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Arizona Office 20 Crimson Vista Lane Sedona, AZ 86351 (928) 284 -0295 www. roundabouts. Arizona Office 20 Crimson Vista Lane Sedona, AZ 86351 (928) 284 -0295 www. roundabouts. us [email protected] us Presents: Latest Roundabout Planning & Design Challenges Roundabout Specialist: Scott Ritchie, P. E. , President

Latest Planning/Design Challenges Thank You to Ed Rice, Jeff Shaw, Hillary Isebrands, & Others Latest Planning/Design Challenges Thank You to Ed Rice, Jeff Shaw, Hillary Isebrands, & Others On FHWA & ITE Team for Providing NE Rbt Peer Exchange… – Excellent Program! – Most Attendees Very Rbt Savvy – Good Collective Knowledge Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US

Latest Planning/Design Challenges I Don’t Teach “…fillet, radius, fillet, offset, fillet… in 20 minutes Latest Planning/Design Challenges I Don’t Teach “…fillet, radius, fillet, offset, fillet… in 20 minutes you’re done!” – “…the devil is in the details wherein it takes someone else 3 months to finish the design” I’m the Guy Who ‘Starts & Finishes the Design’ – …as a Subconsultant to Jurisdiction or Local Firm ‘Roundabouts Gaining Ground’ (USA Today) Why American Drivers Should Learn To Love the Roundabout (Slate Magazine, Tom Vanderbilt) States Embracing Roundabouts Planning of Rbt Corridors is Up Community Involvement & Acceptance is Up Growing Popularity = Everyone Trying One… Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US

Latest Planning/Design Challenges Yesterday, I Heard A Lot Jurisdictions Speak on Rbts The Knowledge Latest Planning/Design Challenges Yesterday, I Heard A Lot Jurisdictions Speak on Rbts The Knowledge Was Good! Yet # of Rbts Still Very LOW (Rbt Inventory Listed) Most Were SLR (Few MLR) Design Issues Described Were: – – – Extg ROW Constraints Trucks Operations Lack of Rolled Curbs Maintenance Issues Due to Snow Plows Public Acceptance: Stigma of Old Rotaries & Traffic Circles All of These Issues Can Be Addressed (Later) But, There’s Still Rbts Built w/ Significant Design Issues, Planning Flaws, Unresolved Geometric Design Challenges! Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US

Latest Planning/Design Challenges Issues Mostly Due to Designer or Jurisdictional Compromises – Nothing New Latest Planning/Design Challenges Issues Mostly Due to Designer or Jurisdictional Compromises – Nothing New Here… Most Common Deficiencies: – Lack of Deflection (#1 Key / Design Principle) – ICD’s (Dia / Size / Shape) Not Ideal / Optimized – Not Site Specific Design / Alternative Solution – Trucks Disfunctional (State or Oversize) – Not Applying Sound Rbt Design Principles – No Sustainability in Planning & Design – Technically Correct, But Lacks Composition (Confusion) Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US

Planning & Design Challenges Personally Designed Over 300 Rbts in the U. S. – Planning & Design Challenges Personally Designed Over 300 Rbts in the U. S. – 200+ Built, 150+ Multi-Lane Roundabouts, 160+ State/Fed Hwys Yet Still Learning, Adapting Techniques, & Evolving Design – Share these Experiences! Also… Give Helpful Tips & a Few Examples Showing How Your Rbts Should Be Developed/Retrofitted or Improved… – saves big $ in the long run #1… Get Out and Drive ‘em! What Does it FEEL Like / How Does it Drive? – Abrupt, Too Tight with Path Overlap, & Awkward? – Too Fast, Sudden Stops, or No Deflection? OR… – Smooth, Slow, & Comfortable? (Publicly Accepted) Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US

#2: Focus on Principles Good Rbt Design has: – Sound Engineering Practices – Calculated #2: Focus on Principles Good Rbt Design has: – Sound Engineering Practices – Calculated Capacity – Measurable Safety (checks) – Proper Deflection – Balanced Speeds (~25 mph) – Truck Capabilities (in-lane? ) – Multi-Modal Facilities (ped/bike) – No Entry Path Overlap – Within Project Constraints – Conform to Local Regs Good Roundabout Design has: – Good Composition – Based on Design Principles – Optimized Lane Config-safe – Comfortable to Drive – Smooth Entries and Exits – Site Specific Design (no cookie cutter) – Properly Sized/Placed ICD – Safe & ‘Easy’ for the Public 222 – Positive Driving Experience – Sustainable Design Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US

