To quote the speaker, ‘it’s this quick crossing (of lanes) that causes drivers to overbrake and begin a chain reaction’.
In theory, the solution is for all drivers to stay an equal distance from the vehicle in front and the vehicle behind – however, this doesn’t work very well because people won’t do it. A better solution would be to use self-driving cars, which can be programmed to move together with the other traffic. Self-driving cars can communicate with each other, so that there is no need for traffic lights and traffic jams are much less likely to start.
(This is part of a lesson on my main site – here’s the link).