Better Way To Change From Green Light to Red
When signal lights change from green to red, the sequence should be first green only, then yellow only, then yellow and red at the same time, then red only. This entire sequence should last around twice as long as the current yellow only light lasts. This would better indicate to drivers when the light will change from green to red and give them more time to prepare to stop, preventing them from hitting hard on the brakes.
Very Low Traffic Signal Controlled Intersections
The signal lights for traffic on main roads that intersect smaller streets should be set continuously on green (or perhaps with a green and yellow light blinking in series) during periods of low traffic flow such as during the hours between 12 AM and 5 AM. Traffic on the intersecting smaller side streets would see their signals blinking red and yellow in series. The blinking red light would tell drivers to stop and the blinking yellow would warn drivers to be cautious because cross traffic has the green light and the right of way. (If drivers see only a red light blinking they might erroneously think that it is an all way stop leading to a higher risk of accidents.)