Cars crash when dt high

[Blasylf]

Problem: see title. Not exactly sure what is causing it - initially I thought it had to do with:

• Cars spawning in with too fast speeds when traffic gets congested, hence having to break extremely quickly, but the high DT prevents this
• When cars crash, the distance between them and the car in front is understandably 0, but then as s0 >= 2, s0/s > 1, so the car will always tend to decelerate (even though it's crashed, i.e. v=0!)

See picture:

Paradoxically, in this case, infront = None! A car must've crashed somehow even though there is no car in front of it. I suspect cars 'overtake' before they check for crashes!

[Blasylf]

I think I fixed this, frustratingly, by swapping the order of operations. Instead of updating speed, then acceleration, acceleration is updated first.