alt Hacker NewsThe bit about the clothoid finally made me understand the odd shape of highway junctions. I always wondered why they want me to enter turns fast and then slow down progressively until the turn becomes a new straight. Unfortunately sometimes that straight is the highway, and they should give us plenty of space to build up speed and match the traffic inside the highway. Sometimes they do, sometimes they don't.
This is why I like Dutch road design, there's a legally required minimum (I think it's 200m, but 300m is more common) for onramps, and we are taught not to merge before you've reached the maximum speed on the road you're merging too, so that you cause minimal disturbance to the traffic currently there. (Think like a zipper.)
I live near the border with Germany, and these guys are used to short ramps and so just merge well below the speed other traffic are going, expecting others to yield. (And many locals also drive like that unfortunately.) So uncivilized.