Traffic wave

Presentor : Hsu, Hung-Wei

What is traffic wave?

Why is it important?

How does it appear?

  • Traffic Light
  • Cycle Effect
  • Lane Reduction​​

Important Factors

  • Reaction time
  • Variance between drivers
  • Density of cars

Model building

  • Safety distance d(v)
  • Constant acceleration
  • Variance of acceleration

Safety Distance

d_{safe}(v) \approx v + \frac{1}{2}a\frac{v^2}{a^2} =v+\frac{v^2}{2a}
dsafe(v)v+12av2a2=v+v22ad_{safe}(v) \approx v + \frac{1}{2}a\frac{v^2}{a^2} =v+\frac{v^2}{2a}
d_{acc}(v) \approx v + \frac{1}{2}a\frac{(a+v)^2}{a^2} =v+\frac{(a+v)^2}{2a}
dacc(v)v+12a(a+v)2a2=v+(a+v)22ad_{acc}(v) \approx v + \frac{1}{2}a\frac{(a+v)^2}{a^2} =v+\frac{(a+v)^2}{2a}

Traffic Light

Reaction time = 1

Reaction time = 10

Reaction  = 20

Speed - Reaction time

Cycle effect

Cycle effect

reaction time = 20

reaction time = 50

Reaction time

Cycle effect

a \sim gaussian(\mu, \sigma)
agaussian(μ,σ)a \sim gaussian(\mu, \sigma)
\sigma = 0
σ=0\sigma = 0
\sigma = 0.1\mu
σ=0.1μ\sigma = 0.1\mu
\sigma = 0.2\mu
σ=0.2μ\sigma = 0.2\mu

Density Effect

Threshold appears

Comparison

Reaction

Variance of  acceleration

Density

Lane Reduction

Low density

High density

Lane Reduction

Lane Reduction

Notice distance

Summary

  • Keep alert - reaction time
  • Don't be a strange driver
  • Don't drive during rush hour

final

By 許泓崴