Fewer people on the roads driving is probably the biggest reason. And not many people working, either. Chicago thugs may even have slowed down the number of shootings out of fear they are more susceptible to getting sick. The number of illegals crossing the border has dropped as well. And, to a smaller degree, people not passing around other communicable diseases.
...and.... this president is not agitating for the shooting of cops and rioting. ;-)
Missed it on Chicago. This year is an average year so far per http://heyjackass.com/
Allstate is giving partial refunds to people carrying car insurance through them. So few accidents they felt guilty keeping the money.