But there are other potential benefits, such as minimizing emissions and vehicle fuel consumption. “Why should we incur an extra stop which consumes more fuel and emits more emissions?” Rakha asked. “If you stop when you weren’t supposed to stop, you’ll stop very aggressively, which could cause an accident, a rear-end crash for someone behind you. The fact that you’re stopping does not mean that you’re a better driver. It could mean that you’re more dangerous.”
When will any of this take place? Rakha said that the DOT requires a rigorous process before changing their procedures for designing yellow interval durations. This is typically mandated federally from the Institute for Transportation Engineers (ITE) or AASHTO.
Rakha added that he plans to approach the DOT to see if his group can gather additional data to design specific yellow timings and test them in the field for real drivers.
With development occurring now on V-to-I and I-to-V communication systems, perhaps the horizon for longer yellow times isn’t all that far off. On the other hand, when and if self-driving cars become a reality, the need may be moot – at least on certain roadways.
In the meantime, we can perhaps draw our own conclusions from Rakha’s research about driver reaction times, approach speed and distance from a signalized intersection, in making a personal decision whether to stop or go. While Rakha emphasized he cannot recommend stop or go, what he can do is recommend to traffic engineers ways that they can come up with a better plan for yellow times.