1. Modify the code so that the lights all blink at the same time.

  2. Modify the code so that it has the “walk-pattern” used in Massachusetts (and in Sweden):

  1. Wikipedia has an interesting page
    describing the conventions of real traffic lights. For example, in some
    jurisdictions, the yellow light depends on the speed limit, adding 1s for each
    10 miles/hour. Set up another variable at the top of the program that
    specifies the speed limit. Also, declare a variable (called yellowTime)
    whose initial value is 0. Then in the setup() function, set the value of
    yellowTime so that it corresponds to your speed limit, and use the value