My Prius Prime has an automatic radar cruise control which works pretty well in traffic jams - it will speed up and slow down with the car in front of it (inclu

My Prius Prime has an automatic radar cruise control which works pretty well in traffic jams - it will speed up and slow down with the car in front of it (including coming to a stop and starting again). The only problem is that even at the closest of the following distances it will let you select, it hangs back a bit, which encourages other drivers to try and cram themselves in (which then causes the Toyota to fall back again, and on and on). Still, fairly effective.