Tuesday, June 16, 2020

Diverging diamond interchange: How they work

By Doug Adamson

We’ve been talking about the Marvin Road diverging diamond interchange in Lacey for quite a while but now it’s time to really get serious. The new layout is scheduled to open up this year and it’s definitely time to prepare.

While a diverging diamond interchange is intuitive for travelers, we also want everyone to get a better idea of how it works. At first glance, it may appear complicated, but  there’s nothing new to learn. You come to a stoplight and you stop. Then you follow traffic signals, signs, and lines through the interchange. Carefully designed roadway striping, arrows, and signs direct travelers. A concrete barrier in the middle of the overpass will provide access for pedestrians and bicyclists.
A key feature of this new layout is increased efficiency. Drivers make a free left turn onto the highway on-ramps without stopping at a traffic signal.

A diverging diamond interchange removes what are called conflict points. A conflict point is an area of roadway where vehicles cross, merge, or diverge. The enhanced Marvin Road interchange in Lacey will reduce the conflict points from the existing 26 to 14. This helps to improve the safety at this busy interchange.

Get additional information at I5exit111.com where you can find virtual walk-through and drive-through videos, as well as project updates.