When Roundabouts Are Counterproductive to Evacuation

When roundabouts are counterproductive to evacuation

In December 2023, Nevada State Governor Joe Lombardo directed the Nevada Department of Transportation (NDOT) to keep US 50 a four-lane thoroughfare from Stateline to Spooner Summit.  This modified NDOT’s US 50 East Shore Corridor Management Plan, or CMP, regarding lane configuration. However, other aspects of the CMP remain unaffected, including installation of two roundabouts (or traffic circles), one at the Lake Parkway intersection near Stateline and  the other at the SR28 intersection near Spooner Summit. This paper assesses whether roundabouts are justified in either location, based on criteria established by the Federal Highway Administration, and identifies significant design considerations.

We conclude that the proposed mini-roundabout at Lake Parkway is not justified based on wildfire evacuation capacity and geometric constraints. We conclude that the proposed large-scale roundabout at SR28 may be justified if two bypass lanes are included along the eastbound direction of US 50 and a third lane can be reconfigured for evacuation egress. However, we suggest considering an underpass configuration to minimize left-turn delays on SR28.

Read Roundabout Paper January 31, 2024

Photo by Lucas Miguel

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East Shore residents have been asking NDOT for serious modeling and simulation to demonstrate safety benefits of CMP. Here is their response.

What are your thoughts on the NDOT/TRPA plans for a road diet on US HWY 50?

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