#3: Don’t Stop At Guides/Stds Roundabouts 100% ? 0% THINK ZONE (Challenges & Solutions) #3: Don’t Stop At Guides/Stds Roundabouts 100% ? 0% THINK ZONE (Challenges & Solutions) Rbt Guides & Standards Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US

#4: Understand Trade Offs The Focus on “Standards” Hinders the Creative Process & Prevents #4: Understand Trade Offs The Focus on “Standards” Hinders the Creative Process & Prevents the Finding of an Optimized Solution! Balance Between Capacity, Safety, Cost (Sustainable) – Can Lead to Multiple Alternative Solutions… – Often Aims Conflict (Gov’t: ROW/Capacity; Designer: Truck/Speed) Traffic Volumes Safety Geometric Layout Accidents Queues Delays Your Project Here? AT A COST Explore Objective Triangle for Optimum Trade-off Capacity Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE Cost WWW. ROUNDABOUTS. US

#5: Ensure Holistic Implementation Balance is Crucial… Balance the Competing Aims: – Can be #5: Ensure Holistic Implementation Balance is Crucial… Balance the Competing Aims: – Can be Iterative Process with Constraints (Planning & Engineering) We Must Visualize & Review the Rbt as a Whole! – Holistic Design = Balance (Cap, Safety, Cost - All) Common Sense Planning & Engineering Practices Focused on the Principles of Rbts, as well as Plenty of Experience and Design Practice are Essential! – Some Jurisdictions Req 50+ MLR Design Experience to Work Field Time w/Rbt Also Key (Nothing Replaces Real World Exp) To Obtain Optimal Solution (Unique / Multiple Alts), We Must Use BOTH Sound Engineering Practices AND a Holistic Design Approach We Must Use BOTH Left & Right Sides of the Brain! Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US

Holistic Design: Two Hemispheres of Thinking Which Way is the Figure Rotating? Counterclockwise? Clockwise? Holistic Design: Two Hemispheres of Thinking Which Way is the Figure Rotating? Counterclockwise? Clockwise? (LT Arm & LT Leg Out) (RT Arm & RT Leg Out) Video of Rotating Figure Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US

Holistic Design Shifting Your Brain’s Current? Counterclockwise or Facing Backward: (LT Arm & LT Holistic Design Shifting Your Brain’s Current? Counterclockwise or Facing Backward: (LT Arm & LT Leg Out) Left Brain – – – Logical Sequential Rational Analytical Objective Looks at Parts! Clockwise or Facing Forward: (RT Arm & RT Leg Out) Right Brain – – – Holistic Intuitive Random Subjective Looks at Wholes! Holistic Designers Can See It BOTH Ways Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US

#6: Get Rbt Concept Checked ! Don’t Accept Just a Circle w/ Leg’s Tied #6: Get Rbt Concept Checked ! Don’t Accept Just a Circle w/ Leg’s Tied In. . . Never Constrain Creativity to Identify Optimal Solution – Open Your Mind to Better Solutions / Possibilities… Design Should Be Unique to Site to Achieve its Highest Possible Safety, Capacity, and Cost Effectiveness – In the End PUBLIC ACCEPTANCE Matters! Check the Design’s Composition (Does it Flow? How Will it Drive? ) Obtain a Thorough Design Review (Holistic & Specific Details) Require a Peer Reviewer or Qualified Designer(s) – Many States Already Do… Let’s Discuss Examples (Design Challenges & Solutions) Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US

Challenge: Holistic Design ROW – Size? Res & Com Accesses – Layout? Deflection? – Challenge: Holistic Design ROW – Size? Res & Com Accesses – Layout? Deflection? – Speeds? – Operation? Composition? See Issues Here? Anyone Marcola/Martin, Springfield, OR Original Design Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE (by others) WWW. ROUNDABOUTS. US

Solution: Holistic Design This Would Fail the Std Template Test! Yet it Fits and Solution: Holistic Design This Would Fail the Std Template Test! Yet it Fits and Works! Marcola/Martin, Springfield, OR REVISED Design Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE (by RTE) WWW. ROUNDABOUTS. US

Challenge: Capacity vs. Cost 1350 SB Rights, Low Left Turns SB Bypass Lane Required Challenge: Capacity vs. Cost 1350 SB Rights, Low Left Turns SB Bypass Lane Required HCM Sat Flow Rate =1750 Single or Double? Two Lane Bypass! Snagged or Full? North Video: Cotton Lane / Estrella Pkwy, Goodyear, AZ Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US

Solution: Capacity vs. Cost Interim Opening of Cotton Lane / Estrella Pkwy, Goodyear, AZ Solution: Capacity vs. Cost Interim Opening of Cotton Lane / Estrella Pkwy, Goodyear, AZ Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US

