Two lanes become one. This is a solved problem. It has been solved for decades. The solution is called taking turns, which children can do, and which adults in cars apparently cannot.
There are two kinds of people at a merge. The ones who move over a mile early and then seethe at everyone who did not, and the ones who drive to the very end and then seethe at everyone who will not let them in. Both groups are certain they are correct. Both groups are the reason it takes nine minutes to travel three hundred metres.
Zip. Like a zip. One from here, one from there. I will let you in. You will let the next one in. We will all arrive at roughly the same time and nobody will have to make eye contact.