How do I make a speed curve?

If you think about it, we all use this. if you are running at top speed, youstart to increase speed, gradually level out, and reach top speed. this should be trur in games, too. if you press the forward key, you do not shoot forward instantly at top speed, or at least you shouldn’t.

How would I code this concept into Unity 2018, with public variables that modify the top speed and how fast you reach top speed?

Try using public AnimationCurve to simulate how speed goes from 0 to 1, then multply this curve’s x axis evaluation with your speed.