Challenge: Capacity vs. Safety 450 vph SB Approach 1400 vph Circulating Single Lane Approach Challenge: Capacity vs. Safety 450 vph SB Approach 1400 vph Circulating Single Lane Approach OR is it? ? ? Original Design (By Others) SR 89 A / Black Hills Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US

Thinking Through Capacity Entry Flow + Circulating Flow (Qc) < ~1400 to 1800(max) ~ Thinking Through Capacity Entry Flow + Circulating Flow (Qc) < ~1400 to 1800(max) ~ Single Lane Approach 1400 + 450 = 1850 vph TWO Lane Approach Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US

Solution: Capacity vs. Safety 450 vph SB Approach 1450 vph Circulating Single Lane Approach? Solution: Capacity vs. Safety 450 vph SB Approach 1450 vph Circulating Single Lane Approach? Two Lane Approach Required! SR 89 A / Black Hills, Clarkdale, AZ Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US

Solution: Capacity vs. Safety Under Construction, 2008, SR 89 A / Black Hills, Clarkdale, Solution: Capacity vs. Safety Under Construction, 2008, SR 89 A / Black Hills, Clarkdale, AZ Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US

Challenge: Corridor Sustainability Case Study in Insurance Institute of Highway Safety Study on Roundabout Challenge: Corridor Sustainability Case Study in Insurance Institute of Highway Safety Study on Roundabout Corridors Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US

Solution: Corridor Sustainability Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Solution: Corridor Sustainability Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US

Solution: Corridor Sustainability Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Solution: Corridor Sustainability Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US

Challenge: Acute Angles Existing Intersection SLR Required US 191 / SR 264, Ganado, AZ Challenge: Acute Angles Existing Intersection SLR Required US 191 / SR 264, Ganado, AZ Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US

Thinking Through Acute Angles Existing Truck Movements US 191 / SR 264, Ganado, AZ Thinking Through Acute Angles Existing Truck Movements US 191 / SR 264, Ganado, AZ Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US

Thinking Through Acute Angles 140’ ICD Circle US 191 / SR 264, Ganado, AZ Thinking Through Acute Angles 140’ ICD Circle US 191 / SR 264, Ganado, AZ Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US

Thinking Through Acute Angles 200’ ICD Circle US 191 / SR 264, Ganado, AZ Thinking Through Acute Angles 200’ ICD Circle US 191 / SR 264, Ganado, AZ Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US

Solution: Acute Angles Elliptical ICD US 191 / SR 264, Ganado, AZ Scott Ritchie, Solution: Acute Angles Elliptical ICD US 191 / SR 264, Ganado, AZ Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US

Add BUILT Ganado photos Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. Add BUILT Ganado photos Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US

Challenge: Sustainability / Costs Planning for Growth Interim Conditions Freeway to Freeway Interchange US Challenge: Sustainability / Costs Planning for Growth Interim Conditions Freeway to Freeway Interchange US 93 / SR 89, Wickenburg, AZ Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US

Solution: Sustainability / Costs Planning for Growth Ultimate Conditions Freeway to Freeway Interchange US Solution: Sustainability / Costs Planning for Growth Ultimate Conditions Freeway to Freeway Interchange US 93 / SR 89, Wickenburg, AZ Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US

Solution: Sustainability / Costs Planning for Growth See Caltrans Website of Expandable Design at Solution: Sustainability / Costs Planning for Growth See Caltrans Website of Expandable Design at SR 138 / Palmdale Blvd http: //www. dot. ca. gov/dist 07/travel/projects/roundabout/ Cost Savings for Ultimate Growth Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US

Design Challenge for Trucks Wickenburg US 93/SR 89 STAYING IN LANE ALL THE WAY Design Challenge for Trucks Wickenburg US 93/SR 89 STAYING IN LANE ALL THE WAY THROUGH!!! WB-67 Stays In Lane THROUGH Roundabout (Outside Lane) US 93 / SR 89, Wickenburg, AZ Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US

Design Challenge for Trucks Some Say This Can’t Wickenburg US 93/SR 89 STAYING INBe Design Challenge for Trucks Some Say This Can’t Wickenburg US 93/SR 89 STAYING INBe Done Without More LANE ALL THE WAY THROUGH!!! Impacts… WB-67 Stays In Lane THROUGH Roundabout (Inside Lane) Really? US 93 / SR 89, Wickenburg, AZ Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US

