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TURN LANE DESIGN CHECKLIST (PAGE 1 OF 2) <br />STEP 1 — DATA GATHERING <br />Location J_ <br />State Roadway: Intersection. e <br />I -Left Turn Lane Design for Approach: N / S � W <br />1-1 Rig lit Turn Lane Design for Approach: N / S / E / W <br />Vehicle Speed Choose one. Shown in order of preference. d� i <br />Page 8.2 11!5(Pesign Speed: q to mph A 5;5 " "" t- ry.� <br />❑ 85'h Percentile Speed: mph <br />Forecast Traffic <br />Volumes <br />Page B-3 <br />Heavy <br />Commercial <br />Page B-5 <br />Grade <br />Page B-5 <br />Seasonal <br />Variations <br />Page B-4 <br />Roadway <br />Geometry and <br />Corridor <br />Characteristics <br />Page B-6 <br />Determine <br />Facility Type <br />Page B-d <br />Intersection <br />Control <br />Page 8-.9 <br />❑ Statewide Average Speed: mph (page B-2, Figure B-1) <br />Choose one. Shown in order 'of ence <br />X Design Year Volumes (provided by District/Central <br />Office Planning Staff) 7,02Z <br />o <br />❑ Historic Volumes (existing volumes extrapolated to <br />estimate 20 year forecast volumes) <br />�-J 1 L <br />❑ 20-Year Multiplier (documented by State Aid and found <br />at the following website under County Reference Data: <br />11 <br />1 <br />http:/hwww dot state.mn us/stateaid/sa_csah,html <br />Turning Volumes: see graphic at right, also note the <br />l <br />number of lanes for each movement. <br />Daily Volumes <br />Major Street Daily Traffic Volumes: tYj vehicles per day <br />Minor Street Daily Traffic Volumes: �_ vehicles per day <br />Percent Heavy Vehicle: I % (If percentage of heavy commercial is high special consideration should <br />be taken in Step 4 for deceleration and storage length of turn lane) <br />❑ Upgrade ❑ Downgrade <br />Grade of approach:_% (If greater than 3%, apply deceleration adjustment in Step 4) <br />Is there a large seasonal variation within the corridor (recreational routes, primary farm to market routes, etc)? If <br />yes, consider the variation and potential increase in traffic volumes during peak periods. Is it enough of an <br />increase to change the design? ❑ Yes, adjust traffic volumes >( No <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 />❑ Yes, on horizontal curve A No <br />Are there adjacent intersections that may influence the turn lane design? If yes, consider adjustments to the turn <br />lane design to better accommodate the constrained conditions. (See Pages B-23 and 24) <br />EI; Yes, constrained location ❑ No <br />STEP 2 — DETERMINE FACILITY TYPE <br />Rural vs. Urban (based on Access Management Category Assignments: <br />LXUrban ❑ Rural <br />Expressway vs. Conventional (determined by Mn/DOT Office of Traffic, Safety and Technology) <br />❑ Expressway Conventional <br />❑ Signalized: sec cycle length ^ Unsignalized ❑ Future Signal? (see Figure B-3) <br />Development of Turn Lane Design Guidelines <br />