Comment by ajmurmann

Clearly both are a factor but you don't need both. Even if I go 20mph I have to slam on the breaks hard if the light turns when I'm just three ft away. The only way around this is to treat every light like a stop sign where you do a California roll

Edit: As a related pet peeve I've never understood why we don't have countdowns for car traffic lights like we do for pedestrians. These IMO would not only increase safety but also fuel savings (especially if we had them for each signal change) as I could time my arrival at the traffic light to minimize braking and acceleration.