Shockwave traffic jams

(Via Abstruse Goose.)
In my first year at Essex University (1969) I took a maths course which introduced us to the topic of partial differential equations. I had studied ordinary differential equations at the RGS in High Wycombe (part of the syllabus for “A” Level Maths), but PDEs were mind-blowing by comparison. (No, I don’t think this was due to any other mind-blowing substances that we were playing with.) Anyway, I remember that the lecturer started with the role of PDEs in fluid dynamics, and then switched to modelling shockwave traffic jams. Today it would be easy and natural to visualize the wave propagation on the computer, but in 1969 such techniques were still pretty esoteric.
Nice to see that the experimental side of applied mathematics isn’t being ignored.