Tips for Driving in Orlando, they might save you from a accident or save your life.

[MillauFr]

Except when the zipper merge is on an incline and the heavy vehicles cannot get up enough speed.

Agreed. It is generally a poor design to have lane reduction on a long steep uphill climb.

 

[MillauFr]

There are differing expert opinions. One thing is for certain, there are no absolutes in traffic engineering.

Agreed. I have seen some heated discussions at Institute of Transportation Engineers conferences. You'll have one group of engineers who claim that all of the research claims that idea A is best. The other group of engineers who counter that idea A is very unpopular with the general public. I'm sure the first group never hears all of the public complaining. The second group is too quick to respond to the whims of the public. There has to be balance.