It's also a trade off we made against pedestrian/cycling safety:

> The report findings show large percentage increases in right-turn accidents at signalized locations after RTOR (e.g., increases ranging from 43% to 107% for pedestrians, and increases ranging from 72% to 123% for bicyclists in the three states studied.)

People in the article linked to in this post can try to have it both ways, but ultimately I'd rather be stuck in a traffic jam than see people hit more frequently because someone wanted a few seconds of times savings on their commute.