Okay, so I’m assuming speeding on roadways is illegal in most countries, and that driving through a red light is also illegal. Okay? Okay. Let’s talk about blue shift. Blue shift is an application of the Doppler effect to light. Basically, if you travel in the direction opposite a wave, the apparent frequency of said wave increases, and the opposite is true if you travel in the same direction as the wave, the apparent frequency decreases. Since blue has a high frequency and red has a low frequency (as far as light goes) light is blue shifted when moving toward the light source. So now that that’s taken care of, how fast would you need to be going to see a red light at an intersecti0n as a green light. Using the speed of light, a frequency for red light (4.4*10^14 Hz), a frequency for green light (6*10^14 Hz), and Wolfram|Alpha, we get a speed of about 3/10 of the speed of light. That’s fast.