13 th Street and Dayton Avenue – Ames, IA Intersection Study ByungOck Kim Greg Karssen

13 th Street and Dayton Avenue - Location

13 th Street and Dayton Avenue – Lane Configuration 13 th STREET DAYTON AVEDAYTON AVE Approach #2 Approach # 4 Approach #3

13 th Street and Dayton Avenue – Images

Looking west Looking south Looking east Looking north

13 th Street and Dayton Avenue – Traffic Volumes Intersection ApproachLabel in Figure 2AADTLeft turnThruRight turn East Approach North Approach25933 West Approach South Approach45933

13 th Street and Dayton Avenue – Crash History Table 1: Crash Frequency Table 2: Crash Types MAJOR CAUSES (7) Failure to Yield ROW – Left Turn (4) Ran Traffic Signal (3) Following Too Close (Rear End) (2) Driving Too Fast for Conditions **Signalized intersection crashes…

Crash Diagram This diagram shows the major injury crashes were angle collisions involving a turning vehicle and a vehicle proceeding through the intersection

13 th Street and Dayton Avenue – Crash Countermeasures

13 th Street and Dayton Avenue – Recommendation #1 Left turn Signal phase –Evaluate signal times for left turns on EB/WB approaches –Provide exclusive left turns for NB/SB approaches…special concern for trucks and sight problems Looking north…imagine a truck here

13 th Street and Dayton Avenue – Recommendation #2 P-Turn, “quadrant intersections” –Unconventional turns –Two right turn movements (through- right-right) replace single left turn movement Follow vehicle on street B as it moves to street A Source: FHWA

13 th Street and Dayton Avenue – Recommendation #3 Offset Left Turn Lanes –Improves sight distance for left-turning vehicles –The left turning vehicle can see around the opposing left turning vehicle

Questions?? ?