Urban traffic modelling and intelligent intersection control

[2016-09-20 Tue 19:13:20] speaker: Yang Bo, IHPC event: Science in the Cafe

complex systems

• many components that interact with one another
• simple, decentralized interactions
• eg. flock of birds, bees, stampede in crowded area, landslide,
• spreading of disease, occurrence of traffic jam

next generation urban mobility at IHPC

• modelling of traffic flow

one dimensional driven system

• nearest neighbour
• anisotropic (only consider vehicle in front)
• non-linear
  • dissipative media

empirical observations

• density (veh/km) vs flow (veh/hour)
• free flowing -> traffic jam beyond a critical density
• time vs distance vs flow
• phantom jam due to human reaction time

microscopic models

• a_n(t + T) = c v_n(t + T)^l h_n^-m dv_n
• … many other possible models
• a_n: acceleration of nth vehicle
• h_n: headway
• v_n: velocity of nth vehicle
• dv_n: relative velocity of vehicle in front
• difficult to compare model and empirical results

video-taping of traffic flow with high frame rate camera

• along Queensway

traffic light optimisation

• GLIDE system in Singapore

• adaptive to real time demand

• creation of green wave

• difficult to adapt to fluctuating demand

• minimize average stational time per car

lightless intersection control

• traffic lights is centralized control
• feet-off -> hands/feet-off -> brain-off
• lightless control for feet-off vehicles
  • beacon that collects information of approaching vehicles
  • broadcast this to oncoming vehicles