College of Engineering Unit:
The City of Dallas, Oregon, requires an intersection improvement at SW Levens St and W Ellendale Ave. The intersection is currently a stop-controlled T- intersection near an elementary school, causing high queuing during pick-up and drop-off times. A city-designated truck route includes SW Levens St. and the east leg of W Ellendale Ave. This project aims to improve traffic flow; the goals to achieve this objective are to provide enough turning radius for heavy vehicle traffic and minimize queuing times.
Two design alternatives are considered for this project. Team LE1 Designed a signalized intersection, and Team LE3 designed a roundabout. Contributing disciplines for both teams include water resources, geotechnical, and traffic engineering. For the signalized intersection design, SW corner radius of Levens and Ellendale was changed to a curb radius of 52’. Working within the constraints of the right away reallocated lane widths to 10 ft and 11ft on Levens, and 12 ft lanes for Ellendale, in order to add 6 ft bike lanes. At the intersection we added 3 marked crosswalks along with 4 signals that operate in tandem with vehicle traffic signals. The final design includes 3 signal pole mast arms, two on the northside of Ellendale and one at the SE corner of the intersection. Four catch basins were added to the site, as well as a bioswale at the south west corner of the intersection. For the roundabout design, the final design choice is to transform the intersection into a concrete roundabout with catch basins for drainage and a retaining structure around the roundabout's central island. This will consist of three catch basins piped to the existing stormwater system. Implementing a 12ft travel lane width and a 12 ft mountable truck apron is used to ensure heavy vehicles have enough turning radius to clear the roundabout.
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 2023.expoposter.ce_.le_.01.03_0.pdf | 387.11 KB |