Appendix D Traffic Impact Analysis - westplainseis.com

Hwy 2 / Lundstrom: Restripe and widen approaches to accommodate exclusive NB and SB right
turn lanes.
Project Proportional Share: 29.4%
Resulting LOS & Delay (sec): F/179.6
Hwy 2 / Garfield: Optimize signal timing.
Project Proportional Share: 23.7%
Resulting LOS & Delay (sec): D/52.5
Hwy 2 / Hayford: Optimize signal timing and consider converting the inside SB thru land to a
2 nd SB left turn lane. Widen the EB and NB approaches for exclusive right turn lanes. Restripe
the wide paved median for a 2 nd WB left turn lane. Add 2 nd NB left turn lane. Alternatively, add
a 2 nd NB left turn lane and a WB auxiliary lane.
Project Proportional Share: 18.0%
Resulting LOS & Delay (sec): F/97.1 / D/51.3 (alternative)
Craig / SR 902: Install traffic signal or consider installation of a roundabout.
Project Proportional Share: 31.1%
Resulting LOS & Delay (sec): B/17.6 / B/10.4 (roundabout)
Hwy 2 / Middle Driveway: Install traffic signal and approach improvements (SB Middle
Driveway); install a WB right turn lane. Alternatively, consider installation of a roundabout.
Project Proportional Share: 100%
Resulting LOS & Delay (sec): D/45.4 / E/61.3 (roundabout
Craig / Sixth Ave.: Widen the intersection approach to provide and exclusive NB right turn lane.
Project Proportional Share: 38.0%
Resulting LOS & Delay (sec): D/28.8
Suggested intersection lane geometry for Alt. 1, PH3 (buildout conditions) at Middle Dwy./Hwy.2 and
Craig Rd./Hwy.2 can be seen on Figure 24. Note that at the design stage consideration of or
accommodation for a future 4 th leg (southerly leg) of the Middle Dwy./Hwy 2 should be examined.
Alternative 2
Recommended improvements are summarized below along with the estimated proportional fair share
contribution.
Hwy 2 / Craig: Install traffic signal and widen the NB and SB approaches to provide and
exclusive left turn lane. Alternatively, consider installation of a roundabout.
Project Proportional Share: 34.2%
Resulting LOS & Delay (sec): C/31.6 / A/7.8
Hwy 2 / Hayford: Optimize signal timing and convert the inside SB thru lane to a 2 nd SB left
turn lane.
Project Proportional Share: 15.8%
Resulting LOS & Delay (sec): D/45.9
Craig / SR 902: Install traffic signal or consider installation of a roundabout.
Project Proportional Share: 23.7%
Resulting LOS & Delay (sec): B/15.6 / A/8.6 (roundabout)
Hwy 2 / Middle Driveway: Install traffic signal and approach improvements (SB Middle
Driveway); install a WB right turn lane. Alternatively, consider installation of a roundabout.
Project Proportional Share: 100%
Resulting LOS & Delay (sec): C/31.1 / A/9.8 (roundabout)
West Plains Development – Spokane Tribe Page | 6
Traffic Impact Analysis April 28, 2011