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a TURN LANE DESIGN CHECKLIST (PAGE 1 OF 2) <br />�a <br />STEP 1 — DATA GATHERING <br />Location <br />State Roadway: Intersection: <br />))Left Turn Lane Design for Approach: N / S / W <br />0 Right Turn Lane Design for Approach: N / S / E / W <br />Vehicle Speed Choose one. Shown in order of preference. <br />Page 8-2 )Q- Design Speed:_ mph k-.,;u#%e, <br />❑ 85th Percentile Speed: mph <br />❑ Statewide Average Speed: _ mph (page B-2, Figure B-1) <br />Forecast Traffic Choose one. Shown in order of preference. <br />Volumes Design Year Volumes (provided by District/Central <br />Page s-3 U ice Planning Staff) <br />❑ Historic Volumes (existing volumes extrapolated to <br />estimate 20 year forecast volumes) <br />❑ 20-Year Multiplier (documented by State Aid and found <br />at the following website under County Reference Data: <br />httpJ1AAAmv dot. state, mn.us stateaidisa_csah.h[ml <br />Turning Volumes: see graphic at right, also note the <br />number of lanes for each movement. <br />Daily Volumes <br />Li <br />J 11. <br />r ,wZ <br />Major Street Daily Traffic Volumes: vehicles per day <br />Minor Street Daily Traffic Volumes: _ vehicles per day <br />Heavy <br />Commercial <br />Percent Heavy Vehicle: % (If percentage of heavy commercial is high special consideration should <br />Page 3-5 <br />be taken in Step 4 for deceleration and storage length of turn lane) <br />Grade <br />❑ Upgrade ❑ Downgrade <br />Page B-5 <br />Grade of approach: % (If greater than 3%, apply deceleration adjustment in Step 4) <br />Seasonal <br />Is there a large seasonal variation within the corridor (recreational routes, primary farm to market routes, etc)? If <br />Variations <br />yes, consider the variation and potential increase in traffic volumes during peak periods. Is it enough of an <br />Page a-4 <br />increase to change the design? ❑ Yes, adjust traffic volumes NO <br />Roadway <br />Is the intersection located on a horizontal curve? If yes, adjust taper in Step 4. (See Page B-17 and Table B-8) <br />Geometry and <br />Corridor <br />ElYes, on horizontal curve V No <br />Characteristics <br />Are there adjacent intersections that may influence the turn lane design? If yes, consider adjustments to the turn <br />Page a-s <br />lane design to better accommodate the constrained conditions. (See Pages B-23 and 24) <br />XYes, constrained location ❑ No <br />STEP 2 — DETERMINE FACILITY TYPE <br />Determine Rural vs. Urban (based on Access Management Category Assignments: <br />Facility Type <br />= I, ;;� Urban ❑ Rural <br />Expressway vs. Conventional (determined by Mn/DOT Office of Traffic, Safety and Technology) <br />❑ Expressway C� Conventional <br />Intersection ❑ Signalized: sec cycle length Unsignalized ❑ Future Signal? (see Figure B-3) <br />Control <br />Page B-9 <br />Development of Turn Lane Design Guidelines <br />