THINGS WE'RE WONDERING ABOUT ST. LOUIS ROADS/TRAFFIC

We're working on a segment about St. Louis traffic issues. Here are some of the questions we've gathered that we would like answered. What are yours?
  1. Why does St. Louis have so many stop signs?
  2. Why are manhole covers 2 or 3 inches below street grade?
  3. Why are stoplight times so long?
  4. Who did the studies for a flashing yellow left turn arrow?
  5. Why does an interstate end at a Target?
    Suggested by   @ginana13