Enjoy your trip on the Green Line

I found the Oct. 9 article, “Keeping the Green Line safe” regarding Green Line safety interesting.

Perhaps a safety engineer can inform the University of Minnesota community why there is a very noticeable rail bump and a dip between the tracks at every concrete sidewalk and street crossing. 

Is this lack of levelness placed there so people running can trip more easily, especially at night or in slippery weather?

I traveled all over the world and saw many kinds of trams and light rails. I have not seen any dips. Why are there dips on the Green Line?