Domestic, you had a vote for the question about the light at 29th and Amazon that JimJohnson raised. Here is a reply from a "sensible traffic engineer":  “I would say that the signal is sufficient, but could have other features (that were not implemented as they were not deemed necessary by the person responsible for the design at the time).” 
“Protected left turns should not coincide with a WALK signal. Flashing yellow arrows are permissive lefts ….with a WALK where the driver must yield. However, there is a Ped Minus Left phase implemented in some locations where conflicts [occur]. Another solution is … a leading pedestrian interval where peds get a WALK first before the autos get a green arrow.” 
Does it seem sensible to NOT allow a green arrow indicating motorists can turn into a crosswalk? Does it seem a tad more complicated than at first glance? If you want to know what engineers must consider read:  www.apsguide.org/chapter3_plans