROPERTY Constructed in public right of way Good rank Poor rank
CONSTRUCTABILITY Minimizes impact to traffic Poor rank Poor rank Good rank
Minimizes length of construction Good rank Poor rank Poor rank
Minimizes cost Good rank Poor rank Poor rank
MAINTENANCE Requires no additional maintenance Good rank Good rank Good rank Good rank

Key to ranking: Good rank Good Fair rank Fair Poor rank Poor

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Please share your thoughts

Please make sure to click on the submit button below to submit your survey responses and comments.

1.
How frequently do you travel along SR 161/31st Avenue SW over SR 512?

2.
Do you purposely time your trips to avoid peak commute hours?

3.
Do you take an alternate route to avoid driving on SR 161/31st Avenue SW over SR 512?

4.
Which of the following elements are important to you? (Please select 3.)

5.
If bicycle lanes were available along SR 161/31st Avenue SW near SR 512, would you use them on a regular basis?

6.
If sidewalks were available along SR 161/31st Avenue SW near SR 512, would you use them on a regular basis?

7.
Please tell us about your top two strategy choices.

8.
Do you have other ideas on how to improve traffic flow through the area?