Innovative Intersections Presented By: Matt Crim P.E., PTOE Stantec Consulting Services Inc

Innovative Intersections Presented by: Matt Crim P.E., PTOE Stantec Consulting Services Inc. October 29, 2015

1 Traditional Intersections

Traditional Intersections allow left turns from all approaches. 1 2

There are four basic signal phases: 1. Left turns on Major St. 2. Throughs on Major St 3. Left turns on Minor St

4. Throughs on Minor St 3 4

2 Traditional Intersections… Phase, Phase, Everywhere a Phase

30% 20% 20% 30%

20% 50%

4 Phase Signal 30%

70% 30% 3 Phase Signal

2 Phase Signal

3 Traditional Intersection Safety

Angle crashes account for 40% of fatal crashes at intersections

Left turn crashes account for 20% of fatal crashes at intersections 32 Conflict Points

4 What Are Innovative Intersections?

Intersections that: • Improve the way traffic makes certain movements by eliminating, relocating or modifying conflict points • Improve the signalization by reducing cycle lengths and the number of phases • Improve travel time and reduce delay

5 Innovative Intersections

• Superstreets • Continuous Flow Intersection (CFI) • Diverging Diamond Interchange (DDI) • Single Point Urban Interchange (SPUI) • Median U-Turn Crossover • Roundabouts • Jughandle • Quadrant Intersection

6 Superstreet Intersections in the U.S. (aka J-Turn, Restricted Crossing U-Turn, Reduced Conflict Intersection)

States with Superstreet Intersections

Source: FHWA Restricted Crossing U‐Turn Informational Guide

7 Superstreet Intersection

Traditional Intersection

Superstreet Intersection

8 Superstreet Signal Phasing

Phase 1 Mainline • Mainline Through and Right-Turn

Side Street

Phase 2

Mainline • Mainline Left-Turn and U-Turn • Side Street Right-Turn

Side Street

9 Comparison of Conflict Points

Four-Leg Signalized Superstreet Conflict Type Intersection Intersection Merging/Diverging 16 12 Crossing (left turn) 12 2 Crossing (angle) 4 0 Total 32 14

10 Superstreet Safety Benefits

• Reduced collisions Collision Type Crash Reduction

for total, angle and Fatal and I njury 63% right turn, left turn, Angle and Right Turns 75% and fatal and injury Left Turns 59% Rear Ends 1% Sideswipes 13% • Total collisions Other 15% reduced by 46% Total 46% Source: N.C. State University Research Project 2009‐06

11 NC 87 @ Peanut Plant Road

NC 87 at SR 1150-Peanut Plant Rd

• NC 87 Bypass was opened in 1997 • 60 Total Crashes and 5 Fatal Crashes in 8 years after completion

12 NC 87 @ Peanut Plant Road Collision Diagram

13 NC 87 @ Peanut Plant Road

3 Years Prior to Superstreet: • 24 Total Crashes • 8 Crashes per Year • 19 T-Bone Crashes (w/Injury) • 6.33 Crashes per Year

1.5 Years After Superstreet: • 2 Total Crashes • 1.33 Crashes per Year • No T-Bone Crashes (w/Injury) • 0 Crashes per Year

14 Superstreet Semi-Trailer Accommodations

15 Superstreet Pedestrian Accommodations

Source: FHWA Restricted Crossing U‐Turn Informational Guide

16 Superstreet Pedestrian Safety

Source: FHWA Restricted Crossing U‐Turn Informational Guide

17 Superstreet Feasible Demands

Source: FHWA Restricted Crossing U‐Turn Informational Guide

18 Continuous Flow Intersection (CFI) (aka Displaced Left Turn or Crossover Displaced Left)

Major Street Movements

Minor Street Movements

19 CFI History

• Concept Developed over 30 years ago • AASHTO’s 2002 National Award for Innovation • Currently Constructed in • Colorado • Missouri • Louisiana • Ohio • Maryland • Texas • Mississippi • Utah • Under Design for Construction • Florida • North Carolina • Georgia • Virginia

20 CFI Basics

21 CFI Signal Phasing

Advance CFI Advance CFI Traffic Signal Traffic Signal

Center CFI Traffic Signal

Advance CFI Advance CFI Traffic Signal Traffic Signal

22 CFI Efficiency

Conventional 4-lane roadway CFI 4-lane roadway 650 v/l/h x 4 lanes = 2600 v/h 850 v/l/h x 4 lanes = 3400 v/h C=150 P.M. Peak C=120 P.M. Peak

23 Comparison of Conflict Points

Source: FHWA Signalized Intersections: Informational Guide

Four-Leg Signalized Partial CFI Conflict Type Intersection Intersection Merging/Diverging 16 14 Crossing (left turn) 12 6 Crossing (angle) 4 10 Total 32 30

24 Airline Hwy @ Sherwood Forrest Blvd CFI

Operational Benefits: Travel Times reduced by 40% Delay reduced by 50%

Crash Rate Reduction: From 10 per million vehicle miles (MVM) to 4 per MVM

25 Public Acceptance

Question: Do the improvements make TRAFFIC CONGESTION Better, Worse, or the Same?

26 Public Acceptance

Question: What is your level of Satisfaction with the current traffic conditions of the intersection?

27 Diverging Diamond Interchange (DDI) (aka Double Crossover Diamond)

28 Diverging Diamond Interchange (DDI)

29 Where did the DDI come from?

Le Perreux sur Marne, France Versailles, France

Seclin, France

30 DDI Signal Phasing

Phase 1

Phase 2

31 DDI Cost Benefits

DDI Cost Interchange Location Alternative Design Cost Cost Savings (real or estimated) I -44/Route 13 Springfield, MO $3.2 Million Ov er $10 Million $6.8 Million Diamond: $11.4 Million I -435/Front Street Kansas City, MO $6.7 Million $4.7 - 18.3 Million SPUI : $25 Million SR 265/SR 62 Utica, IN $52 Million $118 Million $66 Million SPUI : $10 Million I-590/Winton Road Brighton, NY $4 Million $6 - 9.6 Million Triple Left Diamond: $13.6 Million Retrofit New Interchange • Existing Bridge can usually be used • Fewer lanes than other interchange forms • Additional R/W rarely needed • Less bridge structure • Construction time is reduced • Less R/W than a cloverleaf • Maintenance of traffic simplified during construction

32 DDI Awards

• Popular Science’s Top 100 Innovations for 2009 • AASHTO’s 2010 National Award for Innovation

33 US 68 @ Kentucky 4 DDI

34 US 68 @ Kentucky 4 DDI

35 Comparison of Conflict Points

DDI • 2 crossing conflict points

Traditional • 4 crossing conflict points

36 US 68 @ Kentucky 4 DDI Safety

Pre DDI

Post DDI

37 Public Acceptance

Question: Overall, do you think this project was a good transportation solution for this location?

72%

38 Public Acceptance

Question: Do you think a DDI should be considered at other locations in Lexington or elsewhere in Kentucky?

Yes 72% No

39 6. Better access management

7. Attracts investment to revitalize struggling areas

8. Many designs are aesthetically pleasing

9. Improves quality of life

10. High return on investment 1. Better mobility enhances the local economy

2. Fewer conflicts and less congestion improve safety

3. Avoids street widening and even grade separation

4. Reduces right-of-way impacts

5. More feasible to convert general purpose lanes into other uses such as transit only lanes