 and you move into those spaces right at that merge point. Michelle says when people use both lanes, the traffic backup is 40 to 50% less. Whereas in cases where both lanes are not used, backup can be several miles long. Zipper merging, when done right, also reduces speeding. We want to try to keep speeds similar between the two lanes. It's just safer traveling. We don't have some people going exceptionally faster than others or slower than others.