Text from 'Dynamic Late Merge Control Concept For Work Zones On Rural Freeways' PowerPoint Presentation
Slide 1
Dynamic Late Merge Control Concept For Work Zones On Rural Freeways
Slide 2
Photo of merging area on a freeway
Slide 3
Conventional Merge TCP
Diagram of a roadway with road signs associated with a conventional merge including: Road Work 2 Miles, Speed Limit 75 Fines Doubled, Right Lane Closed 1 Mile, Right Lane Closed 1/2 Mile, Reduced Speed Ahead, Speed Limit 55 Fines Doubled, End of Road Work Thank You Drive Safely.
Slide 4
Photo of freeway with conventional merge road signs
Slide 5
Photo of freeway with conventional merge road signs
Slide 6
Photo of a stretch of freeway
Slide 7
Photo of traffic merging
Slide 8
Basic Approaches
- Early Merge
- Late Merge
Slide 9
Early Merge
- Static
- Dynamic
Slide 10
Photo of road sign reading 'Right Lane Closed Ahead 5 Miles' on a freeway
Slide 11
Photo of rumble strips which are used to slow traffic
Slide 12
Merging arrow painted on the pavement
Slide 13
A 'Do Not Pass' sign on a freeway
Slide 14
Indiana Lane Merge
Diagram of a roadway with road signs associated with the Indiana Lane Merge which includes a series of three 'Do Not Pass When Flashing' (with LED Light-Solar Powered) within a 1/4-1/2 mile interval.
Slide 15
Photo of the 'Do Not Pass When Flashing' sign with solar powered LED lights
Slide 16
Line graph comparing the conventional merge with the Indiana Lane Merge. The Indiana Lane Merge traffic keeps a steady pace as it approaches the workzone (about 75% at 1800 ft), whereas conventional merge traffic slows considerably at approximately 48%, at the same distance from the workzone.
Slide 17
Forced Merges
- Indiana: 0.4/hour
- Conventional: 20/hour
Slide 18
Capacity
- Indiana: 1540 pcph
- Conventional: 1460 pcph
Slide 19
Late Merge
Photo of traffic approaching a late merge. Signs on both sides of the freeway read 'Use Both Lanes To Merge Point'.
Slide 20
Photo of truck approaching another late merge. Signs on both sides of the road read 'Merge Here Take Your Turn'.
Slide 21
Diagram of a roadway with road signs associated with a late merge including: Use Both Lanes to Merge Point, Road Work 1 Miles, CMS, Left Lane Closed 1/2 Mile 50 MPH, Left Lane Closed 1500 Ft 45 MPH, Left Lane Closed 1000 Ft 40 MPH, Merging Sign 40 MPH, Merge Here Take Your Turn, and a flashing arrow board.
Slide 22
The following is a line graph comparing forced merges involved in conventional merges and late merges in terms of number of merges per hour with the density of traffic (vpm). The conventional merge has 60 merges per hour at 80 vpm, while the late merge has 17 merges per hour at 80 vpm.
Slide 23
The following is a line graph comparing lane straddles involved in conventional merges and late merges in terms of number of straddles per hour with the density of traffic (vpm). The conventional merge has 14 straddles per hour at 80 vpm, while the late merge has 8 straddles per hour at 80 vpm.
Slide 24
Photo of a merge in progress
Slide 25
Photo of a merge in progress
Slide 26
Photo of a merge in progress
Slide 27
Photo of a merge in progress
Slide 28
Conclusions
- Early & Late Merge Performed Better Than Conventional Merge
- Lower Volumes:
Early Merge May Be Safer - Higher Volumes:
Late Merge May Be Safer
& More Efficient
Slide 29
Dynamic Late Merge
Diagram of a roadway with road signs associated with the Dynamic Late Merge which includes a series of three 'Use Both Lanes to Merge Point When Flashing' (with LED Light-Solar Powered) within a 1/4-1/2 mile interval.
Slide 30
Photo of flashing panel on the side of the road
Slide 31
Operational Issue
Illustration of a white car passing into the left lane on a busy street
Slide 32
Research Needed
- Volume Thresholds for Transition Between Early & Late Merge
- Driver Information Needs
- Warrants for Implementation
Slide 33
Sign reading 'End Road Work Thank You'