Challenge: DOT Truck Req’t Joint State Transportation Design Study Underway: – Rbts & Std Challenge: DOT Truck Req’t Joint State Transportation Design Study Underway: – Rbts & Std Large Trucks (Wis. DOT/Mn. DOT) ‘Synthesis of Current Design Practices’ – Case 1: MLR Trucks NOT Accommodated in Lane – Case 2: MLR Trucks Stay In Lane In Entry – Case 3: MLR Trucks Stay In Lane In Entry & Circle Collecting Data Nationwide & Coord. Truck Assoc. Develop Design Guidelines for Accom. Trucks @ MLRs Develop Graphics & Guidance Materials for CDM Implementation Recommendations & Future Research Current FDM Rbt Guide is Wrong…Needs Updating… Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US

Solution: Case 1 Trucks Section to Be Updated… This Method Work with 10% Trucks? Solution: Case 1 Trucks Section to Be Updated… This Method Work with 10% Trucks? May Work Now, But in 10 yrs? If Cars Queued Up… – Can Trucks Make Turn? – Low Traffic/Low %=Okay? – Public Acceptance? – SR Field Tests Show Poor Operations! – DOT’s Starting to Require Better… Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US

Solution: Case 1 Trucks Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. Solution: Case 1 Trucks Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US

Solution: Case 2 Trucks Guide’s TEXT was Opinion at the Time… – Now NOT Solution: Case 2 Trucks Guide’s TEXT was Opinion at the Time… – Now NOT Supported By DOT TEXT is NOT Supported By Facts “Geometry Must Be Larger”? ~ Nope “Possibly Resulting in Increased ROW, Costs, Crashes”? ~ Nope! Is Why ‘Truck Study and Guide’ Updates… Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US

Solution: Case 3 Trucks WB-67 Stays In Lane (Outside Lane) Scott Ritchie, Roundabouts & Solution: Case 3 Trucks WB-67 Stays In Lane (Outside Lane) Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WB-67 Stays In Lane (Inside Lane) WWW. ROUNDABOUTS. US

Challenge: Path Overlap Example of Entry Path Overlap Designer Followed Bad Guidance… Scott Ritchie, Challenge: Path Overlap Example of Entry Path Overlap Designer Followed Bad Guidance… Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US

Challenge: Path Overlap Does NOT Work w/out Good Entry Design Does NOT Ensure No Challenge: Path Overlap Does NOT Work w/out Good Entry Design Does NOT Ensure No Path Overlap! Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US

Challenge: Path Overlap Has 4. 5’ Offset from CID… (per Guide) Has 40’ Tangent Challenge: Path Overlap Has 4. 5’ Offset from CID… (per Guide) Has 40’ Tangent Length… (per Guide) Result? See next slide… Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US

Challenge: Path Overlap Designer Followed State Guide… Still Results in Entry Path Overlap!! Issue: Challenge: Path Overlap Designer Followed State Guide… Still Results in Entry Path Overlap!! Issue: Poor Entry Design Severe Entry Path Overlap!!! Designer & Guide Need Updating! Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US

Solution: Path Overlap No Entry Overlap! Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Solution: Path Overlap No Entry Overlap! Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US

Interim to Ultimate Solution Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. Interim to Ultimate Solution Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US

Path Overlap? Tight / Abrupt Entries and Exits Do NOT Work for MLRs! Scott Path Overlap? Tight / Abrupt Entries and Exits Do NOT Work for MLRs! Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US

Solution: Put It All Together Addressing Multiple Issues Together Deflection Achieved Optimized ICD (dia/size/shape) Solution: Put It All Together Addressing Multiple Issues Together Deflection Achieved Optimized ICD (dia/size/shape) Site Specific Design Trucks Accommodated (stay in lane in entry) Sound Design Principles Sustainable Design US 60 / US 93, Wickenburg, AZ Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE Built 2009 WWW. ROUNDABOUTS. US

Planning & Design Challenges Different Types of Rbt Require Diff Design Techniques Different Design Planning & Design Challenges Different Types of Rbt Require Diff Design Techniques Different Design Methods Apply to Different Situations Different Site Issues/Req’mts = Different Solutions Goal: Slow Drivers Down But w/o Knowing It for a Safer Driving Experience w/ Minimal Accidents – (Fender Benders Are Reduced) A Better/Smoother Design… THIS is the Latest Design Challenge! Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US

Roundabout Questions: Scott Ritchie, P. E. , President Roundabouts & Traffic Engineering www. roundabouts. Roundabout Questions: Scott Ritchie, P. E. , President Roundabouts & Traffic Engineering www. roundabouts. us (928) 284 - 0295 Designing & Implementing Roundabouts Nationwide ! Scott Ritchie, Roundabouts & Traffic Engineering (RTE) FHWA/ITE Northeastern U. S. Roundabout Peer Exchange, © RTE WWW. ROUNDABOUTS. US