I have been in situations where low traffic leads in just a few seconds to a traffic jam both on the streets and on the highway. https://tse1.mm.bing.net/th?&id=OIP.Mcb0d8b1940e2cf082bb67ef045975841o0&w=300&h=168&c=0&pid=1.9&rs=0&p=0&r=0 [Broken] Traffic jam on street https://tse1.mm.bing.net/th?&id=OIP.M835e36a3e28bd3c1f16ba7bada76f5bfo0&w=300&h=199&c=0&pid=1.9&rs=0&p=0&r=0 [Broken] Traffic jam on highway I most commonly see traffic jams on the highways and low traffic on the streets. But those traffic jams seem like they would lead to more and more traffic jams and spread across all the roads. However it is usually localized. I mean for example when I get home from Columbus State downtown, the first highway that comes up that I go on is I-71. This highway that goes from downtown Columbus to uptown Columbus always has some bad traffic but when going home from college, there is often a traffic jam on this highway. I get onto I-270 and there is no more traffic jam. Why does the traffic jam not spread and cause more traffic jams and could a traffic jam spread throughout a network of roads no matter how widespread the roads are(city, state, country, continent)?