WHY WE ARE CONCERNED ABOUT ROUNDABOUTS ON SR162 

 

ROUNDABOUTS WORK...

  • When traffic flow is at normal levels (not gridlocked levels)

  • With minimal truck traffic

  • With the majority of traffic flowing in a straight through direction

  • When there are few pedestrian, jogger and bicycle crossings

  • When there are few uncontolled access points to the highway and traffic allows spacing to safely enter the highway

  • These conditions ARE NOT FOUND on this corridor

TRAFFIC CONDITIONS 

  • This transportation corridor is currently in gridlock conditions during peak commuting hours

  • SR162 currently level “F” (fail) WDSOT highway peak hour rating

  • Tehaleh highway to add 1000 more cars per peak hour

COMMERCIAL TRUCK TRAFFIC ON SR162

  • Today’s commercial truck traffic consists of OVER 140 combination trucks PER HOUR

  • Currently over 1500 trucks of all types each day will be negotiating this roundabout with cars (most are tractor trailer combinations and this number will increase when the new road opens)

  • Truck combinations and vehicles do not mix well in roundabouts

HIGHWAY ACCESS AND EGRESS

  • Roundabouts meter exiting traffic evenly creating little spacing in traffic downstream

    • Breaks in traffic along corridor are necessary for access and egress to SR162

    • There are 140 access/egress points along SR162 between Sumner and Orting

    • Business patrons, farmers, and residents will experience dangerous conditions entering and leaving the highway

  • Traffic signals provide significant breaks in traffic to allow safe entry and exit

SR162 / 128th St E INTERSECTION

  • A majority of southbound evening traffic will be turning left onto the Tehaleh highway, stalling all northbound SR162 traffic from Orting

    • Lets do the math:  2000 going to Tehaleh-hr / 60 min = 33 vehicles per minute (that is 1 vehicle every 2 seconds making a left turn)

  • Vehicles within a roundabout have the right-of-way restricting entry

  • The size of roundabout intersection will be much larger than a signaled intersection requiring elimination of more properties and the McMillin rural neighborhood center zoning

FOOTHILLS TRAIL

  • The Foothills Trail parallels SR162 and connects with intersections at Military Road and at 128th St. E.

  • Mixing trail users with congested roundabout traffic creates a clear danger

  • Traffic signals provide designated passage periods for trail users and pedestrians

PEDESTRIAN CROSSINGS

  • Pedestrian crossings take place just outside of roundabout intersections

  • Pedestrian crossings cause interuptions to roundabout flow

  • Safety is a large concern when drivers attention is on heavy roundabout traffic

  • Roundabout crossings use safety islands between traffic lanes dividing the crossing process into two phases

  • Traffic signals provide a dedicated time for pedestrians crossing

VALLEY EVACUATION

  • SR162 is the only valley transportation corridor for valley evacuation

  • Coming center turn lane will add a third one-way lane during evacuation

  • However, a single lane roundabout will only accommodate two of those lanes of traffic causing an evacuation choke point

  • Disasterous situation!

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