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Traffic Jamboree: Factors Contributing to Phantom Jams. Jamie Ye, Eva Reyes, Brooks Wilding, Jack Lance, Zack Shen, Benjamin Nesselrodt , Stefan Joseph. Classic Scenario.
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Traffic Jamboree: Factors Contributing to Phantom Jams Jamie Ye, Eva Reyes, Brooks Wilding, Jack Lance, Zack Shen, Benjamin Nesselrodt, Stefan Joseph
Classic Scenario Stuck in a Jam? The Science behind Traffic. Digital Image. Evidence Based Living. Cornell University, n.d. Web. 29 July 2014
History • Car industry revolutionized lives of Americans • Came with many negatives • Traffic rules and regulations evolved with growth of transportation industry • Greenshields study in 1930s
Why it Matters • Cost • Environment • Public Health
Various Models • Microscopic Car-Following Models • Macroscopic Models • Gas-Kinetic Models • Cellular Automaton Models
Nagel-Schreckenberg • Freeway Traffic • Four Steps • Slow-to-Start Variant
Car locations when vmax = 135 km/h, ρ = 8.67 cars/km, and prob(slow) = 0.5 7.5 5.0 Position (km) 2.5 0 0 25 50 Time (min)
Phase Diagram Intermediate Transition Points Density (cars per kilometer) Velocity (km/hr)
Combined Phase Diagram 80 60 40 20 0 --- P = 0.25 P = 0.50 --- P = 0.75 Density (cars per kilometer) 20 40 60 80 100 120 Velocity (km/h)
Maximum Velocity (km/h)
Maximum Velocity (km/h)
Highway Density (cars/km)
Maximum Velocity (km/h)
Highway Density (cars/km)
Slow-to-start model Position (km) Time (min)
Maximum Velocity (km/h)
Highway Density (cars/km)
Conclusions:The Five Commandments of Traffic Jams • 1. Before vc , ρc: vmax = flux , density = flux . At or beyond vc , ρc: unstable, jams, variance • 2. For slow-to-start vc ≈ 180 km/h for all ρ, so for vmax< vc: vmax = flux • 3. Pushing vmax to unrealistic levels (>200 km/h): no benefit
The Five Commandments of Traffic (continued) • 4. As P(slow) increases, vmax and ρshow less effect on flux • 5. vmaxhas no apparent effect on speed of jam propagation
Relevance 80 60 40 20 0 Combined Phase Diagram --- P = 0.25 P = 0.50 --- P = 0.75 • London • M25 Motorway • Boston • Central Artery/Tunnel Project Density (cars per kilometer) 20 406080100120 Velocity (km/h)
Sources • Stuck in a Jam? The Science behind Traffic. Digital Image. Evidence Based Living. Cornell University, n.d. Web. 29 July 2014 • Hicks, Mark A. Stone Tablets – Clip Art Gallery. Digital Image. Stone Tablets – Clip Art Gallery. Discovery Education, n.d. Web 30 July 2014.
Acknowledgements Pennsylvania Governor’s School for the Sciences Dr. Barry Luokkala – PGSS Program Director Melissa Lessure – Assistant to the Director Zach McDargh – Team Project Advisor KaleighFelisberto– Teaching Assistant PGSS 2014 Teaching Assistants and Residence Life Directors • Pennsylvania Department of Education • PGSS Corporate Sponsors: EQT, AT&T, Teva Pharmaceuticals, PPG, Alcoa, Westinghouse • PGSS Private Sponsors • PGSS Alumni Association and PGSS Campaign, INC. • Carnegie Mellon University